Publications

The improvement of Earth Observation (EO) sensors and modern computational efficiency in the form of cloud analytics platform has made monitoring and interpretation of floods much more efficient. In this study, we present the recently occurred floods in the north-central section of the Irrawaddy River, inundating the adjoining farmlands on the active floodplains along a stretch of 228 km. The amount of rainfall was observed to have gradually risen from early June 2022 captured through GPM data. Similarly, the water levels in the study stretch were observed to have increased from 98.08 m to 104.08 m (from Sentinel-3 altimetry) due to torrential rains on the northern hilly tracts of Myanmar. High-resolution Sentinel-1 SAR datasets have been used to estimate flood progression in the GEE platform. The total inundated area had risen from 196 to 989 sq. km. throughout June till the first week of July. Thus, EO data associated with accessible computing on cloud platforms help monitor flood progression, warn the community well in advance and support the development of crop insurance strategies, anticipatory actions and many more to strengthen evidence-based flood policy.

Irrigation is an important mechanism to mitigate risks associated with the variability in rainfall for the smallholder subsistence farming system. This study analyzed how practicing small-scale irrigation (SSI) impacts the key livelihood assets on farm households’ human, physical, natural, financial, and social capitals in Ethiopia’s upper Awash sub-basin. The household-level survey data, collected from the 396 sample households, was used to carry out the current study. A Propensity Score Matching (PSM) analytical model was applied to match the SSI user and nonuser groups. The difference between the five capital assets of livelihood was estimated using the PSM’s Nearest Neighbor, Radius, Kernel Mahalanobis, and Stratification matching criteria. The results indicated that farmers’ participation in SSI has enhanced the capital assets of the farm households. Compared to the non-users, the irrigation users were better off in the number variety of food consumed (0.28 0.13 Standard Error [SE]), types of crops produced (0.60 0.17 SE), expenditures on land renting, and agricultural inputs (3118 877 SE) measured in Ethiopian Birr (ETB), as well as on-farm (9024 2267 SE ETB) and non-farm (3766 1466 SE ETB) incomes. Challenges such as the involvement of local brokers in the market value chain and the absence of farmers’ marketing cooperatives have reduced the benefit of irrigated agriculture. Hence, the expansion of SSI schemes for the non-user farmers should consider improving the water usage mechanism and productivity, establishing proper water allocation institutions between up and down streams and limiting the role of brokers in the irrigation product marketing chain be future policy directions.

Various precipitation-related studies have been conducted on the Yangtze River. However, the topography and atmospheric circulation regime of the Source Region of the Yangtze River (SRYZ) differ from other basin parts. Along with natural uniqueness, precipitation constitutes over 60% of the direct discharge in the SRYZ, which depicts the decisive role of precipitation and a necessary study on the verge of climate change. The study evaluates the event distribution of long-term variability in precipitation classes in the SRYZ. The precipitation was classified into three precipitation classes: light precipitation (0–5 mm, 5–10 mm), moderate precipitation (10–15 mm, 15–20 mm, 20–25 mm), and heavy precipitation (gt;25 mm). The year 1998 was detected as a changing year using the Pettitt test in the precipitation time series; therefore, the time series was divided into three scenarios: Scenario-R (1961–2016), the pre-change point (Scenario-I; 1961–1998), and the post-change point (Scenario-II; 1999–2016). Observed annual precipitation amounts in the SRYZ during Scenario-R and Scenario-I significantly increased by 13.63 mm/decade and 48.8 mm/decade, respectively. The same increasing trend was evident in seasonal periods. On a daily scale, light precipitation (0–5 mm) covered most of the days during the entire period, with rainy days accounting for 83.50%, 84.5%, and 81.30%. These rainy days received up to 40%, 41%, and 38% of the annual precipitation during Scenario-R, Scenario-I, and Scenario-II, respectively. Consequently, these key findings of the study will be helpful in basin-scale water resources management.

Climate change is affecting the agriculture, water, and energy sectors in East Africa and the impact is projected to increase in the future. To allow adaptation and mitigation of the impacts, we assessed the changes in climate and their impacts on hydrology and hydrological extremes in East Africa. We used outputs from seven CMIP-6 Global Climate Models (GCMs) and 1981–2010 is used as a reference period. The output from GCMs are statistically downscaled using the Bias Correction-Constructed Analogs with Quantile mapping reordering method to drive a high-resolution hydrological model. The Variable Infiltration Capacity and vector-based routing models are used to simulate runoff and streamflow across 68,300 river reaches in East Africa. The results show an increase in annual precipitation (up to 35%) in Ethiopia, Uganda, and Kenya and a decrease (up to 4.5%) in Southern Tanzania in the 2050s (2041–2070) and 2080s (2071–2100). During the long rainy season (March–May), precipitation is projected to be higher (up to 43%) than the reference period in Southern Ethiopia, Kenya, and Uganda but lower (up to -20%) in Tanzania. Large parts of Kenya, Uganda, Tanzania, and Southern Ethiopia show an increase in precipitation (up to 38%) during the short rainy season (October–December). Temperature and evapotranspiration will continue to increase in the future. Further, annual and seasonal streamflow and hydrological extremes (droughts and floods) are projected to increase in large parts of the region throughout the 21st century calling for site-specific adaptation.

The paper proposes a probabilistic approach to the assessment of the impacts of multipurpose dams. It is framed around the notion of Nature’s Contributions to People (NCP) in the setting of the Water-Energy-Food nexus. The socio-ecological context of the Tana River Basin in Kenya and the construction of two multipurpose dams are used to highlight co-produced positive and negative NCP under alternative river regimes. These regimes produce both damaging floods that ought to be controlled and beneficial floods that ought to be allowed. But the river regime that results from hydropower generation and flood risk reduction may not be the one that is most conducive to food and feed-based NCP. The approach relates the economic value of river-based NCP coproduction to the probability of flooding to derive the expected annual value of NCP and a NCP value-probability curve. The relation between NCP flows and flood characteristics is tested and estimated based on regression analyses with historical data. Results indicate that the net economic value of key NCP associated with multipurpose dams for local people and associated social equity effects largely depend on the frequency of flood events and on the way impacts are distributed across communities, economic sectors and time.

For the first time in the latest Assessment Report of the Intergovernmental Panel on Climate Change (IPCC), water has been the focus of dedicated chapters in both Working Group 1 (Chapter 8) and 2 (Chapter 4). Nevertheless, we argue here that water has not yet received the full attention it deserves from both scientists and policymakers for several reasons. Firstly, the historical focus on temperature change has been further increased with the use of global warming levels motivated by an aim to be consistent with current policy framings. Secondly, an increasing attention paid to extreme weather has sometimes overshadowed longer time-scale changes such as the aridification of an increasing fraction of arable land and the increasing variability of the water cycle from month to month, season to season, and year to year that also yield cascading impacts on all water use sectors. Thirdly, a stronger focus is needed on understanding the effectiveness of current and future adaptation strategies in reducing water-related climate risks. Finally, the role of water has not been adequately recognized in the assessment of mitigation strategies although the compliance with the Paris Agreement and the current pledges all require a massive deployment of land-based strategies whose feasibility and efficiency heavily depend on water resources. It is thus essential to develop a more integrated approach to water and climate change, that would allow scientists and policymakers to “close the loop” between mitigation options, water cycle changes, hydrological impacts and adaptation.

Over the last two decades, several data sets have been developed to assess flood risk at the global scale. In recent years, some of these data sets have become detailed enough to be informative at national scales. The use of these data sets nationally could have enormous benefits in areas lacking existing flood risk information and allow better flood management decisions and disaster response. In this study, we evaluate the usefulness of global data for assessing flood risk in five countries: Colombia, England, Ethiopia, India, and Malaysia. National flood risk assessments are carried out for each of the five countries using six data sets of global flood hazard, seven data sets of global population, and three different methods for calculating vulnerability. We also conduct interviews with key water experts in each country to explore what capacity there is to use these global data sets nationally. We find that the data sets differ substantially at the national level, and this is reflected in the national flood risk estimates. While some global data sets could be of significant value for national flood risk management, others are either not detailed enough, or too outdated to be relevant at this scale. For the relevant global data sets to be used most effectively for national flood risk management, a country needs a functioning, institutional framework with capability to support their use and implementation.

Study region: The study region is the Kamadhiya catchment (1150 km2 ), located in the Saurashtra region of the western state of Gujarat, India. The region has seen intensive development of check dams (CDs) for groundwater recharge with an estimated 27,000 CDs constructed up until 2018. Study focus: The impact of CDs on groundwater storage, food production and resilience are assessed for Kamadhiya catchment by estimating and comparing changes, across periods of low and high CD development, in potential recharge from CDs, rainfall trends, and irrigation demand. The analysis is carried out for the period from 1983 to 2015. New hydrological insights for the region: Groundwater storage gains observed following CD development can partly be attributed to an increase in high rainfall years after several drought years. Groundwater demand for irrigation has increased substantially, outweighing increase in groundwater recharge from CDs. This deficit in supply relative to demand is greatest in dry years, and when considered together with the low inter-annual carry-over storage of the region’s hardrock aquifers, means that CDs capacity to enhance groundwater storage and mitigate the negative impacts of drought remains limited. Findings suggest that a standalone focus on MAR, unless complemented by greater emphasis on management of water demand and groundwater resources more broadly, may not be sufficient to achieve the long-term goals of sustainable groundwater and concurrently expanding agricultural crop production.

The use of improved technologies has been encouraged to improve irrigation on farms, especially in drought-prone areas. However, farmersapos; irrigation decisions may be rather motivated by a desire to reduce risk of crop loss than to reduce water use. Using the case of Jordan, we contribute to the water-saving debate by examining whether current irrigation frequency is influenced by past experiences of losses due to water shortage and whether preferences for technologies and irrigation advisory services are mediated by water shortage experiences. Our data are based on a survey of 304 fruit farms in the highlands that were all using drip irrigation, a popular way to “save” water globally. We find that farms that faced losses due to water shortages in the past are more likely to irrigate more frequently. More frequent irrigators who have such shortages are more likely to prefer receiving irrigation advisory information rather than upgrading technologies, while more frequent irrigators who have not faced such shortages are more likely to prefer upgrading irrigation technologies. Results suggest that irrigation management is motivated by risk reduction, not just by water conservation. Irrigation advisory services, hitherto neglected, may be an important component of agricultural water management in Jordan.

Drought-related risk is among the major global challenges of our time. It negatively impacts food security and ecosystem health. It is becoming a persistent problem in many parts of sub-Saharan Africa and specifically in Ethiopia. Information on its intensity and spatiotemporal distribution is critical to contextualize interventions and build agroecosystem and community resilience. This study aims at analyzing spatiotemporal characteristics of meteorological drought over eight Agroecological Zones (AEZs) of the Awash Basin, Ethiopia. Annual gridded temperature and precipitation dataset obtained from the National Meteorological Agency of Ethiopia for the period 1983–2016, covering 1655 grid points, were used. The study applied the Standard Precipitation and Evapotranspiration Index (SPEI) and Standard Precipitation Index (SPI) methods to characterize the meteorological droughts. The study applied Arc GIS 10.5 to map the drought hotspots. From the result, the value of SPEI and SPI methods was divergent in characterizing the magnitude and spatial occurrence of drought episodes. SPEI has more advantages in detecting dry months and a small advantage in detecting dry seasons compared to the SPI. Temporally, wet and dry years dominated the 1990s and 2010s, respectively. Drought dominated 1980s and normal years dominated the 2000s. The spatial context of drought hotspot showed that AEZs in the upper and lower parts of the Awash Basin were hit by severe to extreme drought while the escarpments and middle parts of the basin experienced mild to moderate drought. This contrasts with the common perception that the hot to warm arid lowlands AEZs are the only hotspot areas to drought. Moreover, previously none frequent drought AEZs, such as tepid to cool humid mid-highlands were identified as drought hotspots in the basin. This information could help policymakers to target AEZs and implement context-specific and informed drought risk management decisions and adaptation measures.

Adoption of climate smart agricultural (CSA) practices has been widely recognized as a promising and successful alternative to minimize the adverse impacts of climate change. However, their adoption among smallholder farmers remains low in developing countries, including Ethiopia. This study examines factors that influence adoption and the level of adoption of multiple CSA practices, including improved agronomy, soil and water conservation, drought tolerant high yielding crop variety, small-scale irrigation, integrated disease, pest, and weed management, and integrated soil fertility management, using survey data from 404 farm households in BaleEco Region (BER), Ethiopia. The study applied a multivariate probit model for analyzing the simultaneous adoptions of multiple CSA practices, and ordered probit model for examining the factors influencing the level of adoption. The CSA practices are found to be complementary. Moreover, farmersapos; adoption of multiple CSA practices, as well as their intensity of adoption, is significantly influenced by the age of the household head, education, land size, household total asset value, frequency of extension contacts, farmer awareness of climate change, farmer experience with climatic shocks, parcel fertility, slope, and severity of soil erosion. The studyapos;s findings suggest that agricultural policy makers and implementers of CSA should recognize the complementarity among CSA practices in order to intensify their adoption among BER farmers and disseminate CSA practices in other parts of the country. Moreover, policymakers should consider household socio-economic, institutional, and parcel-specific factors that positively influence CSA adoption.

The Sentinel-1 SAR dataset provides the opportunity to monitor floods at unprecedentedly high spatial and temporal resolutions. However, the accuracy of the flood maps can be affected by the image polarization, the flood detection method used, and the reference data. This research compared change detection and histogram thresholding methods using co-polarization (VV) and cross-polarization (VH) images for flood mapping in the Akaki catchment, Ethiopia, where Addis Ababa city is located. Reference data for the accuracy assessment were collected on the satellite overpass date. A new method, Root of Normalized Image Difference (RNID), has been developed for change detection. Multi-temporal flood maps using the best performing method and image polarization were generated from April to November of 2017–2020. Better accuracy was observed when using the RNID method on the VH polarization image with an overall accuracy of 95% and a kappa coefficient of 0.86. Results showed that flooding in the Akaki commonly begins in May and recedes in November, but flooding was most frequent and widespread from June to September. Irrigated land and built-up area accounted for 1057 ha and 544 ha of the inundated area, respectively. Several major roads in the study area were also affected by the floods during this period. Our findings indicate that the S-1 images were very useful for flood inundation mapping, the new change detection method (RNID) performed better in urban and peri-urban flood mapping, but the accuracy of the flood map significantly varied with the flood detection method and the image polarization.

The effects of climate change are likely to increase the frequency of flood, drought, and salinity events in the coastal areas of Bangladesh, posing many challenges for agrarian communities. Sustainable intensification in the form of improved agricultural management practices and new technologies may help farmers cope with stress and adapt to changing conditions. In this study, we explore how climate change perceptions of agricultural risk affect adaptation to climate change through technology adoption in a unique landscape: the polders of Bangladesh. In 2016, a survey was conducted in 1003 households living on these artificial, leveed islands facing the Bay of Bengal. We analyzed the responses from polder residents to construct a climate risk index which quantifies climate risk perception in this highly vulnerable agrarian landscape. We analyzed how polder demographics influence their perceptions about climatic change using seemingly unrelated regression (SUR). Further, by using three bivariate probit regression models, we estimated how the perception of climate risk drives the differential adoption of new agricultural technologies. Our findings show that farmers perceive polder agriculture as highly vulnerable to four environmental change factors: flooding, drought, salinity, and pest infestation. The SUR model suggests that farmer demographics, community group memberships, and access to different inputs and services strongly influence climatic risk perceptions. Findings also suggest that polder farmers with higher risk perceptions have a higher propensity to adopt both chemical and mechanical adaptation strategies. Cost, however, limits the ability of farmers to adopt improved technologies, suggesting an opportunity for institution-led approaches.

Cascading hazards are becoming more prevalent in the central Himalayas. Primary hazards (e.g., earthquakes, avalanches, and landslides) often trigger secondary hazards (e.g., landslide dam, debris flow, and flooding), compounding the risks to human settlements, infrastructures, and ecosystems. Risk management strategies are commonly tailored to a single hazard, leaving human and natural systems vulnerable to cascading hazards. In this commentary, we characterize diverse natural hazards in the central Himalayas, including their cascading mechanisms and potential impacts. A scientifically sound understanding of the cascading hazards, underlying mechanisms, and appropriate tools to account for the compounding risks are crucial to informing the design of risk management strategies. We also discuss the need for an integrated modeling framework, reliable prediction and early warning system, and sustainable disaster mitigation and adaptation strategies.

Improving the preparedness of agricultural systems to future climate-change-induced phenomena, such as drought-induced water stress, and the predictive analysis of their vulnerability is crucial. In this study, a hybrid modeling approach based on the SWAT model was built to understand the response of major crops and streamflow in the Bouregreg catchment in Morocco to future droughts. During dry years, the simulation results showed a dramatic decrease in water resources availability (up to -40%) with uneven impacts across the study catchment area. Crop-wise, significant decreases in rainfed wheat productivity (up to -55%) were simulated during future extremely dry growing seasons.

Drought is a complex phenomenon affecting agricultural, environmental, water resources, and socio-economic systems in developing regions. Climate change is going to increase the frequency and intensity of drought events and the associated socio-economic impact, including that on the food security among marginal smallholder farmers. For timely early action, it is important to have robust drought monitoring and warning in place to determine the timely drought situation to assist end-users for the decision-making process. Spatialtemporal remote sensing data provides crucial information on near real-time drought monitoring and early warning. The present study developed a composite index, i.e., Integrated Drought Severity Index (IDSI) that combines inputs from rainfall, vegetation, and temperature to determine agricultural drought progression, intensity, and frequency for entire Sri Lanka between 2001 and 2019. The study has successfully identified 10 drought events of which 2001, 2012, 2017, and 2019 reported severe droughts across the two rainy seasons, namely Yala (May–August) and Maha (October–March). We analyzed various indices meteorological drought Standardized Precipitation Index (SPI) and field-based rice Crop Yield Anomaly Index (CYA). It is evident from the study that the Yala season reported more drought events compared to the Maha season due to changes in monsoon onset and duration and its seasonal variability. The correlation coefficient for SPI with IDSI is 0.70 and IDSI with CYA is 0.68, which explains the reliability of drought monitoring information across Sri Lanka. In terms of sub-national drought events, the North, North Central, North Eastern, Eastern, and South Eastern Provinces which cover the majority of the dry zone of Sri Lanka and districts such as Anuradhapura, Monaragala, Polonnaruwa, Hambantota, Trincomalee, and Ampara are highly prone to agricultural drought impacting agricultural production and the vulnerable rural population. From the basin analysis, both Yan Oya and Malwathu Oya (Aruri Aru) are reported to have severe drought events, which highlights the need for timely action using satellite-derived agricultural drought monitoring to mitigate drought risks and reduce food insecurity.

Global warming-induced melting and thawing of the cryosphere are severely altering the volume and timing of water supplied from High Mountain Asia, adversely affecting downstream food and energy systems that are relied on by billions of people. The construction of more reservoirs designed to regulate streamflow and produce hydropower is a critical part of strategies for adapting to these changes. However, these projects are vulnerable to a complex set of interacting processes that are destabilizing landscapes throughout the region. Ranging in severity and the pace of change, these processes include glacial retreat and detachments, permafrost thaw and associated landslides, rock–ice avalanches, debris flows and outburst floods from glacial lakes and landslide-dammed lakes. The result is large amounts of sediment being mobilized that can fill up reservoirs, cause dam failure and degrade power turbines. Here we recommend forward-looking design and maintenance measures and sustainable sediment management solutions that can help transition towards climate change-resilient dams and reservoirs in High Mountain Asia, in large part based on improved monitoring and prediction of compound and cascading hazards.

Rapid climate change is causing weather extremes in every region of the world. The global water cycle is now experiencing a structural change not seen since the last Ice Age, leaving human systems struggling to adapt and respond. Some events will have noticeable consequences in the short term, such as increased flooding from changing precipitation patterns. Others will be more long term, such as the desertification of cropland. All will have major implications for future human security. We can view climate security as climatic stressors that amplify existing risks in society and influence the security of humans, ecosystems, economies, infrastructure and societies. In that sense, climate security is directly connected to water security defined as the ability of a population to safeguard sustainable access to adequate quantities of acceptable quality water.

Producing more food for a growing population requires sustainable crop intensification and diversification, particularly in high-potential areas such as the seasonal floodplain wetlands of sub-Saharan Africa (SSA). With emerging water shortages and concerns for conserving these multi-functional wetlands, a further expansion of the cropland area must be avoided as it would entail increased use of blue water for irrigation and infringe on valuable protected areas. We advocate an efficient use of the prevailing green water on the existing cropland areas, where small-scale farmers grow a single crop of rainfed lowland rice during the wet season. However, soil moisture at the onset of the rains (pre-rice niche) and residual soil moisture after rice harvest (post-rice niche) may suffice to cultivate short-cycled crops. We developed a methodological approach to analyze the potential for green water cultivation in the pre- and post-rice niches in the Kilombero Valley Floodplain in Tanzania, as a representative case for seasonal floodplain wetlands in SSA. The three-step approach used open-access remote sensing datasets to: (i) extract cropland areas; (ii) analyze soil moisture conditions using evaporative stress indices to identify the pre- and post-rice niches; and (iii) quantify the green water availability in the identified niches through actual evapotranspiration (AET). We identified distinct patterns of green water being available both before and after the rice-growing period. Based on the analyses of evaporative stress indices, the pre-rice niche tends to be longer (~70 days with average AET of 20–40 mm/10-day) but also more variable (inter-annual variability gt;30%) than the post-rice niche (~65 days with average AET of 10–30 mm/10-day, inter-annual variability lt;15%). These findings show the large potential for cultivating short-cycled crops beyond the rice-growing period, such as green manure, vegetables, maize, and forage legumes, by shifting a portion of the nonproductive AET flows (i.e., soil evaporation) to productive flows in form of crop transpiration. A cropland area of 1452 to 1637 km2 (53–60% of the total cropland area identified of 2730 km2) could be cultivated using available green water in the dry season, which shows the significance of such change for food security, livelihoods, and resilience of the agricultural community in Kilombero. A wider application of the developed approach in this study can help identifying opportunities and guiding interventions and investments towards establishing sustainable intensification and diversification practices in floodplain wetlands in SSA.

The phenomenon of drought is common in the world, especially in Pakistan. El Nio-Southern Oscillation (ENSO) influences the spatial and temporal variability of drought and rainfall in Pakistan. Therefore, the objectives of this study are to identify homogeneous rainfall regions and their trend regions, as well as the impact of ENSO phases. In this study, monthly rainfall data from 44 weather stations are used during 1980–2019. Moreover, descriptive and exploratory statistics tests (e.g., Pettitt and Mann-Kendall—MK), Sen method, and cluster analysis (CA) are evaluated along with the annual Standardized Precipitation Index (SPI) on spatiotemporal scales. ENSO occurrences were classified based on the Oceanic Nino Index (ONI) for region 3.4. Using the cophenetic correlation coefficient (CCC) and a significance level of 5%, seven methods were applied to the rainfall series, with the complete method (CCC gt; 0.9082) being the best. According to the CA method, Pakistan has four groups of homogeneous rainfall (G1, G2, G3, and G4). Descriptive and exploratory statistics showed that G1 differs from the other groups in size and spatial distribution. Pettitt’s technique identified the most extreme El Nio years in terms of spatial and temporal drought variability, along with the wettest months (March, August, September, June, and December) in Pakistan. Non-significant increases in Pakistan’s annual precipitation were identified via the MK test, with exceptions in the southern and northern regions, respectively. No significant increase in rainfall in Pakistan was found using the Sen method, especially in regions G2, G3, and G4. The severity of the drought in Pakistan is intensified by El Nio events, which demand attention from public managers in the management of water resources, agriculture, and the country’s economy.

Kachchh, the westernmost district of India is historically known for its unique landscape, distinct traditions and arid climate. For a long time, the arid region of Kachchh had limited economic growth and limited habitation due to water scarcity caused by erratic rainfall. In 2001, the seismically active region of Kachchh experienced a large earthquake measuring 7.7 Mw but, the region has shown considerable development post-disaster. Growth strategies for agriculture, manufacturing and tourism implemented by the government and supported by industries and other agencies have not only made the region a dynamic economic hub in the state of Gujarat, but also has highlighted the long-neglected region on the world map. Due to the lack of perennial surface water availability and limited rainfall, the development has been fuelled by exploiting the groundwater resources to a great extent. The objective of this chapter is to highlight groundwater use in Kachchh, known as one of the most arid regions of India with low rainfall and high variability. Groundwater is playing a vital role in meeting the demand for all societal usage, irrigation, domestic requirements and industries. The authors highlight how the region is blessed with a suitable geological formation, forming a potential freshwater aquifer system which has served society for centuries even with a grossly adequate recharge. They highlight the importance of looking into the sustainable use of groundwater, a priceless natural resource of the region.

Most development planners and practitioners have often wrongly assumed that solutions for community challenges lie within the “western scientific knowledge” only. However, the recent studies have highlighted the relevance of Indigenous Knowledge to inform western scientific solutions. This study is on the Barotse Flood Plain of the Western Province of Zambia. Flood inundation understanding by the local communities has direct implications for their livelihood options and for the well-being of their households. The research found that there are a number of important local knowledge systems that are early warning systems based on observations of weather, water level and landscape, and animal behavior, which are widely disseminated through a specific communication network. The chapter concludes with a discussion on how the integration of Western scientific and Indigenous Knowledge Systems will better inform interventions to improve livelihood options for the communities within the Barotse Flood Plain and policy and practice within the developing world at large.

This study reports a comprehensive review on drought indices used in monitoring meteorological, agricultural, hydrological, and socio-economic drought. Drought indices have been introduced as an important approach to quantitative and qualitative calculations of drought’s severity and impact. There were 111 drought indices reviewed in this study, which fall into two categories: traditional (location-specific/model) and remote sensing (RS). Out of 111 indices, 44 belong to the traditional indices and 67 belong to the RS section. This study shows that meteorological drought monitoring has the highest number (22) of traditional indices, about 20% overall, while the lowest (7) agricultural drought monitoring is 6.3%. The specialty is that when considering remote sensing-based drought indices, 90% are used for agricultural drought monitoring and 10% for hydrological and meteorological drought monitoring. However, the study found that advances in satellite technology have accelerated the design of new drought indices and that replacing traditional location-specific data with satellite observation makes it easier to calculate more spatial distribution and resolution.

Groundwater is a significant resource that supports almost one-fifth population globally, but has been is diminishing at an alarming rate in recent years. To delve into this objective more thoroughly, we calculated interannual (2002–2020) GWS (per grid) distribution using GRACE amp; GRACE-FO (CSR-M, JPL-M and SH) Level 3 RL06 datasets in seven Indian river basins and found comparatively higher negative trends (-20.10 1.81 to -8.60 1.52 mm/yr) in Basin 1–4 than in Basin 5–7 (-7.11 0.64 to -0.76 0.47 mm/yr). After comparing the Groundwater Storage (GWS) results with the CHIRPS (Climate Hazards Group Infrared Precipitation with Stations) derived SPI (Standardized Precipitation Index) drought index, we found that GWS exhausts analogously in the same period (2005–2020) when SPI values show improvement (~ 1.89–2), indicating towards wet condition. Subsequently, the GWSA time series is decomposed using the STL (Seasonal Trend Decomposition) (LOESS Regression) approach to monitor long-term groundwater fluctuation. The long term GWS rate (mm/yr) derived from three GRACE amp; GRACE-FO solutions vary from -20.3 5.52 to -13.19 3.28 and the GWS mass rate (km3 /yr) lie in range of -15.17 4.18 to -1.67 0.49 for basins 1–3. Simultaneously, in basin 4–7 the GWS rate observed is -8.56 8.03 to -0.58 7.04 mm/yr, and the GWS mass rate differs by -1.71 0.64 to -0.26 3.19 km3 /yr. The deseasonalized GWS estimation (2002–2020) states that Himalayan River basins 1,2,3 exhibit high GWS mass loss (-260 to -35.12 km3 ), with Basin 2 being the highest (-260 km3 ). Whereas the Peninsular River basin 4,6,7 gives moderate mass loss value from -26.72 to -23.58 km3 . And in River basin 5, the GWS mass loss observed is the lowest, with a value of -8 km3 . Accordingly, GPS (Global Positioning System) and SAR (Synthetic Aperture Radar) data are considered to examine the land deformation as an effect due to GWS mass loss. The GPS data acquired from two IGS stations, IISC Bengaluru and LCK3 Lucknow, negatively correlates with GWS change, and the values are ~ -0.90 to ~-0.21 and ~-0.7 to -0.4, respectively. Consequently, correlation between GWS mass rate (km3 /yr) and the SAR (Sentinel-1A, SBAS) data procured from Chandigarh, Delhi, Mehsana, Lucknow, Kolkata and Bengaluru shows ~ 72 – 48% positively correlated area (PCA). The vertical velocity ranges within ~ -94 to -25 mm/yr estimated from PCA. There is an increase in population (estimated 2008–2014) in Basin 1 amp; 2. Likewise, the correlation coefficient ( ) between GWS change and the irrigational area is positive in all seven basins indicating significant depletion in GWS due to an uncalled hike in population or irrigational land use. Similarly, the positive linear regression (R 2 ) in Basins 1–3 also indicates high depletion in GWS. But basins 4–7 observe negative linear regression even after increasing population, which implies a control on the irrigational land use, unable to determine the GWS change at local scale a

Rice is one of the major staple foods in sub-Saharan Africa (SSA) and is mainly grown in three environments: rainfed upland and rainfed and irrigated lowlands. In all rice-growing environments, the yield gap (the difference between the potential yield in irrigated lowland or water-limited yield in rainfed lowland and upland and the actual yield obtained by farmers) is largely due to a wide range of constraints including water-related issues. This paper aims to review water management research for rice cultivation in SSA. Major water-related constraints to rice production include drought, flooding, iron toxicity, and soil salinity. A wide range of technologies has been tested by Africa Rice Center (AfricaRice) and its partners for their potential to address some of the water-related challenges across SSA. In the irrigated lowlands, the system of rice intensification and alternate wetting and drying significantly reduced water use, while the pre-conditions to maintain grain yield and quality compared to continuous flooding were identified. Salinity problems caused by the standing water layer could be addressed by flushing and leaching. In the rainfed lowlands, water control structures, Sawah rice production system, and the Smart-Valleys approach for land and water development improved water availability and grain yield compared to traditional water management practices. In the rainfed uplands, supplemental irrigation, mulching, and conservation agriculture mitigated the effects of drought on rice yield. The Participatory Learning and Action Research (PLAR) approach was developed to work with and educate communities to help them implement improved water management technologies. Most of the research assessed a few indicators such as rice yield, water use, water productivity at the field level. There has been limited research on the cost-benefit of water management technologies, enabling conditions and business models for their large-scale adoption, as well as their impact on farmers’ livelihoods, particularly on women and youth. Besides, limited research has been conducted on water management design for crop diversification, landscape-level water management, and iron toxicity mitigation, particularly in lowlands. Filling these research gaps could contribute to sustainable water resources management and sustainable intensification of rice-based systems in SSA.

While extreme rainfall events may provide rare opportunities for replenishment of surface water and groundwater resources in vulnerable (semi)arid areas, they are typically also associated with widespread flooding. The impacts on contaminant movement associated with spatio-temporally complex relationships between surface water and groundwater during such events in these regions are largely unknown. The catchment area (~4350 km2) upstream of Gaborone Dam on the Notwane River in south-east Botswana and northern South Africa experienced extreme rainfall and major flooding in 2016/17, following a severe 5-year drought. In this generally data-sparce area, we collected a unique data set that combined traditional water quantity observations with stable water isotope, major ion, trace metal and geophysical data. These were analysed to gain insights into water quantity and quality dynamics following flooding, including contaminant movement using trace metals as pollution indicators. Results revealed that the extreme rainfall and flooding was responsible for replenishment of surface water and groundwater resources, but also contaminant mobilisation from the surface. This subsequently resulted in increased concentrations of contaminants during the recession. Overall, hydrogeological heterogeneity dictated spatially variable surface water - groundwater interactions, characterised by poor connectivity in low productivity aquifer areas as opposed to good connectivity in moderate to high productivity aquifers. This in turn affected water quality dynamics and contamination, locally superimposed by land use impacts, primarily from urban landfill and local agricultural practices. Groundwater-connected streams had consistently lower (responses in) contaminants. We also found that Gaborone Reservoir facilitated prolonged conditions for recharge but likely also enhanced contamination of groundwater through maintaining a high water table in urban areas located immediately downstream. Management implications of our findings include a requirement for careful consideration of land use and landfill planning in relation to bedrock geology and presence of surface water reservoirs, conjunctive surface water and groundwater management, but also the need for even higher (space-time) resolution of monitoring in these data sparce environments. This could contribute to enhancing the benefits that extreme rainfall events provide in terms of surface water and groundwater resources replenishment for future dry seasons and periods of drought.

The report provides a methodology protocol for measuring temporal and spatial changes in water quantity and quality using drone imagery. The procedure is informed by the need for effective and sustainable water resource use to enhance water productivity under climate change. It is based on a literature review that allows the identification of appropriate processes, materials, and procedures for water monitoring, including mapping spatial and temporal dynamics of reservoirs, measurement of water quality parameters, and flood mapping of irrigation canals.

Assessing the magnitude of smallholder farmers’ livelihood vulnerability to drought is an initial step in identifying the causal factors and proposing interventions that mitigate the impacts of drought. This study aimed to assess smallholders’ livelihood vulnerability to the drought in the upper Awash sub-basin, Ethiopia. Household (HH) and climate data were used for indicators related to sensitivity, exposure, and adaptive capacity that define vulnerability to drought. The vulnerability of farmers’ livelihood to drought was compared among the studies agroecological zone (AEZ) and farm typologies. The result illustrated a diverse magnitude of vulnerability index (VI) ranging from -1.956 to -4.253 for AEZ. The highest magnitude of VI was estimated for livelihood in the lowland AEZ, while the lowest magnitude of VI was estimated in midland AEZ. This could be accounted for by the fact that lowland farmers shown the highest exposure (0.432) and sensitivity (0.420) and the lowest adaptive capacity (0.288). A closer look at farmers’ livelihood typology, in each of the AEZ, showed substantial diversity of farmers’ livelihood vulnerability to drought, implying potential aggregations at AEZ. Accordingly, the vulnerability index for livestock and on-farm-income-based livelihood and marginal and off-farm-income-based livelihood typologies were higher than the intensive-irrigation-farming-based smallholders’ livelihood typology. Based on the result, we concluded that procedures for smallholders’ livelihood resilience-building efforts should better target AEZ to prioritize the focus region and farmers’ livelihood typology to tailor technologies to farms. Although the result emphasizes the importance of irrigation-based livelihood strategy, the overall enhancement of farmers adaptive capacity needs to focus on action areas such as reducing the sensitivity and exposure of the households, improving farmers usage of technologies, diversify farmers’ livelihood options, and, hence, long-term wealth accumulation to strengthen farmers’ adaptive capacity toward drought impacts.

This research report presents the first comprehensive framework of business models in terms of developing, marketing and scaling Index-based flood insurance (IBFI). The report evaluated ten case studies on agricultural insurance schemes (macro, meso and micro levels), globally, to develop public-private partnership business models for creating value (product development) and capturing value (product marketing). This report highlights four broad groups of interrelated factors that influence the uptake and scaling of agricultural insurance: (i) behavioral factors that influence farmers’ enthusiasm to invest in insurance; (ii) financial factors that stipulate governments’ willingness to provide financial support; (iii) legal and regulatory factors, which set ground rules for fair business and govern their adherence by stakeholders; and (iv) facilitating factors, including product design and development, business models, research and development, data availability, and awareness creation, which help ensure an efficient supply of insurance services. In summary, the report highlights the need for designing innovative IBFI and its potential benefits for uptake, and efforts for implementing IBFI as a potential risk transfer tool for comprehensive climate risk management among small-scale and marginal farmers.

In spite of being water surplus, the 600+ million population of the large Ganges basin spread over 1.09 m km2 in South Asia is water insecure, poor, and highly exposed to water-induced stresses of floods and droughts. The contribution from the glaciers to the streamflow is ~70% in the Himalayan catchments though spatially distributed quantification is unavailable. An application of the Water Evaluation and Planning (WEAP) model with a sub-routine for snow and glaciers melt processes in the basin was set up. The model also examined the possible impacts of an increase in temperature of +1, +2 or +3C over 20 yrs of the simulation period. The impact on stream flows was high in the upstream (+8 to +26% at Tehri Dam) and moderate in downstream (+1 to +4% at Farakka). These increases shall create flood events more frequently or of higher magnitude in the mountains and Upper Ganga flood plains. To moderate the climate-change induced impacts of floods and improve water security during the non-monsoon season the novel concepts of Underground Taming of Floods for Irrigation (UTFI) and Cranking up the Ganges Water Machine for Ecosystem Services (GAMES) were developed, and pilot tested in the Ramganga sub-basin. Analysis showed that there is an assured possibility of reducing the floods and enhancing sub-surface storage in the identified basins to the level of 45 Bm3. The demonstrated managed aquifer recharge interventions are technically feasible, operationally acceptable and economically viable.

Relying on published literature, we reviewed water-energy-food issues in Lao PDR in the context of a policy shift to more sustainable ‘green growth’ and significantly increased infrastructure investment resulting from China’s Belt and Road Initiative. The BRI provides the prospect for the country to address its infrastructure deficit and transform from a ‘land-locked’ to a ‘land-linked’ country. However, great care is needed to ensure that future investments do not result in further environmental degradation and harm to communities. An integrated ‘nexus’ approach, in which enhanced water management is central, is a prerequisite for more inclusive and sustainable development.

This paper proposes scenarios to achieve more crop per drop and irrigation for all in water-scarce irrigation systems, with a particular reference to India. It uses economic water productivity (EWP) and water cost curve for EWP as tools to reallocate irrigation consumptive water use (CWU) and identify economically viable cropping patterns. Assessed in the water-scarce Sina irrigation system in Maharashtra, India, the method shows that drought-tolerant annual crops such as fruits and/or fodder should be the preferred option in irrigated cropping patterns. Cropping patterns with orchard or fodder as permanent fixtures will provide sustainable income in low rainfall years. Orchards in combination with other crops will increase EWP and value of output in moderate to good rainfall years. Governments should create an enabling environment for conjunctive water use and allocation of CWU to achieve a gradual shift to high-value annual/perennial crops as permanent fixtures in cropping patterns.

Analysis of long-term rainfall trends provides a wealth of information on effective crop planning and water resource management, and a better understanding of climate variability over time. This study reveals the spatial variability of rainfall trends in Sri Lanka from 1989 to 2019 as an indication of climate change. The exclusivity of the study is the use of rainfall data that provide spatial variability instead of the traditional location-based approach. Henceforth, daily rainfall data available at Climate Hazards Group InfraRed Precipitation corrected with stations (CHIRPS) data were used for this study. The geographic information system (GIS) is used to perform spatial data analysis on both vector and raster data. Sen’s slope estimator and the Mann–Kendall (M–K) test are used to investigate the trends in annual and seasonal rainfall throughout all districts and climatic zones of Sri Lanka. The most important thing reflected in this study is that there has been a significant increase in annual rainfall from 1989 to 2019 in all climatic zones (wet, dry, intermediate, and Semi-arid) of Sri Lanka. The maximum increase is recorded in the wet zone and the minimum increase is in the semi-arid zone. There could be an increased risk of floods in the southern and western provinces in the future, whereas areas in the eastern and southeastern districts may face severe droughts during the northeastern monsoon. It is advisable to introduce effective drought and flood management and preparedness measures to reduce the respective hazard risk levels.

Groundwater (GW) depletion and recurring floods have become a major concern among researchers and planners across the world. To rejuvenate stressed aquifer and moderate flood impacts, a modified version of managed aquifer recharge (MAR) consisting of a cluster of ten recharge wells (RWs) embedded in a community pond with an area of 2625 m2 and utilizing diverted floodwater was tested on a pilot scale in Ramganga sub basin, India. The approach could recharge a maximum of 72426 m3 of floodwater in 78 days during the wet season. The pond intervention minimized clogging of RWs by retaining maximum silt load of 68.01%. Hydro-geochemically, majority of water samples were of Mg-HCO3 and Ca-HCO3type. Ion exchange processes and weathering of carbonate and silicates were the controlling factors, determining water quality of the area. Total dissolved solids, fluoride, iron, zinc, manganese, chromium, cobalt, nickel, mercury, phosphate, nitrate, and ammonical nitrogen were found within the permissible limits as laid down by World Health Organization except arsenic and lead, which seems to be the inherent problem in the area, as evidenced by water quality analysis of farmers tube wells located upstream and down streams of the recharge site. The coliform presence in the 88.23% of sampled GW may thwart from direct use for drinking whereas it was fit for irrigation. Looking the benefits of modified MAR as a proactive GW quality improvement with good aquifer recharge, it is recommended for scaling up of the intervention across the GW stressed parts of the whole Ram Ganga basin and similar hydro-geological regions elsewhere.

Drought is an almost annual phenomenon in Sri Lanka, occurring at varying degrees of severity and affecting many parts of the country. These droughts cause significant damage to agriculture and other economic and social activities. This paper assesses the effectiveness of satellite-based weather Index insurance (WII) bundled with real-time climate and agronomic advisory services provided to farmers’ mobile phones. The aim is to enhance the drought resilience of diverse groups of farmers by providing solutions and strategies to extend bundled insurance products to more people and address equity issues. In this pilot, an insurance product was introduced to farmers in a village in the North Central Dry Zone of Sri Lanka. WII products are seen as a part of the solution to reducing farmers’ risk to climate change. However, in many places, the structure of insurance schemes in the agriculture sector has failed to reach small-scale and marginal farmers who are most in need of risk transfer mechanisms. Based on a farmer survey, we extracted lessons from implementing a bundled insurance scheme as a pilot project to explore the utility of farmer organizations as an entry point for engaging different farmer groups and ensuring they can understand the WII insurance products and can make informed choices. The survey results show that efforts made at the outset to understand contextual issues and challenges contributed to an effective product design and rollout approach. The rollout was more effective due in part to a partnership with an established local organization while adopting an aggregator model. Covid-19 mobility restrictions prevented full implementation of the rollout. Index insurance bundled with mobile weather and agronomic advisories increased farmer resilience and reached diverse groups. Farmers emphasized that being able to assess the costs and benefits based on understanding how key elements of the product work is key to their future engagement with such products, which highlights the importance of investing in awareness raising through a blend of print, verbal and visual tools that make complex products understandable to stakeholders with low levels of literacy.

Data exchange in transboundary waters is fundamental to advance cooperation in water management. Nonetheless, the degree to which data are actually shared is falling short of basin-level and international targets. A global assessment revealed that a reasonable proportion of river basins exchange some data, but the breadth of such exchange is often limited and not regular. More in-depth examination of African basins nonetheless suggests that a real need for, and use of, water data appears to motivate exchange. Indeed, evidence suggests that data exchange needs which are more directly felt enhance exchange, e.g., the direct need to minimize flood impacts or manage transboundary infrastructure. As such, data sharing is much more likely to be considered as being successful if it responds to a palpable need and serves practical uses. Also, in developing data exchange programs, it may be prudent to adopt a focused and sequential approach to data exchange that starts with a short-list of most needed parameters.

Drought is the most complex climate-related disaster issue in South Asia and has affected 1.46 billion people with an economic loss of over 7 billion USD in the last 56 years. South Asia is challenged with water, food, and energy security due to growing populations, incomes, resource degradation, and vulnerability to climate change. Monitoring of drought and associated agricultural production deficits using meteorological and agricultural indices is an essential component for drought preparedness. Remote sensing offers near real-time monitoring of drought conditions and IWMI’s has implemented South Asia Drought Monitoring System (SADMS) in 2014 as an online platform for drought early warning and support in drought declaration. This chapter explores the use of composite drought indices implemented in Google Earth Engine (GEE) and evaluates the crop yield variability during drought years. The study provides a rapid overview of drought-prone conditions that could enhance the present capabilities of early warning systems and enable science based policies for addressing water security in the agriculture sector and develop a drought response plan between water supply and demand, significantly increasing the vulnerability of regions to damaging impacts of drought events.

This paper assesses how the Huruluwewa tank (HWT) irrigation system in the North Central Province of Sri Lanka adapts to climate variability. The lessons learned in the HWT will be helpful for many water-scarce irrigation systems in the country, which bear high climate risks. Recurrent droughts are the bane of agriculture in the Dry Zone, comprising three-fourths of the land area spread over the Northern, North Central and Eastern provinces. In the HWT, the fifteenth largest canal irrigation system in the country, adaptation to climate variability happens on several fronts: changes made by the irrigation management to the water release regime; changes in the cropping patterns practiced by farmers in the command area; and the use of groundwater, which is recharged from rainfall, reservoir storage and canal irrigation, as supplemental irrigation. Such adaptation measures ensure that the available water supply in the reservoir is adequate for 100% cropping intensity over two cropping seasons, even in drought years, and enhances economic water productivity in terms of value per unit of consumptive water use. Moreover, irrigation management should consider groundwater recharge through canal irrigation as a resource, which brings substantial agricultural and economic benefits not only for the command area but also outside the command area. The adaptation patterns implemented in HWT demonstrate how water-scarce irrigation systems can achieve higher economic water productivity, i.e., generate ‘more income per drop’ to enhance climate resilience for people in and outside the canal command areas.

The International Water Management Institute (IWMI) has recently developed an innovative Index-based Flood Insurance (IBFI) product to facilitate the scaling of flood insurance particularly in vulnerable economies, to provide risk cover to poor farmers against crop losses that occur due to floods. While the product developed is technically very sound, the economics of such an intervention is important to ensure the large-scale acceptance and adoption of the product by different stakeholders and for its sustenance in the long term. This paper attempts at conducting an ex ante assessment of the economics of IBFI from the perspectives of the three main stakeholders: farmers, the insurance company and the government. The paper discusses the methodological challenges and data issues encountered in undertaking an economic analysis of such a product. The issues and processes involved have been empirically demonstrated using a theoretical case study based on a synthesis of information drawn from a host of sources and certain assumptions. Field-based data are now being collected and analyzed from the locations where IBFI has recently been piloted by IWMI. This will help in further refining the process of economic evaluation and identifying the experiences of different stakeholders.

Rice is the most important food crop. With the largest rain-fed lowland area in the world, flooding is considered as the most important abiotic stress to rice production in India. With climate change, it is expected that the frequency and severity of the floods will increase over the years. These changes will have a severe impact on the rain-fed agriculture production and livelihoods of millions of farmers in the flood affected region. There are numerous flood risk adaptation and mitigation options available for rain-fed agriculture in India. Procuring, maintaining and distributing the newly developed submergence-tolerant rice variety called Swarna-Sub1 could play an important role in minimizing the effect of flood on rice production. This paper assesses the quantity and cost of a flood-tolerant rice seed variety- Swarna-Sub1, that would be required during the main cropping season of rice i.e., kharif at a district level for 17 major Indian states. The need for SS1 seeds for rice production was assessed by developing a geospatial framework using remote sensing to map the suitability of SS1, to help stakeholders prepare better in managing the flood risks. Results indicate that districts of Bihar, West Bengal and Uttar Pradesh will require the highest amount of SS1 seeds for flood adaptation strategies. The total estimated seed requirement for these 17 states would cost around 370 crores INR, less than 0.01 percent of Indian central government’s budget allocation for agriculture sector.

The frequency and intensity of extreme climate events such as heavy rainfall and droughts are expected to increase with climate change and are predicted to severely affect the agriculture sector. However, drought vulnerability of rural communities in sub-Saharan Africa is not well documented, despite these communities being composed of mainly smallholder farmers whose livelihoods depend on rainfed agriculture. In this study, we evaluated the vulnerability of a rural community in Ethiopia to drought using both primary and secondary data. The primary data was generated from a household survey, whereas the secondary data was obtained from the National Meteorology Agency of Ethiopia and Climate Hazards Group Infrared Precipitation (CHIRP) product. We decomposed vulnerability in to three components which are exposure, sensitivity, and adaptive capacity to drought based on indices derived from the primary and secondary data. Results show that the average score for exposure, sensitivity, and adaptive capacity is nearly equal. High seasonal water variability coupled with severe, frequent, and long drought status increases exposure to drought in the study area. The main factor which affects sensitivity to drought in this community is the land cover. For adaptive capacity, the social capital of the community is low while their physical capital is high. The overall estimated drought vulnerability shows that the community is moderately vulnerable. The community’s exposure and sensitivity analyses show the need to increase the amount of moisture stored within the soil with the adoption of appropriate soil and water conservation techniques. Results also show that the head of the household’s educational level, the number of livestock owned, and annual income affect the community’s adaptive capacity.

This factsheet provides information on the general knowledge collected by the city region food system (CRFS) project in its phase 2 regarding the assessment of risks for the CRFS of Tamale. The data was collected through literature review and stakeholder consultations.

The Middle East and North Africa region experiences severe socioeconomic and political impacts during droughts and faces increasing drought risk in future climate projections. The UN Office for Disaster Risk Reduction’s Sendai Framework and the International Drought Management Programme provide a global standard (a norm) to manage droughts through natural hazard risk reduction approaches. We use participatory engagement to evaluate whether norm diffusion has taken place in four countries. Data were collected in interviews, focus groups, workshops, and policy documents. Analysis reveals incomplete norm diffusion; stakeholders subscribe to relevant values, but national policies and implementation do not fully reflect the norm. Process tracing reveals that the availability of drought early warning data is a key barrier to risk reduction. Further more, a drought early warning system would not be feasible or sufficient unless paired with policy measures and financial mechanisms to reduce the political and economic costs of a drought declaration.

Pragmatic, cost-effective, socially inclusive and scalable solutions that reduce risks from recurrent cycles of floods and droughts would greatly benefit emerging economies. One promising approach known as Underground Transfer of Floods for Irrigation (UTFI) involves recharging depleted aquifers with seasonal high flows to provide additional groundwater for irrigated agriculture during dry periods, while also mitigating floods. It has been identified that there is potential for implementing the UTFI approach across large parts of South Asia. The first pilot-scale implementation of UTFI was carried out in a rural community of the Indo-Gangetic Plain in India, and performance of the approach was assessed over three years from a technical, environmental, socioeconomic and institutional perspective. The results are promising and show that UTFI has the potential to enhance groundwater storage and control flooding, if replicated across larger scales. The challenges and opportunities for more wide-scale implementation of UTFI are identified and discussed in this report. In areas with high potential for implementation, policy makers should consider UTFI as an option when making decisions associated with relevant water-related development challenges.

For Sri Lanka, as an agricultural country, a methodical drought monitoring mechanism, including spatial and temporal variations, may significantly contribute to its agricultural sustainability. Investigating long-term meteorological and agricultural drought occurrences in Sri Lanka and assessing drought hazard at the district level are the main objectives of the study. Standardized Precipitation Index (SPI), Rainfall Anomaly Index (RAI), and Vegetation Health Index (VHI) were used as drought indicators to investigate the spatial and temporal distribution of agriculture and meteorological droughts. Climate Hazards Group Infrared Precipitation with Stations (CHIRPS) data from 1989 to 2019 was used to calculate SPI and RAI. MOD13A1 and MOD11A2 data from Moderate Resolution Imaging Spectroradiometer (MODIS) from 2001 to 2019, were used to generate the Vegetation Condition Index (VCI) and Temperature Condition Index (TCI). Agricultural drought monitoring was done using VHI and generated using the spatial integration of VCI and TCI. Thus, various spatial data analysis techniques were extensively employed for vector and raster data integration and analysis. A methodology has been developed for the drought declaration of the country using the VHI-derived drought area percentage. Accordingly, for a particular year, if the country-wide annual extreme and severe drought area percentage based on VHI drought classes is =30%, it can be declared as a drought year. Moreover, administrative districts of Sri Lanka were classified into four hazard classes, No drought, Low drought, Moderate drought, and High drought, using the natural-beak classification scheme for both agricultural and meteorological droughts. The findings of this study can be used effectively by the relevant decision-makers for drought risk management (DRM), resilience, sustainable agriculture, and policymaking.

This report presents a spatial analysis conducted at global scale to identify areas of high suitability for implementing the Underground Transfer of Floods for Irrigation (UTFI) approach. The study used multiple global spatial datasets, and the related data were arranged under three categories – water supply, water demand and water storage – to assess global UTFI suitability. Among the river basins with high suitability, the Awash in Ethiopia, Ramganga in India (one of the major tributaries of the Ganges River Basin) and Chao Phraya in Thailand were selected for the economic analysis in this study. The results from this study are intended to provide a first step towards identifying the broad areas (at the river basin or country scale) where more detailed investigation would be worthwhile to ascertain the technical and economic feasibility of UTFI, with greater confidence.

Built water infrastructure impacts the balance of services provided by a river and its flow regime. Impacts on both commercial and subsistence activities should be considered in water management decision-making. Various methods used to define mandatory minimum environmental releases do not account for the inherent and often complex trade-offs and synergies which must be considered in selecting a balance of ecosystem and engineered services. This paper demonstrates the value and use of optimised many-objective trade-off analysis for managing resource-systems providing diverse and sometimes competing services. Using Kenya’s Tana River basin as a demonstration it shows controlled releases from multi-reservoir systems can be optimised using multiple performance metrics, representing individual provisioning ecosystem and engineered services at different locations and relating to different time periods. This enables better understanding the interactions between natural and built assets, and selecting river basin interventions that appropriately trade-off their services. Our demonstration shows prioritising Kenya’s statutory minimum environmental ‘reserve’ flows degrades flood-related provisioning services. Low overall flow regime alteration correlates negatively with consistency of hydropower generation, but positively with other provisioning services.

Understanding the spatiotemporal distribution of future droughts is essential for effective water resource management, especially in the Mediterranean region where water resources are expected to be scarcer in the future. In this study, we combined meteorological and hydrological drought indices with the Soil and Water Assessment Tool (SWAT) model to predict future dry years during two periods (2035–2050and 2085–2100) in a typical Mediterranean watershed in Northern Morocco, namely, Bouregreg watershed. The developed methodology was then used to evaluate drought impact on annual water yields and to identify the most vulnerable sub-basins within the study watershed. Two emission scenarios (RCP4.5 and RCP8.5) of a downscaled global circulation model were used to force the calibrated SWAT model. Results indicated that Bouregreg watershed will experience several dry years with higher frequency especially at the end of current century. Significant decreases of annual water yields were simulated during dry years, ranging from -45.6% to -76.7% under RCP4.5, and from -66.7% to -95.6% under RCP8.5, compared to baseline. Overall, hydrologic systems in sub-basins under the ocean or high-altitude influence appear to be more resilient to drought. The combination of drought indices and the semi-distributed model offer a comprehensive tool to understand potential future droughts in Bouregreg watershed.

When drought hits water-scarce regions, there are significant repercussions for food and water security, as well as serious issues for the stability of broader social and environmental systems. To mitigate these effects, environmental monitoring and early warning systems aimed at detecting the onset of drought conditions can facilitate timely and effective responses from government and private sector stakeholders. This study uses multistage, participatory research methods across more than 135 interviews, focus groups, and workshops to assess extant climatic, agricultural, hydrological, and drought monitoring systems; key cross-sector drought impacts; and drought monitoring needs in four countries in the Middle East and North Africa (MENA) region: Morocco, Tunisia, Lebanon, and Jordan. This extensive study of user needs for drought monitoring across the MENA region is informing and shaping the ongoing development of drought early warning systems, a composite drought indicator (CDI), and wider drought management systems in each country. Overarching themes of drought monitoring needs include technical definitions of drought for policy purposes; information-sharing regimes and data-sharing platforms; ground-truthing of remotely sensed and modeled data; improved data quality in observation networks; and two-way engagement with farmers, organizations, and end-users of drought monitoring products. This research establishes a basis for informing enhanced drought monitoring and management in the countries, and the broad stakeholder engagement can help foster the emergence of effective environmental monitoring coalitions.

A key question in sustainable development is how much alteration in natural systems, such as river basins, is acceptable? One of the ways by which humans alter a river basin is by building water storage infrastructure. While storage reservoirs deliver numerous benefits, they can also induce social and environmental costs by displacing people, fragmenting river networks and altering downstream flow regimes. In such a context, merely capping total water withdrawal from rivers for human consumption is not sufficient. River basin plans should also identify optimal (acceptable) limits to surface storage capacities, and optimal numbers, degrees of distribution and locations of storage infrastructure. It remains largely unclear, however, whether it is possible to define a hydrologically, ecologically and socially justified ‘surface water storage boundary’ for a river basin. An associated question is what would be the ‘best’ arrangement of this bounding storage capacity in the basins river network (in terms of numbers, sizes and locations of reservoirs) to maximize water storage benefits and minimize environmental and social costs. The main objective of this review is to examine contemporary knowledge on surface water storage development with a focus on tools and approaches that may help to answer the above questions of a ‘surface water storage boundary’ and its ‘optimum arrangement’ for a river basin. In order to achieve this objective, our review introduces two novel concepts: the ‘storage scale’ and the ‘sustainable storage development framework.’ The ‘storage scale’ has four elements – capacity, number, distribution and location – individual scales that help visualize a ‘surface water storage boundary’ and its ‘optimum arrangement’ for a typical river basin. The ‘sustainable storage development framework’ consists of three dimensions – economic benefits, ecosystems and society- and a set of indicators quantifying each dimension. This review shows that optimal levels of the elements of the ‘storage scale’ may be identified using the ‘sustainable storage development framework’.

Understanding the spatiotemporal dynamics of surface water in varied, remote and inaccessible isolated floodplain lakes is difficult. Seasonal inundation patterns of these isolated lakes can be misestimated in a hydrodynamic model due to the short time of connectivity. The seasonal and annual variability of the Dinder River flow has great impact on what is so called Mayas wetlands, and hence, on the habitats and the ecological status of the Dinder National Park. This variability produces large morphological changes due to sediment transported within the river or from the upper catchment, which affects inflows to Mayas wetlands and floodplain inundation in general. In this paper, we investigated the morphological dimension using a quasi-3D modelling approach to support the management of the valuable Mayas wetlands ecosystems, and in particular, assessment of hydrological and morphological regime of the Dinder River as well as the Musa Maya. Six scenarios were developed and tested. The first three scenarios consider three different hydrologic conditions of average, wet and dry years under the existing system with the constructed connection canal. While the other three scenarios consider the same hydrologic conditions but under the natural system without an artificial connection canal. The modelling helps to understand the effect of human intervention (connection canal) on the Musa Maya. The comparison between the simulated scenarios concludes that the hydrodynamics and sedimentology of the Maya are driven by the two main factors: a) the hydrological variability of Dinder River; and b) deposited sediment plugs in the connection canal.

Many regions in Africa and the Middle East are vulnerable to drought and to water and food insecurity, motivating agency efforts such as the U.S. Agency for International Development’s (USAID) Famine Early Warning Systems Network (FEWS NET) to provide early warning of drought events in the region. Each year these warnings guide life-saving assistance that reaches millions of people. A new NASA multimodel, remote sensing–based hydrological forecasting and analysis system, NHyFAS, has been developed to support such efforts by improving the FEWS NET’s current early warning capabilities. NHyFAS derives its skill from two sources: (i) accurate initial conditions, as produced by an offline land modeling system through the application and/or assimilation of various satellite data (precipitation, soil moisture, and terrestrial water storage), and (ii) meteorological forcing data during the forecast period as produced by a state-of-the-art ocean–land–atmosphere forecast system. The land modeling framework used is the Land Information System (LIS), which employs a suite of land surface models, allowing multimodel ensembles and multiple data assimilation strategies to better estimate land surface conditions. An evaluation of NHyFAS shows that its 1–5-month hindcasts successfully capture known historic drought events, and it has improved skill over benchmark-type hindcasts. The system also benefits from strong collaboration with end-user partners in Africa and the Middle East, who provide insights on strategies to formulate and communicate early warning indicators to water and food security communities. The additional lead time provided by this system will increase the speed, accuracy, and efficacy of humanitarian disaster relief, helping to save lives and livelihoods.

Water security has emerged in the 21st century as a powerful construct to frame the water objectives and goals of human society and to support and guide local to global water policy and management. Water security can be described as the fundamental societal goal of water policy and management. This article reviews the concept of water security, explaining the differences between water security and other approaches used to conceptualize the water-related challenges facing society and ecosystems and describing some of the actions needed to achieve water security. Achieving water security requires addressing two fundamental challenges at all scales: enhancing water’s productive contributions to human and ecosystems’ well-being, livelihoods and development, and minimizing water’s destructive impacts on societies, economies, and ecosystems resulting, for example, from too much (flood), too little (drought) or poor quality (polluted) water.

Satellite-based actual evapotranspiration (ETa) is becoming increasingly reliable and available for various water management and agricultural applications from water budget studies to crop performance monitoring. The Operational Simplified Surface Energy Balance (SSEBop) model is currently used by the US Geological Survey (USGS) Famine Early Warning System Network (FEWS NET) to routinely produce and post multitemporal ETa and ETa anomalies online for drought monitoring and early warning purposes. Implementation of the global SSEBop using the Aqua satellite’s Moderate Resolution Imaging Spectroradiometer (MODIS) land surface temperature and global gridded weather datasets is presented. Evaluation of the SSEBop ETa data using 12 eddy covariance (EC) flux tower sites over six continents indicated reasonable performance in capturing seasonality with a correlation coefficient up to 0.87. However, the modeled ETa seemed to show regional biases whose natures and magnitudes require a comprehensive investigation using complete water budgets and more quality-controlled EC station datasets. While the absolute magnitude of SSEBop ETa would require a one-time bias correction for use in water budget studies to address local or regional conditions, the ETa anomalies can be used without further modifications for drought monitoring. All ETa products are freely available for download from the USGS FEWS NET website.

The managed aquifer recharge (MAR) of excess monsoonal runoff to mitigate downstream flooding and enhance groundwater storage has received limited attention across the Indo-Gangetic Plain of the Indian subcontinent. Here, we assess the performance of a pilot MAR trial carried out in the Ramganga basin in India. The pilot consisted of a battery of 10 recharge wells, each 24 to 30 m deep, installed in a formerly unused village pond situated adjacent to an irrigation canal that provided river water during the monsoon season. Over three years of pilot testing, volumes ranging from 26,000 to 62,000 m3 were recharged each year over durations ranging from 62 to 85 days. These volumes are equivalent to 1.3–3.6% of the total recharge in the village, and would be sufficient to irrigate 8 to 18 hectares of rabi season crop. High inter-year variation in performance was observed, with yearly average recharge rates ranging from 430 to 775 m3 day-1 (164–295 mm day-1 ) and overall average recharge rates of 580 m3 day-1 (221 mm day-1 ). High intra-year variation was also observed, with recharge rates at the end of recharge period reducing by 72%, 88% and 96% in 2016, 2017 and 2018 respectively, relative to the initial recharge rates. The observed inter- and intra-year variability is due to the groundwater levels that strongly influence gravity recharge heads and lateral groundwater flows, as well as the source water quality, which leads to clogging. The increase in groundwater levels in response to MAR was found to be limited due to the high specific yield and transmissivity of the alluvial aquifer, and, in all but one year, was difficult to distinguish from the overall groundwater level rise due to a range of confounding factors. The results from this study provide the first systematic, multi-year assessment of the performance of pilot-scale MAR harnessing village ponds in the intensively groundwater irrigated, flood prone, alluvial aquifers of the Indo-Gangetic Plain.

This chapter focuses on the linkages between climate change adaptation and disaster risk reduction, highlighting opportunities to build more resilient systems through a combination of apos;hardapos; and apos;softapos; measures.

Interventions that are robust, cost effective, and scalable are in critical demand throughout South Asia to offset growing water scarcity and avert increasingly frequent water-related disasters. This case study presents two complementary forms of intervention that transform water hazards (floodwater) into a resource (groundwater) to boost agricultural productivity and enhance livelihoods. The first intervention, holiya, is simple and operated by individual farmers at the plot/farm scale to control local flooding in semiarid climates. The second is the underground transfer of floods for irrigation (UTFI) and operates at the village scale to offset seasonal floods from upstream in humid climates. Rapid assessments indicate that holiyas have been established at more than 300 sites across two districts in North Gujarat since the 1990s, extending the crop growing season and improving water quality. UTFI knowledge and experience has grown rapidly since implementation of a pilot trial in western Uttar Pradesh in 2015 and is now embedded within government programs with commitments for modest scaling up. Both approaches can help farmers redress the multiple impacts associated with floods, droughts, and groundwater overexploitation at a range of scales from farm plot to the river basin. The potential for wider uptake across South Asia depends on setting up demonstration sites beyond India and overcoming gaps in technical knowledge and institutional capacity.

Soil moisture is a highly suitable indicator for assessing agricultural drought, as plants start to wilt when there is not sufficient soil water to meet evapotranspiration demand. In this study, we provide insights on information obtained from satellite surface soil moisture observations (as compared to modeled soil moisture and observed ground precipitation) on water stress and its impact on crop production variability in India. The analysis involved generating a Standardized Soil Moisture Index using (1) satellite soil moisture observations from the European Space Agency Climate Change Initiative and (2) the Modern-Era Retrospective Analysis for Research and Applications, version 2 soil moisture data set as well as producing a Standardized Precipitation Index using ground-based rainfall observations from the Indian Meteorological Department. Spanning the period from 1998 to 2015, the study covers Maharashtra and Karnataka states. These states were recently hit by a severe drought, resulting in significant crop failure and human losses. Results show that soil moisture is an important limiting factor for crop production. As such, it is more suitable for representing agricultural drought than precipitation during drought conditions, as it correlates more closely with reduced crop yields. Additionally, using the satellite-based Standardized Soil Moisture Index seemed to explain crop yield reductions better than when we applied the model-based Standardized Soil Moisture Index from Modern-Era Retrospective Analysis for Research and Applications, version 2, particularly for irrigated crops (i.e., wheat). This preliminary study can underpin future crop-forecasting tools assimilating satellite soil moisture data. In practice, satellite soil moisture may help to improve the efficiency of agricultural and irrigation management practices.

Protecting flood prone locations through floodwater recharge of the depleted aquifers and using it for protecting dry season irrigated agriculture is the rationale for a form of intervention termed as ‘underground transfer of floods for irrigation’ (UTFI). This helps reduce the intensity of seasonal floods by tapping and storing excess floodwater in aquifers for productive agricultural use. This paper presents a case study of managing the recharge interventions in the context of the Ramganga basin, India. Using a case study approach, this study determines the socio-economic and institutional context of the study area, proposes three potential routes to institutionalize UTFI, and provides insights for scaling up the interventions in the Ganges and other river basins that face seasonal floods and dry season water shortages. Managing the interventions involves community participation in regular operations and maintenance tasks. Given the limited scale of the pilot UTFI intervention implemented to date, and the socio-economic and institutional context of the case study region, the benefits are not conspicuous, though the piloting helped in identifying potential ways forward for the long-term management of the pilot site, and for scaling up the interventions. Initially pilot site management was handled by the project team working closely with the community leaders and villagers. As the intervention was demonstrated to perform effectively, management was handed over to the district authorities after providing appropriate training to the government personnel to manage the system and liaise with the local community to ensure the site is operated and managed appropriately. The district administration is willing to support UTFI by pooling money from different sources and routing them through the sub-district administration. While this is working in the short term, the paper outlines a programmatic longer term approach for wider replication.

The Ganga is an international transboundary river that flows across three major riparian countries: India, Nepal, and Bangladesh, where India shares a significant proportion of the total basin area. The river system is highly dynamic and regularly floods in all three countries due to abundant rainfall in a short period of only four months each year that causes tremendous loss of both property and human life. In this study, we have done a synoptic review to synthesize the hydrology, hydrogeology, and modeling studies that have analyzed hydrological changes and their impacts in the Ganga basin. This review also identifies some of the knowledge gaps and discusses possible options for enhancing the understanding of sustainable water development and management. This review indicated that transparent data sharing, use of satellite-based observations along with in-situ data, integrated hydro-economic modeling linked to reliable coupled surface–groundwater models, a central shared decision support center for early warning systems to deal with hydrological extremes, joint river commissions and monitoring teams, and multilateral water sharing treaties (agreements) are required to promote sustainable and equitable distribution of water resources and to avoid water sharing conflicts in the Ganga basin.

There is increasing recognition of the need to bring about changes across the full spectrum of agricultural practices to ensure that, in future, food production systems are more diverse, sustainable and resilient. In this context, the objectives of irrigation need to be much more ambitious, shifting away from simply maximizing crop yields to maximizing net benefits across a range of uses of irrigation water, including ecosystems and nature-based solutions. One important way to achieve this is by better integrating fisheries into the planning, design, construction, operation and management of irrigation systems. Irrigation – a major contributor to the Green Revolution – has significantly improved agricultural production worldwide, with consequent benefits for food security, livelihoods and poverty alleviation. Today, irrigated agriculture represents about 21 percent of cultivated land, but contributes approximately 40% of the total global crop production. Many governments continue to invest in irrigation as a cornerstone of food security and rural development. Investments in irrigation often represent a pragmatic form of adaptation to changing climatic conditions. This guide focuses on how to sustainably optimize and broaden the range of benefits from irrigation development - not only economic but also social and environmental benefits. It emphasizes the opportunities that fisheries could provide to increase food production and economic returns, enhance livelihoods and public health outcomes, and maintain key ecosystem services. The guide considers possible trade-offs between irrigation and fisheries, and provides recommendations on how these could be minimized.

This paper tries to shift the focus of research on the impact of natural disasters on economic growth from global and national levels to sub-national levels. Inadequate sub-national level information is a significant lacuna for planning spatially targeted climate change adaptation investments. A fixed-effect panel regression analyses of 19 states from 2001 to 2015 assess the impacts of exposure to floods and droughts on the growth of gross state domestic product (GSDP) and human development index (HDI) in India. The flood and drought exposure are estimated using satellite data. The 19 states comprise 95% of the population and contribute 93% to the national GDP. The results show that floods indeed expose a large area, but droughts have the most significant impacts at the sub-national level. The most affected GSDPs are in the non-agriculture sectors, positively by the floods and negatively by droughts. No significant influence on human development may be due to substantial investment on mitigation of flood and drought impacts and their influence on better income, health, and education conditions. Because some Indian states still have a large geographical area, profiling disasters impacts at even smaller sub-national units such as districts can lead to effective targeted mitigation and adaptation activities, reduce shocks, and accelerate income growth and human development.

As we rapidly modify the environment around us, researchers have a critical role to play in raising our understanding of the interactions between people and the world in which they live. Knowledge and understanding of these interactions are essential for evidence based decision-making on resource use and risk management. In this paper, we explore three research case studies that illustrate co-evolution between people and water systems. In each case study, we highlight how different knowledge and understanding, stemming from different disciplines, can be integrated by complementing narratives with a quantitative modelling approach. We identify several important research practices that must be taken into account when modelling people-water systems: transparency, grounding the model in sound theory, supporting it with the most robust data possible, communicating uncertainty, recognising that there is no ‘one true model’ and diversity in the modelling team. To support interdisciplinary research endeavours, we propose a three-point plan: (1) demonstrating and emphasising that interdisciplinary collaboration can both address existing research questions and identify new, previously unknown questions at the interface between the disciplines; (2) supporting individual interdisciplinary learning at all career stages and (3) developing group practices and a culture of interdisciplinary collaboration.

Floodplains are particularly important in the semi-arid region of the Sub-Sahelian Africa. In this region, water governance is still being developed, often without adequate information and technical capacity for good, sustainable water resource management. However, water resources are being allocated for use with minimal sustainability considerations. Environmental flows (e-flows) include the quantity and timing of flows or water levels needed to meet the sustainable requirements of freshwater and estuarine ecosystems. Holistic regional scale e-flows linked to floodplain management can make a noticeable contribution to sustainable floodplain management. The Inner Niger Delta (IND) in Mali is an example of a vulnerable, socio-ecologically important floodplain in the Sahel region of North Africa that is being developed with little understanding of sustainability requirements. Although integrally linked to the Upper Niger River catchment, the IND sustains a million and half people within the region and exports food to surrounding areas. The flooding of the Delta is the engine of the socio-economic development as well as its ecological integrity. This paper aims to demonstrate the contribution that holistic regional e-flow assessment using the PROBFLO approach has to achieving floodplain sustainability. This can be achieved through the determining the e-flow requirements to maintain critical requirements of the ecosystems and associated services used by local vulnerable human communities for subsistence and describing the socio-ecological consequences of altered flows. These outcomes can contribute to the management of the IND. In this study, the socio-ecological consequences of altered flows have been evaluated by assessing the risk of alterations in the volume, duration, and timing of flows, to a number of ecological and social endpoints. Based on the risk posed to these endpoints by each scenario of change, an e-flow of 58% (26,685 million cubic meters (MCM) of water annually) was determined that would protect the ecosystem and maintain indicator components at a sustainable level. These e-flows also provide sustainable services to local communities including products for subsistence and limit any abnormal increases in diseases to the vulnerable African communities who live in the basin. Relative risk outputs for the development scenarios result in low-to-high-risk probabilities for most endpoints. The future development scenarios include insufficient flows to maintain sustainability during dry or low-flow periods with an increase in zero flow possibilities. Although unsuitable during the low-flow or dry periods, sufficient water is available through storage in the basin to meet the e-flows if these scenarios were considered for implementation. The IND is more vulnerable to changes in flows compared to the rivers upstream of the IND. The e-flow outcomes and consequences of altered flow scenarios has contributed to the management of vulnerable IND f

South Africa is ranked among the thirty driest countries in the world, a challenge that is negatively affecting agricultural production. Other challenges such as population growth, rural-urban migration, changing food preferences and drought exacerbate pressure on agricultural water productivity. The review critically assessed the different considerations for increasing agricultural water productivity under water scarce conditions in South Africa. While under these conditions, irrigation may seem an obvious solution to increasing agricultural water productivity as a response to frequent droughts and mid-season dry spells. However, considerations on the availability of water and energy for irrigation expansion and the accessibility of irrigation services to different farming groups in the country. It is generally argued that irrigation is an expensive option and not necessarily readily accessible to most farmers. There are prospects for tapping into South Africa’s groundwater resources but the extent to which they can contribute to expanding area under irrigation is contested given the challenges of quantifying and pumping the water. Most smallholder farmers currently lack access to water, energy, infrastructure and technical skills to irrigate thus making irrigation a challenging option in this sector. An alternative would be to explore rainwater harvesting and soil water conservation technologies, which involve inducing, collecting, storing and conserving runoff water for agriculture. The drawbacks to this are that, apart from scale issues, rainfall is becoming more erratic and droughts more frequent and hence the feasibility of this approach under frequent drought could be challenged.

Food insecurity is a recurrent problem in northern Ghana. Food grown during the rainy season is often insufficient to meet household food needs, with some households experiencing severe food insecurity for up to five months in a year. Flood recession agriculture (FRA) – an agricultural practice that relies on residual soil moisture and nutrients left by receding flood water – is ordinarily practiced by farmers along the floodplains of the White Volta River in northern Ghana under low-input low-output conditions. Opportunities abound to promote highly productive FRA as a means of extending the growing season beyond the short rainy season (from May to September) into the dry season and thereby increase household income and food security of smallholder farmers. This study uses an optimization modelling approach to explore this potential by analyzing the crop mix and agricultural water management options that will maximize household income and enhance food security. Results indicate that growing cowpea, groundnut and melon under residual-moisture based FRA and high value crops (onion, pepper, and tomato) under supplementary irrigation FRA maximize household income and food security. The cash income from the sale of FRA crops was sufficient to purchase food items that ensure consumption smoothing during the food-insecure months. The study concludes that the full potential of FRA will be realized through a careful selection of crop mixtures and by enhancing access of farmers to improved seeds, integrated pest management and credit and mainstreaming FRA through targeted policy interventions and institutional support.

Southern Africa faces acute water scarcity challenges due to drought recurrence, degradation of surface water resources, and the increasing demand of water from agriculture, which has to meet the growing food demands of an increasing population. These stressors require innovative solutions that ensure the sustainability of water resources, without which the consequences could be dire for a region exposed to a host of vulnerabilities, including climate change. This review outlines the role of water markets in water management in times of water scarcity, highlighting the drivers of water markets in southern Africa, such as water scarcity, transboundary nature of water resources, and their uneven distribution. The review further discusses the role of water markets in climate change adaptation. Related institutional and legal frameworks as well as water allocation mechanisms are explored, aiming at improving water markets governance. The impact of adaptation to new water regimes in the face of scarcity are assessed by considering characteristics of current markets as related to future opportunities. In a diverse region such as southern Africa with unevenly distributed water resources, advancing the concept of water markets could play an important role in mitigating water scarcity challenges and promoting regional integration through coordinated transboundary water transfers. The emergence of water markets in the region is influenced by the continued depletion of water resources, which is resulting in the adoption of innovative water marketing strategies, such as inter-farm sharing or farm joint venture systems and inter-basin and intra-basin water transfers. As the concept is new in the region, it still has challenges that include general market inefficiencies, high transaction costs, market information asymmetries, imperfect competition, and weak or absent robust institutional frameworks that can facilitate market development.

This report presents findings from a study conducted to explore the synergies and trade-offs between built (i.e., engineered) and natural (i.e., ecological systems) infrastructure in the Tana River Basin, Kenya. The study considered hydrological, ecological and economic processes in order to value flow-related ecosystem services. It provides quantitative insights into the links between flow and the benefits derived from both built and natural infrastructure. The results provide initial perspectives not just on the monetary values of a number of ecosystem services (and how they change as flows vary and are altered by large dams) but also, importantly, aspects of equity and social inclusion, that also need to be considered in decision-making.

The impact of climate variability on groundwater storage has received limited attention despite widespread dependence on groundwater as a resource for drinking water, agriculture and industry. Here, we assess the climate anomalies that occurred over Southern Africa (SA) and East Africa, south of the Equator (EASE), during the major El Nio event of 2015–2016, and their associated impacts on groundwater storage, across scales, through analysis of in situ groundwater piezometry and Gravity Recovery and Climate Experiment (GRACE) satellite data. At the continental scale, the El Nio of 2015–2016 was associated with a pronounced dipole of opposing rainfall anomalies over EASE and Southern Africa, north–south of ~12 S, a characteristic pattern of the El Nio–Southern Oscillation (ENSO). Over Southern Africa the most intense drought event in the historical record occurred, based on an analysis of the cross-scale areal intensity of surface water balance anomalies (as represented by the standardised precipitation evapotranspiration index – SPEI), with an estimated return period of at least 200 years and a best estimate of 260 years. Climate risks are changing, and we estimate that anthropogenic warming only (ignoring changes to other climate variables, e.g. precipitation) has approximately doubled the risk of such an extreme SPEI drought event. These surface water balance deficits suppressed groundwater recharge, leading to a substantial groundwater storage decline indicated by both GRACE satellite and piezometric data in the Limpopo basin. Conversely, over EASE during the 2015–2016 El Nio event, anomalously wet conditions were observed with an estimated return period of ~10 years, likely moderated by the absence of a strongly positive Indian Ocean zonal mode phase. The strong but not extreme rainy season increased groundwater storage, as shown by satellite GRACE data and rising groundwater levels observed at a site in central Tanzania. We note substantial uncertainties in separating groundwater from total water storage in GRACE data and show that consistency between GRACE and piezometric estimates of groundwater storage is apparent when spatial averaging scales are comparable. These results have implications for sustainable and climate-resilient groundwater resource management, including the potential for adaptive strategies, such as managed aquifer recharge during episodic recharge events.

Indian agricultural communities are facing a crisis driven by, among other things, skewed terms of trade and farmers’ inability to deal with increasingly adverse climatic conditions. Because agriculture continues to be the primary source of livelihood for most of India’s population, governments at all levels are under pressure to find ways to help farmers. In western and peninsular India, where droughts are common, several state governments have vowed to make farming “drought-proof” through ambitious flagship programs. This case study reviews the experience of four such programs in Gujarat, Maharashtra, Telangana, and Rajasthan. Although the programs differ in approach, implementation style, and duration, all of them aim to shield farmers, particularly smallholders, from the misery imposed by droughts. Among these states, efforts in Gujarat appear to be the most mature; however, concerns regarding sustaining momentum, capacity building of communities, demand management, and establishing functional local governance remain. We use evidence gathered through field studies to draw lessons for designing effective drought-mitigation strategies through improved management of groundwater resources.

Southern Africa is highly vulnerable to drought because of its dependence on climate-sensitive sectors of agriculture, hydroenergy and fisheries. Recurring droughts continue to impact rural livelihoods and degrade the environment. Drought severity in southern Africa is exacerbated by poor levels of preparedness and low adaptive capacity. Whilst weather extremes and hazards are inevitable, the preparedness to manage such hazards determines their impact and whether they become disasters. Southern Africa is often caught unprepared by drought as existing early warning systems lack the drought forecasting component, which often results in reactionary interventions as opposed to well-planned and proactive response mechanisms. This study assesses the spatio-temporal changes of rainfall and aridity in southern Africa through an analysis of long-term precipitation and evaporation trends from 1960 to 2007. Stakeholder consultation was conducted in Madagascar, Malawi, Zambia and Zimbabwe during the peak of the 2015/16 drought, focusing on overall drought impacts, current water resource availability, existing early warning systems, adaptation mechanisms and institutional capacity to mitigate and manage droughts as part of overall disaster risk reduction strategies. Average rainfall has decreased by 26% in the region between 1960 and 2007, and aridity has increased by 11% between 1980 and 2007. The absence of drought forecasting and lack of institutional capacity to mitigate drought impede regional drought risk reduction initiatives. Existing multi-hazard early warning systems in the region focus on flooding and drought monitoring and assessment. Drought forecasting is often not given due consideration, yet it is a key component of early warning and resilience building. We propose a regional drought early warning framework, emphasising the importance of both monitoring and forecasting as being integral to a drought early warning system and building resilience to drought.

The increasing frequency and intensity of droughts and floods, coupled with increasing temperatures and declining rainfall totals, are exacerbating existing vulnerabilities in southern Africa. Agriculture is the most affected sector as 95% of cultivated area is rainfed. This review addressed trends in moisture stress and the impacts on crop production, highlighting adaptation possible strategies to ensure food security in southern Africa. Notable changes in rainfall patterns and deficiencies in soil moisture are estimated and discussed, as well as the impact of rainfall variability on crop production and proposed adaptation strategies in agriculture. Climate moisture index (CMI) was used to assess aridity levels. Southern Africa is described as a climate hotspot due to increasing aridity, low adaptive capacity, underdevelopment and marginalisation. Although crop yields have been increasing due to increases in irrigated area and use of improved seed varieties, they have not been able to meet the food requirements of a growing population, compromising regional food security targets. Most countries in the region depend on international aid to supplement yield deficits. The recurrence of droughts caused by the El Nio Southern Oscillation (ENSO) continue devastating the region, affecting livelihoods, economies and the environment. An example is the 2015/2016 ENSO drought that caused the region to call for international aid to feed about 40 million people. In spite of the water scarcity challenges, cereal production continues to increase steadily due to increased investment in irrigated agriculture and improved crop varieties. Given the current and future vulnerability of the agriculture sector in southern Africa, proactive adaptation interventions are important to help farming communities develop resilient systems to adapt to the changes and variability in climate and other stressors.

The flood-based farming systems in the Ayeyarwady Delta in Myanmar are changing. Change describes the modification of the flood pattern which is constituted by depth and duration of flooding and is the determining factor for rice cultivation. Flood-induced crop loss poses the major challenge to the farmers in the delta. To understand the flood-based farming systems in the Ayeyarwady Delta, the random forest algorithm was applied to generate rice suitability location models and to create suitability maps. Thus, correlations were observed between the developed definitions for the three rice growing areas based on quantitative interviews with farmers and the physical factors obtained from the input datasets – mainly remote sensing data concerning surface water and vegetation. To underpin the information of the generated suitability maps, human-water dynamics in the Ayeyarwady Delta are exemplified in terms of the pluralistic water research (PWR) framework (EVERS ET AL. 2017). Socio-economic and hydro-climatic drivers control this system and besides determine the suitable location of the three rice growing areas. This concept facilitates an understanding of the relationships and feedbacks of the human-water dynamics and is able to analyse flood risk mitigation in the Ayeyarwady Delta.

This report builds on prior work to provide a new, comprehensive, and balanced view of water security in Pakistan, stressing the importance of the diverse social, environmental, and economic outcomes from water. The report highlights the complex water issues that Pakistan must tackle to improve water security and sheds new light on conventional assumptions around water. It seeks to elevate water security as an issue critical for national development. The report assesses current water security and identifies important water-related challenges that may hinder progress in economic and human development. It identifies unmitigated water-related risks, as well as opportunities where water can contribute to economic growth and poverty reduction. The report analyzes how the performance and architecture of the water sector are related to broader economic, social, and environmental outcomes. It models alternative economic trajectories to identify where intervention can lead to a more water-secure future. A consideration of water sector architecture and performance and how these determine outcome leads to recommendations for improving aspects of sector performance and adjusting sector architecture for better outcomes. The sector performance analysis considers (a) management of the water resource, (b) delivery of water services, and (c) mitigation of water-related risks. The description of sector architecture considers water governance, infrastructure, and financing.

Himalayan river basin is marked by a complex topography with limited observational data. In the context of increasing extreme events, this study aims to characterize drought events in the Karnali River Basin (KRB). Firstly, historical data for 34-years (1981–2014) from ten different stations were analyzed to compute following drought indices: Standardized Precipitation Index (SPI), Standardized Precipitation Evapotranspiration Index (SPEI), Reconnaissance Drought Index (RDI), Self-Calibrated Palmer Drought Severity Index (sc-PDSI), Standardized Streamflow Index (SFI), and Palmer Hydrological Drought Severity Index (PHDI). Among them, SPI is able to capture the drought duration and intensity fairly well with the others. Secondly, SPI was used to analyse the drought of the entire basin. The SPI analysis showed occurrence of major drought events in the recent years: 1984–85, 1987–88, 1992–93, 1994–95, 2004–09, and 2012. The winter drought of 1999, 2006, 2008–09 were widespread and the monsoon drought is increasing its frequency. No particular pattern of drought was observed from the historical data; however, yield sensitivity index revealed that precipitation pattern and anomaly is influencing crop yield in the area. Being the first study revealing prevalence of the drought in KRB, it can provide a basis for prioritizing interventions focused on drought management in the region.

The Himalayas are highly susceptible to the impacts of climate change, as it consequently increases the vulnerability of downstream communities, livelihoods and ecosystems. Western Nepal currently holds significant potential as multiple opportunities for water development within the country are underway. However, it is also identified as one of the most vulnerable regions to climate change, with both an increase in the occurrence of natural disasters and exacerbated severity and impacts levels. Regional climate model (RCM) projections indicate warmer weather with higher variability in rainfall for this region. This paper combines bio-physical and social approaches to further study and understand the current climate shocks and responses present in Western Nepal. Data was collected from 3660 households across 122 primary sampling units across the Karnali, Mahakali and Mohana River basins along with focus group discussions, which provided a rich understanding of the currently perceived climatic shocks and related events. Further analysis of climatology was carried out through nine indices of precipitation and temperature that were found to be relevant to the discussed climate shocks. Results show that 79% of households reported experiencing at least one type of climate shock in the five-year period and the most common occurrence was droughts, which is also supported by the climate data. Disaggregated results show that perception varies with the region and among the basins. Analysis of climatic trends further show that irregular weather is most common in the hill region, although average reported frequency of irregular weather is higher in the mountain. Further analysis into the severity and response to climatic shocks suggest an imminent need for better adaptation strategies. This study’s results show that a vast majority of respondents lack proper access to knowledge and that successful adaptation strategies must be adapted to specific regions to meet communities’ local needs.

Climate variability and change impacts are manifesting through declining rainfall totals and increasing frequency and intensity of droughts, floods and heatwaves. These environmental changes are affecting mostly rural populations in developing countries due to low adaptive capacity and high reliance on natural systems for their livelihoods. While broad adaptation strategies exist, there is need to contextualise them to local scale. This paper assessed rainfall, temperature and water stress trends over time in Capricorn District, South Africa, using Standardized Precipitation Index, Thermal Heat Index, and Normalised Difference Vegetation Index (NDVI) as a proxy of water stress. Observed rainfall and temperature data from 1960 to 2015 was used to assess climatic variations, and NDVI was used to assess water stress from 2000 to 2019. Results show a marked increase in drought frequency and intensity, decreasing rainfall totals accompanied by increasing temperatures, and increasing water stress during the summer season. Long-term climatic changes are a basis to develop tailor-made adaptation strategies. Eighty-one percent of the cropped area in Capricorn District is rainfed and under smallholder farming, exposing the district to climate change risks. As the intensity of climate change varies both in space and time, adaptation strategies also vary depending on exposure and intensity. A combination of observed and remotely sensed climatic data is vital in developing tailor-made adaptation strategies.

Floods account for a majority of disasters, especially in South Asia, where they affect 27 million people annually, causing economic losses of over US$1 billion. Climate change threatens to exacerbate these risks. Risk transfer mechanisms, such as weather index insurance (WII) may help buffer farmers against these hazards. However, WII programs struggle to attract the clients most in need of protection, including marginalized women and men. This risks re-enforcing existing inequalities and missing opportunities to promote pro-poor and gender-sensitive development. Key questions, therefore, include what factors constrain access to WIIs amongst heterogeneous communities, and how these can be addressed. This paper contributes to that end through primary data from two WII case studies (one in India, the other in Bangladesh) that identify contextual socio-economic and structural barriers to accessing WII, and strategies to overcome these. More significantly, this paper synthesizes the case study findings and those from a review of the literature on other WII initiatives into a framework to promote a systematic approach to address these challenges: an important step forward in moving from problem analysis to remedial action. The framework highlights actions across WII product design, implementation and post-implementation, to minimize risks of social exclusion in future WII schemes.

Groundwater quantity and quality may be affected by climate change through intricate direct and indirect mechanisms. At the same time, population growth and rapid urbanization have made groundwater an increasingly important source of water for multiple uses around the world, including southern Africa. The present study investigates the coupled human and natural system (CHANS) linking climate, sanitation, and groundwater quality in Ramotswa, a rapidly growing peri-urban area in the semi-arid southeastern Botswana, which relies on the transboundary Ramotswa aquifer for water supply. Analysis of long-term rainfall records indicated that droughts like the one in 2013–2016 are increasing in likelihood in the area due to climate change. Key informant interviews showed that due to the drought, people increasingly used pit latrines rather than flush toilets. Nitrate, fecal coliforms, and caffeine analyses of Ramotswa groundwater revealed that human waste leaching from pit latrines is the likely source of nitrate pollution. The results in conjunction indicate critical indirect linkages between climate change, sanitation, groundwater quality, and water security in the area. Improved sanitation, groundwater protection and remediation, and local water treatment would enhance reliable access to water, de-couple the community from reliance on surface water and associated water shortage risks, and help prevent transboundary tension over the shared aquifer.

Drought is a noteworthy cause of low agricultural profitability and of crop production vulnerability, yet in numerous countries of Africa little to no consideration has been paid to readiness for drought calamity, particularly to spatial evaluation and indicators of drought occurrence. In this study, biophysical and socio-economic data, farmers’ community surveys and secondary data from remote sensing on soil characteristics and water demand were used to evaluate the predictors of drought in inland valley rice-based production systems and the factors affecting farmers’ mitigation measures. The study intervened in three West African countries located in the Sudan-Sahel zone, viz. Burkina Faso, Mali and Nigeria. Significant drying trends occurred at latitudes below 1130apos; whilst significant wetting trends were discerned at latitude above 1130apos;. Droughts were more frequent and had their longest duration in the states of Niger and Kaduna located in Nigeria and in western Burkina Faso during the period 1995–2014. Among 21 candidate predictors, average annual standardized precipitation evapotranspiration index and duration of groundwater availability were the most important predictors of drought occurrence in inland valleys rice based-production systems. Land ownership and gender affected the commitment of rice farmers to use any mitigation measure against drought. Drought studies in inland valleys should include climatic water balance and groundwater data. Securing property rights and focusing on women’s association would improve farmers’ resilience and advance drought mitigation measures.

In the Ganges basin, 8268.6 km2 of irrigation command area is waterlogged following monsoon rains. In this study, vertical drain (VD) (L × D, 7 × 1 m) filled with drainage gravel (6.5 m) and coarse sand (0.5 m) is installed in farmer’s agricultural field to minimize the duration of seasonal waterlogging and tested in Mukundpur village, Vaishalli District, Bihar, India. At the experimental site, inundation of rainfall and runoff from surrounding areas along with the seepage from an earthen canal start in September and remain till February, every year which prevents timely planting of wheat in November-end/December. Drainage due to percolation and recharge to groundwater is constrained by 6.4-m thick clay layer, below 0.5-m root-zone, and the groundwater level, which rises to the surface level. VDs were installed to provide a path and allow inundated water to recharge the aquifer, as groundwater level recedes. Groundwater level drop, floodwater infiltration rate, groundwater discharge, and VD capability were estimated through field data. Results show that VDs connected the floodwater to groundwater and transferred the floodwater to the aquifer when groundwater level started to recede. The site was fully drained by the end of December, permitting farmers to plant wheat in January providing cool nights at germination, thus increasing yields.

Groundwater use in India, and many developing countries, is linked to livelihood and well-being of village communities. It is, therefore, important to characterise groundwater behaviour and resilience and identify strategies that will help to improve the sustainability of groundwater supplies. The concept of Standardised Precipitation Index (SPI) has been widely used for analysing rainfall drought. In this study, we adapt SPI to understand watertable fluctuations and assess resilience of groundwater supplies vis--vis rainfall variability from one year to the next. The modified SPI, called Groundwater Resilience Index (GRI), represents a normalized continuous watertable elevation variability function. The index is applied to two districts, viz., Udaipur and Aravalli in Rajasthan and Gujarat, India, respectively, to assess its usefulness. To evaluate the association of rainfall variability with groundwater depth fluctuation, SPI was also calculated. The study showed that GRI varies less than SPI, indicating that groundwater availability is less variable than the rainfall in both districts. This means that groundwater increases reliability of water supply for irrigation in both districts. The estimated SPI and GRI at 6-month intervals for the study period show that even though the groundwater is not stressed (normal condition in 75% of the months observed), there is variation in resilience of the aquifer system to drought and extreme events. Overall, the study indicated that the proposed GRI can be a useful tool for understanding watertable fluctuations and assessing groundwater resilience, especially to prioritise areas for groundwater recharge when funds for recharge works are limited.

After a hiatus through the 1990s and the early part of this century, rising energy demand, new private sector financing options and countries pursuing food security, modernization and economic growth have spurred a new era of large dam development. Currently an estimated 3700 dams are planned or under construction globally (Zarfl et al., [2015] 77, 161–170). Many of the challenges faced in the context of the water-energy-food nexus are brought into sharp focus by large dam construction. Dams can safeguard food production, provide an important source of income and relatively cheap electricity, and can have direct and indirect benefits for poor people. Too often, however, they have created significant and poorly mitigated environmental and social costs (WCD, [2000] London: Earthscan Publications Ltd). Adverse impacts on ecosystem services caused by dam construction can have profound implications for the health, resilience and livelihoods of the poor. This article explores the challenges facing decision makers with regards to building resilience and navigating risk within the water-energy-food nexus and dams. It draws from two progressive case studies, one in Africa and one in Asia, to highlight lessons learned from nexus approaches including the need for meaningful participation, transparency in decision making, and valuing ecosystem services. The case studies examined contain relevant lessons for global agreements including the Sustainable Development Goals and the Paris Agreement because unlike the Millennium Development Goals, they are expected to address interlinkages and tradeoffs across the nexus. The implications of the increasing trend of public private partnerships to finance, build, and operate hydropower dams is discussed. The article concludes by demonstrating that although mitigating impacts across the nexus and social-ecological resilience presents challenges and requires overcoming complexity, the need to tackle these is greater than ever.

Critical information on a flood-affected area is needed in a short time frame to initiate rapid response operations and develop long-term flood management strategies. This study combined rainfall trend analysis using Asian Precipitation—Highly Resolved Observational Data Integration towards Evaluation of Water Resources (APHRODITE) gridded rainfall data with flood maps derived from Synthetic Aperture Radar (SAR) and multispectral satellite to arrive at holistic spatio-temporal patterns of floods in Sri Lanka. Advanced Land Observing Satellite Phased Array type L-band Synthetic Aperture Radar (ALOS PALSAR) data were used to map flood extents for emergency relief operations while eight-day Moderate Resolution Imaging Spectroradiometer (MODIS) surface reflectance data for the time period from 2001 to 2016 were used to map long term flood-affected areas. The inundation maps produced for rapid response were published within three hours upon the availability of satellite imagery in web platforms, with the aim of supporting a wide range of stakeholders in emergency response and flood relief operations. The aggregated time series of flood extents mapped using MODIS data were used to develop a flood occurrence map (2001–2016) for Sri Lanka. Flood hotpots identified using both optical and synthetic aperture average of 325 km2 for the years 2006–2015 and exceptional flooding in 2016 with inundation extent of approximately 1400 km2. The time series rainfall data explains increasing trend in the extreme rainfall indices with similar observation derived from satellite imagery. The results demonstrate the feasibility of using multi-sensor flood mapping approaches, which will aid Disaster Management Center (DMC) and other multi-lateral agencies involved in managing rapid response operations and preparing mitigation measures.

Climate induced extreme events such as floods and droughts are often disastrous in incidences and affects Indian economy often. Low per capita surface water storage (225 m3/capita1), few sites for additional storages facilities and depleting groundwater aquifers reduce the resilience of the communities to alleviate the day-to-day short age and larger seasonal shocks. India has a long history of storing and recharging runoff waters through community participation. Ongoing such programs are focused on drought-prone or socio-economically weak areas and exclude the flood prone zones. The present study aims to improve the groundwater resources availability through diverting flows from rivers or canals at times when these flows pose flood risk and recharging the groundwater through suitable artificial recharge structures. This method addresses the issue of groundwater depletion as well as reducing the flood risks. A geo-hydrological analysis in spatial platform using data available in public domain and detailed ground survey, a site was identified in Jiwai Jadid village of Milk Block of Rampur district of Uttar Pradesh, India. A community owned pond was retrofitted with recharge wells and associated infrastructure to draw excess monsoon water from a nearby flood-prone river. The preliminary results show a positive impact on groundwater table and water quality. However, to achieve the full benefit of the method it is required to implement it in larger scale. Ongoing government programs that are focused on livelihood improvement and natural resources management are the best options to scale up such effect in regional scale.

Underground taming of floods for irrigation (UTFI) is a new approach for mitigating flood impacts through targeted floodwater storage in depleted aquifers for irrigating crops in the dry season. UTFI not only fosters the much desired conjunctive use and management of water resources but also provides the environmental services that are of high socioeconomic value. UTFI interventions are individually established at the local scale (e.g. village pond, check dam) but to achieve more substantial positive benefits at the scale of meso watersheds (10 s of km2) or sub-basins (100–1,000 s of km2) in the flood-prone river basins requires area-based implementation. Given the nature and scale required, UTFI needs to be managed at the community level with the help of appropriate institutional arrangements taking into account both the upstream and downstream locations. This paper reviews the existing institutional approaches and proposes an institutional framework that can help to mainstream UTFI management in the context of South Asia. The proposed model is centred on the existing formal institutions and also integrates non-market (participatory) and market (payment for ecosystem services) instruments that can provide win–win strategies for water resource management to downstream and upstream communities.

Capturing inundation extent by floods is indispensable for decision making for mitigating hazard. Satellite images have commonly been used for flood mapping, but there are limitations such as unavailability due to satellite’s orbital period or cloud cover. Additionally, it would also be beneficial for policy makers to figure out the impact of water management measures such as water storage options on flood mitigation and irrigation water strengthening. Utilization of flood inundation models would support providing information for these demands. In this study, the rainfall–runoff inundation (RRI) model was applied in a flood-prone basin in eastern Sri Lanka, and its applicability was discussed. The RRI model was capable of simulating discharge and inundation extent during flood events, although it should be noted that the model had been calibrated targeting only the flooding period. Satellite-observed rainfall data corrected with a scale factor were able to be used as the model input to simulate long-term trends in runoff just as well as when gauged rainfall data were applied. The calibrated model was also capable of evaluating flood mitigation effects of existing and proposed water storage options by simulating discharge with and without flood capture operations. By reproducing long-term inflow to the storage facilities using satellite rainfall data, it was possible to determine that water would reach the maximum level of the proposed storage facilities even during low-rainfall years.

In the Gash Delta of Eastern Sudan, spate irrigation (flood-recession farming) contributes substantially to rural livelihoods by providing better yields than rainfed dryland farming. However, spate irrigation farmers are challenged by the unpredictability of flooding. In recent decades, the number of farmers practicing spate irrigation has decreased, due to varying rainfall intensity and frequency, insufficient infrastructure and farmers’ limited capacity to manage such variations. One solution that may help farmers face such challenges is for them to access real-time water-related information by using smart Information and Communication a Technology (ICT). This paper shows how integrating remote sensing, Geographical Information Systems (GIS), flood-forecasting models and communication platforms can, in near real time, alert smallholder farmers and relevant government departments about incoming floods, using the Gash basin of Sudan as an example. The Ministry of Water Resources of Sudan used the findings of this study to transform farmers’ responses to flood arrival from being ‘reactive’, to planning for the flood event. Intensive on-site and institutional efforts to build the capacity of farmers, farmer organizations, development departments and officers of the Ministry helped to develop the initiative from simply sending ‘emergency alerts’ to enabling stakeholders to visually see the flood event unfolding in the region and to plan accordingly for storing water, operating spate-irrigation systems and undertaking cropping activities. The research, initially conducted on a 60 × 60 km site, was later extended to the entire Gash basin. The paper outlines how to develop tools that can monitor plot-specific information from satellite measurements, and supply detailed and specific information on crops, rather than providing very general statements on crop growth. Farmers are able to use such tools to optimize their farm profits by providing water to their crops in the right place, at the right time and in the right quantity. Finally, the work demonstrates the high potential of combining technology, namely remote sensing data and simple a agro-meteorological model with limited parameters, for large-scale monitoring of spate irrigation systems and information sharing to advise farmers as to how to apply this information to their managerial decisions.

The Ganges basin faces considerable spatial and temporal imbalance between water demand and availability. Lack of water storage infrastructure has led to this mismatch, wherein there are limited options to store flood water during the wet season and limited groundwater and surface water resources during the dry season. In this current study, a semi-coupled hydrological modeling framework is used to test scenarios that can help bridge this imbalance. A hydrological model (SWAT), groundwater model (MODFLOW) and flood inundation model (HEC-RAS) were applied to the Ramganga basin in India (*19,000 km2) to understand the baseline hydrologic regime and to test scenarios with distributed managed aquifer recharge (MAR) interventions, which when applied to at the basin scale to co-address flooding and groundwater depletion has come to be known as Underground Taming of Floods for Irrigation. The scenarios with MAR, which used available basin runoff to recharge groundwater, yielded favorable results in flood reduction and groundwater level improvement throughout the sub-basin. Groundwater levels improved within 5 years of introducing MAR, resulting in a groundwater elevation increase of up to 7 mwhen compared to baseline conditions. The HEC-RAS model indicated that a 20% reduction in basin outflow converted a 15-year flood peak to an 8-year flood peak, a 5-year peak to 3 years and a 2-year peak to 1 year. In addition, this resulted in a 10% reduction in the inundated area in all return periods tested. Therefore, distributed MAR practices can be effective in reducing the negative impacts from larger return period floods and increasing the groundwater levels.

The performance of Satellite Rainfall Estimate (SRE) products applied to flood inundation modelling was tested for the Mundeni Aru River Basin in eastern Sri Lanka. Three SREs (PERSIANN, TRMM, and GSMaP) were tested, with the Rainfall-Runoff-Inundation (RRI) model used as the flood inundation model. All the SREs were found to be suitable for applying to the RRI model. The simulations created by applying the SREs were generally accurate, although there were some discrepancies in discharge due to differing precipitation volumes. The volumes of precipitation of the SREs tended to be smaller than those of the gauged data, but using a scale factor to correct this improved the simulations. In particular, the SRE, i.e., the GSMaP yielding the best simulation that correlated most closely with the flood inundation extent from the satellite data, was considered the most appropriate to apply to the model calculation. The application procedures and suggestions shown in this study could help authorities to make better-informed decisions when giving early flood warnings and making rapid flood forecasts, especially in areas where in-situ observations are limited.

The Kalu Ganga Basin in Sri Lanka is generally flooded once a year. A network of low-lying lands acts as natural retention and storage that captures floodwater, minimizing damage. An increase in the flood frequency has been observed in recent years. It is commonly perceived that this increase is caused by a rise in the frequency and severity of ‘very wet’ precipitation events. We conclude that land-use changes may have played a larger role in generating floods.

limatic and hydrological changes will likely be intensified in the Upper Blue Nile (UBN) basin by the effects of global warming. The extent of such effects for representative concentration pathways (RCP) climate scenarios is unknown. We evaluated projected changes in rainfall and evapotranspiration and related impacts on water availability in the UBN under the RCP4.5 scenario. We used dynamically downscaled outputs from six global circulation models (GCMs) with unprecedented spatial resolution for the UBN. Systematic errors of these outputs were corrected and followed by runoff modelling by the HBV (Hydrologiska ByrnsVattenbalansavdelning) model, which was successfully validated for 17 catchments. Results show that the UBN annual rainfall amount will change by -2.8 to 2.7% with a likely increase in annual potential evapotranspiration (in 2041–2070) for the RCP4.5 scenario. These changes are season dependent and will result in a likely decline in streamflow and an increase in soil moisture deficit in the basin.

The Bhungroo Irrigation Technology (BIT) is a system designed to infiltrate excess ‘standing’ floodwater to be stored underground and abstracted for irrigation during the dry season. The system was developed in India and piloted in three sites in northern Ghana. This paper documents the implementation of BIT, the operating principles and criteria for selecting appropriate sites for the installation of such systems, as well as the potential benefits complementing existing irrigation systems in Ghana. Essential requirements for the installation of BIT include biophysical features such as land-use type, soil type, surface hydrology and slope of the terrain. The hydrogeological characteristics of the subsoil are also vital, and must exhibit high storage capacity and potential for groundwater accessibility. To be profitable and generate benefits for farmers, the technology needs to be situated in close proximity to markets and must have public acceptance.

Co-composted dewatered faecal sludge (FS) with organic fractions of municipal solid waste (MSW) has a high potential to be used as an agricultural resource in Sri Lanka. In addition to options for cost recovery in waste management, closing the nutrient and carbon cycles between urban and rural areas, substitution of mineral fertilizers, reduced pollution. and the restoration of degraded arable land are possible with important benefits. Up to now little is known about the usage of FS-MSW as fertilizer and it needs to be studied in order to achieve a better understanding and generate application recommendations. The aim of these experiments has been to evaluate the possibility of substituting mineral fertilization. Two field experiments were conducted on sandy loam to assess the effects of MSW compost and FS-MSW co-compost, its pelletized forms, and mineral-enriched FS-MSW on crop growth. As a short-term crop Raphanus sativus “Beeralu rabu” (radish) was studied for 50 days in a randomized complete block design (RCDB). Results show that, under drought conditions, FS-MSW co-compost increased the yield significantly, while MSW and FS-MSW compost enabled the highest survival rate of the plants. Similarly, the second field trial with a long-term crop, Capsicum anuum “CA-8” (capsicum), was planted as RCBD, using the same treatments, for a cultivation period of 120 days. Results display that during a drought followed by water saturated soil conditions co-compost treatments achieved comparable yields and increased the survival rate significantly compared to the control, fertilized with urea, triple super phosphate, and muriate of potash. Cost-benefit analysis (CBA) revealed that pelletizing decreased the monetary benefits if only fertilizer value is considered. It can be concluded that, under drought and water stress, co-compost ensures comparable yields and enables more resistance, but might not be economical viable as a one-crop fertilizer. These findings need to be validated with further trials under different climate regimes and soils.

This Research Report presents the first comprehensive overview of the multiple climate hazard risks, and the proposed key issues and challenges facing the South Asian region. This report suggests methods for mapping such risks and estimating their impacts on people and agriculture in South Asia. Regional, country-wise and sub-national assessment of five climate-related risks – floods, droughts, extreme rainfall, extreme temperature and sea-level rise – is carried out. The approach involves overlaying climate hazard, sensitivity and adaptive capacity maps, and follows the vulnerability assessment framework of the Intergovernmental Panel on Climate Change (IPCC). A combined index based on hazard, exposure and adaptive capacity is introduced to identify areas susceptible to extreme risk. There is a lack of a systematic and comprehensive risk assessment capturing multiple climate hazards for the entire South Asian region and the need for a common framework for risk assessment. While this approach is well grounded in theories and integration of various spatial data including remote sensing data to derive hazard information, there is a clear need for linking additional elements from the ground at a finer scale among various sectors in developing comprehensive risk assessment information for a disaster risk management plan and promoting risk financing strategies.

Storing excess rainwater underground can become key in mitigating the frequency and magnitude of flood events. In this context, assessment of depleted groundwater storage that can be refilled in water surplus periods is imperative. The study uses Gravity Recovery and Climate Experiment (GRACE) data to identify variations in groundwater storage in the monsoonal Ramganga River basin (tributary of the Ganges, with an area of 32,753 km2) in India, over the nine-year period of 2002–2010. Results indicate that basin groundwater storage is depleting at the rate of 1.6 bill. m3 yr 1 . This depleted aquifer volume can be used to store floodwater effectively – up to 76% of the rainfall on average across the Ramganga with a maximum of 94% in parts of the basin. However, the major management challenge is to find and introduce technical and policy interventions to augment recharge rates to capture excess water, at required scales.

Achieving water security has emerged as a major objective in Africa, yet an analytical or diagnostic framework for assessing water security in African countries is not known to exist. This paper applies one key dimension of the 2016 Asian Development Bankapos;s (ADB) Asian Water Development Outlook (AWDO) to assess levels of water security for productive economies in countries of the Southern African Development Community (SADC). Economic aspects of water security cover four areas: economic activities in the broad sense, agriculture, electricity, and industry. Water security in each area is measured through application of a set of indicators; results of indicator application are then aggregated to determine economic water security at a country-level. Results show that economic water security in SADC is greatest in the Seychelles and South Africa, and lowest in Madagascar and Malawi. Opportunities for strengthening economic water security in the majority of SADC countries exist through improving agricultural water productivity, strengthening resilience, and expanding sustainable electricity generation. More profoundly, this paper suggests that there is clear potential and utility in applying approaches used elsewhere to assess economic water security in southern Africa.

Runoff generated in the monsoon months in the upstream parts of the Ganges River basin (GRB) contributes substantially to downstream floods, while water shortages in the dry months affect agricultural production in the basin. This paper examines the potential for subsurface storage (SSS) in the Ganges basin to mitigate floods in the downstream areas and increase the availability of water during drier months. The Soil and Water Assessment Tool (SWAT) is used to estimate “sub-basin” water availability. The water availability estimated is then compared with the sub-basinwise unmet water demand for agriculture. Hydrological analysis reveals that some of the unmet water demand in the subbasin can be met provided it is possible to capture the runoff in sub-surface storage during the monsoon season (June to September). Some of the groundwater recharge is returned to the stream as baseflow and has the potential to increase dry season river flows. To examine the impacts of groundwater recharge on flood inundation and flows in the dry season (October to May), two groundwater recharge scenarios are tested in the Ramganga sub-basin. Increasing groundwater recharge by 35 and 65 % of the current level would increase the baseflow during the dry season by 1.46 billion m3 (34.5 % of the baseline) and 3.01 billion m3 (71.3 % of the baseline), respectively. Analysis of pumping scenarios indicates that 80 000 to 112 000 ha of additional wheat area can be irrigated in the Ramganga sub-basin by additional SSS without reducing the current baseflow volumes. Augmenting SSS reduces the peak flow and flood inundated areas in Ramganga (by up to 13.0 % for the 65 % scenario compared to the baseline), indicating the effectiveness of SSS in reducing areas inundated under floods in the sub-basin. However, this may not be sufficient to effectively control the flood in the downstream areas of the GRB, such as in the state of Bihar (prone to floods), which receives a total flow of 277 billion m3 from upstream sub-basins.

Using biophysical and social analysis methods, this paper evaluated agricultural practices under changing climate in the Koshi Basin and assessed adaptation options. Agricultural trend analysis showed that in the recent three to four decades, the total cultivated area had declined in all parts of the basin except in the Nepal Mountain Region. Household survey results also confirmed such decline and further revealed shifts towards non-agricultural activities. Climate trend analysis showed changes in the frequency of wet and dry days in study districts, implying an increasing chance of flood and drought events. Household surveys further revealed that, in general, people perceived a decline in agricultural water availability and an increase in drought and flood events. The direct impacts of these changes were reduced crop yield, increased fallow lands, displacement of people from settlement areas, sedimentation of cultivable land and damage to properties. Household surveys showed that despite the perceived impacts on agriculture and livelihoods, only limited adaptation options are currently practised. Adaptation efforts are constrained by several factors, including: finance; technical knowledge; lack of awareness about adaptation options; lack of collective action; unclear property rights; and ineffective role of state agencies.

Development partners and public investors assume that spate irrigation reduces household poverty and malnutrition. This article examines whether the poverty profiles of smallholder farmers and the nutritional outcomes of their children have improved as a result of using spate irrigation. The study areas were in two regional states in Ethiopia. Twenty-five users each, both from traditional and modern spate irrigation schemes, and an equal number of non-users responded to a structured questionnaire. Anthropometric measures of 122 children under five were measured using a hanging scale and stadiometer. The results indicated that all poverty indices were significantly lower for the spate irrigation users compared to non-users, and were even lower for modern spate compared to traditional spate systems. Our results did not show gender differences, using sex of the household head as a crude measure of gender, in poverty profiles. Stochastic dominance tests showed that the poverty comparisons between users, traditional and modern, and non-users are statistically robust. It can be concluded that the use of spate irrigation can significantly reduce poverty, and modernizing spate systems further increases its poverty-reduction impact. However, anthropometric measures indicated that use of spate irrigation did not have significant nutritional effects, suggesting the need for nutrition-sensitive interventions, such as nutrition education and awareness and multisectoral collaboration.

Moderate Resolution Imaging Spectro-radiometer (MODIS) time-series Normalized Differential Vegetation Index (NDVI) products are regularly used for vegetation monitoring missions and climate change analysis. However, satellite observation is affected by the atmospheric condition, cloud state and shadows introducing noise in the data. MODIS state flag helps in understanding pixel quality but overestimates the noise and hence its usability requires further scrutiny. This study has analyzed MODIS MOD09A1 annual data set over Sri Lanka. The study presents a simple and effective noise mapping method which integrates four state flag parameters (i.e. cloud state, cloud shadow, cirrus detected, and internal cloud algorithm flag) to estimate Cloud Possibility Index (CPI). Usability of CPI is analyzed along with NDVI for noise elimination. Then the gaps generated due to noise elimination are reconstructed and performance of the reconstruction model is assessed over simulated data with five different levels of random gaps (10–50%) and four different statistical measures (i.e. Root mean square error, mean absolute error, mean bias error, and mean absolute percentage error). The sample-based analysis over homogeneous and heterogeneous pixels have revealed that CPI-based noise elimination has increased the detection accuracy of number of growing cycle from 45–60% to 85–95% in vegetated regions. The study cautions that usage of time-series NDVI data without proper cloud correction mechanism would result in wrong estimation about spatial distribution and intensity of drought, and in our study 50% of area is wrongly reported to be under drought though there was no major drought in 2014.

Remote sensing of soil moisture has reached a level of good maturity and accuracy for which the retrieved products are ready to use in real-world applications. Due to the importance of soil moisture in the partitioning of the water and energy fluxes between the land surface and the atmosphere, a wide range of applications can benefit from the availability of satellite soil moisture products. Specifically, the Advanced SCATterometer (ASCAT) on board the series of Meteorological Operational (Metop) satellites is providing a near real time (and long-term, 9+ years starting from January 2007) soil moisture product, with a nearly daily (sub-daily after the launch of Metop-B) revisit time and a spatial sampling of 12.5 and 25 km. This study first performs a review of the climatic, meteorological, and hydrological studies that use satellite soil moisture products for a better understanding of the water and energy cycle. Specifically, applications that consider satellite soil moisture product for improving their predictions are analyzed and discussed. Moreover, four real examples are shown in which ASCAT soil moisture observations have been successfully applied toward: 1) numerical weather prediction, 2) rainfall estimation, 3) flood forecasting, and 4) drought monitoring and prediction. Finally, the strengths and limitations of ASCAT soil moisture products and the way forward for fully exploiting these data in real-world applications are discussed.

Agriculture is the mainstay of Ethiopia’s economy, contributing more than 40% to GDP and providing a livelihood to about 80% of the population. Agriculture is dominated by smallholders growing predominantly rainfed cereals, making economic performance dependent on rainfall availability. This study used the stochastic frontier production function to analyse the productivity and technical efficiency of 4 different agricultural production systems in Ethiopia; namely, irrigated seasonal farms on traditional irrigation systems, irrigated seasonal farms on modern communal irrigation systems, rainfed seasonal farms for farmers who have access to irrigation and rainfed seasonal farms for farmers who do not have access to irrigation. Simple random samples of farmers were selected from lists of farmers. The sample of farmers constituted 122 from the traditional irrigated sites, 281 from the modern communal irrigated sites and 350 from the control rainfed sites of farmers without access to irrigation. For those farmers, from both traditional and modern communal irrigation, who also had access to rainfed farms, their rainfed farms were included in the sample of rainfed with access to irrigation. This sample constituted 434 farmers. The marginal productivity of land on modern communal irrigation systems shows that this is the smallholder irrigation option that should be developed by the Government of Ethiopia. However, the marginal productivity of land in the ‘rainfed without access to irrigation’ category is higher than that of the traditional irrigated system. Thus additional developed land should be put under ‘rainfed without access to irrigation’ before it is put under traditional irrigation; otherwise it should be developed into modern communal irrigation. The average technical efficiency for the modern irrigated system was estimated to be about 71%, whereas this was estimated to be 78% for the ‘rainfed without access to irrigation’ system. There are potential gains to be realised in improving efficiency in these two systems.

The Tana River is one of Kenya’s most important rivers. It is the principal water source for Nairobi, the capital city, providing water for hydroelectric power generation and irrigation. Several of the flagship projects laid out in Vision 2030 - the blueprint that guides Kenya’s national development – are located in the basin. This report presents the findings of a study to determine the possible impacts of climate change on the hydrology of the basin. Data from seven Regional Circulation Models (RCMs), simulating two Representative Concentration Pathways (RCPs), were used as input to the Soil and Water Assessment Tool (SWAT) hydrological model. For both RCPs, rainfall is projected to increase across the basin over the remainder of the twenty-first century. Associated increases in water yield, groundwater recharge and baseflow point to an improved water resource situation in the future. However, declining natural flow regulation, increased variability, and considerable increases in the frequency and magnitude of floods pose a risk that threatens to undermine development opportunities. Water resource management will be much more difficult than under historic climatic conditions.

The Barotse Floodplain, a designated Ramsar site, is home to thousands of indigenous people along with an extensive wetland ecosystem and food production system. Increasingly it is also a popular tourist destination with its annual Kuomboka festival which celebrates the relocation of the king and the Lozi people to higher ground before the onset of the ood season. This paper presents an integrated approach which cross validates and combines the oodplain residentsapos; perceptions about recent oods with information on ood inundation levels derived from satellite observations. Local residentsapos; surveys were conducted to assess farmers’ perception on the ooding patterns and the impact on their livelihoods. Further, a series of ood inundation maps from 1989 to 2014 generated from remotely sensed Landsat imagery were used to assess the recent patterns of oods. Results show that the oodplain has a population of 33 thousand living in 10,849 small permeant or temporary buildings with a total cropland area of 4976 ha. The oodplain hydrologyand ooding patterns have changed, con rmed by both surveys and satellite image analysis, due to catchment development and changing climate. The average annual inundated areas have increased from about 316 thousand ha in 1989e1998 to 488 thousand ha in 2005 e2014. As a result the inundated cropland and houses increased from 9% to 6% in 1989 to 73% and 47% in 2014, respectively. The timing of the oods has also changed with both delaying and early onset happening more frequently. These changes cause increasing dif culties in ood forecast and preparation using indigenous knowledge, therefore creating greater damages to crops, livestock, and houses. Current oodplain management system is inadequate and new interventions are needed to help manage the oods at a systematic manner.

Northern Bihar is one of the major flood prone region in India affecting thousands of human lives and livelihoods during the recurrent floods occurring due to the monsoonal rains. While it is impossible to prevent the occurrence of extreme flood events, disaster planning can help in mitigating its detrimental effects. Monitoring flood extent using satellite observations just after the flood disasters is a core component of rapid emergency response process, which enables the emergency rescue teams to prioritize their efforts in critical areas to save lives and protect health, in addition to providing near real-time flooding information to the decision makers and planners. The main objective of this study is to demonstrate the utility of less data intensive, but equally robust hydrodynamic models to develop flood extent maps in conjunction with freely available remote sensing imageries at different scales. MODIS TERRA satellite data was used to map flood extent from 2001 to 2016 for entire Bihar. Two hydraulic models namely FLDPLN and RRI applied for the Bagmathi basin to evaluate our objectives. Both these models are of varying complexity but generate flood extent patterns with minimum amount of input data. The proposed approach is suited for mapping flood extents to provide an input information in near real time (h) when there is no availability to detailed hydraulic models and satellite datasets. Flood inundation extents from FLDPLN and RRI models were validated with Landsat-7 and MODIS TERRA derived flood extents for model performance. The results show acceptable spatial agreement between model predicted and Landsat-7 observed flood extents, denoting the utility of these tools for flood mapping application in data scarce environments.

Flooding is one of the most devastating natural hazards in the world and its forecast is essential in flood risk reduction and disaster response decision. The lack of adequate monitoring networks, especially in developing countries prevents near real-time flood prediction that could help to reduce the loss of lives and economic damages. In the last few years, increasing availability of multi-satellite sensors induced to develop new techniques for retrieving river discharge and especially in supporting discharge nowcasting and forecasting activities. Recently, the potential of radar altimetry to estimate water levels and discharge in ungauged river sites with good accuracy has been demonstrated. However, the considerable benefit derived from this technique is attenuated by the low revisit time of the satellite (10 or 35 days, depending on the satellite mission) causing delays on the predicting operations. For this reason, sensors with a higher temporal resolution such as the MODerate resolution Imaging Spectroradiometer (MODIS), working in visible/Infra-Red bands, can support flood forecasting. In this study, we performed the forecast of river discharge by using MODIS and we compared it with the radar altimetry and in-situ data along the Niger-Benue River in Nigeria to develop an operational flood forecasting scheme that could help in rapid emergency response and decision making processes. In the first step, four MODIS products (daily and, 8-day from the TERRA and AQUA satellites) at two gauged sites were used for discharge estimation. Secondly, the capability of remote sensing sensors to forecast discharge a few days (~4 days) in advance at a downstream section using MODIS is analyzed and also compared with the one obtained by the use of radar altimetry by ENVISAT and Jason-2. The results confirmed the capability of the MODIS data to estimate river discharge with performance indices N0.97 and 0.95 in terms of coefficient of correlation and Nash Sutcliffe efficiency. In particular, RMSE does not exceed 1300 m3 /s and the fractional RMSE ranges between 0.15 and 0.23. For the forecasting exercise, both altimetry and MODIS provide satisfactory results with positive coefficient of persistence considering 4 days of lead time (N0.34). Although altimetry was found to be more accurate in the forecasting of river discharge (RMSE ~350 m3 /s), the much higher temporal resolution of MODIS guarantees a continuity that is more suitable to address operational activities.

Wetlands can only be well managed if their spatial location and extent are accurately documented, which presents a problem as wetland type and morphology are highly variable. Current efforts to delineate wetland extent are varied, resulting in a host of inconsistent and incomparable inventories. This study, done in the Witbank Dam Catchment in Mpumalanga Province of South Africa, explores a remote-sensing technique to delineate wetland extent and assesses the seasonal variations of the inundated area. The objective was to monitor the spatio-temporal changes of wetlands over time through remote sensing and GIS for effective wetland management. Multispectral satellite images, together with a digital elevation model (DEM), were used to delineate wetland extent. The seasonal variations of the inundated area were assessed through an analysis of monthly water indices derived from the normalised difference water index (NDWI). Landsat images and DEM were used to delineate wetland extent and MODIS images were used to assess seasonal variation of the inundated area. A time-series trend analysis on the delineated wetlands shows a declining tendency from 2000 to 2015, which could worsen in the coming few years if no remedial action is taken. Wetland area declined by 19% in the study area over the period under review. An analysis of NDWI indices on the wetland area showed that wetland inundated area is highly variable, exhibiting an increasing variability over time. An overlay of wetland area on cultivated land showed that 21% of the wetland area is subjected to cultivation which is a major contributing factor to wetland degradation.

Challenges of governance often constitute critical obstacles to efforts to equitably improve livelihoods in social-ecological systems. Yet, just as often, these challenges go unspoken, or are viewed as fixed parts of the context, beyond the scope of influence of agricultural, development, or natural resource management initiatives. What does it take to get governance obstacles and opportunities out in the open, creating the space for constructive dialogue and collective action that can help to address them? We respond to this question by comparing experiences of participatory action research (PAR) in coastal and floodplain systems in four countries (Zambia, Solomon Islands, Bangladesh, and Cambodia) with a focus on understanding how to build more equitable governance arrangements. We found that governance improvement was often an implicit or secondary objective of initiatives that initially sought to address more technical natural resource or livelihood-related development challenges. We argue that using PAR principles of ownership, equity, shared analysis, and feedback built trust and helped to identify and act upon opportunities to address more difficult-to-shift dimensions of governance particularly in terms of stakeholder representation, distribution of authority, and accountability. Our findings suggest that the engaged and embedded approach of researcher-facilitators can help move from identifying opportunities for governance change to supporting stakeholders as they build more equitable governance arrangements.

The doubling of global food demand by 2050 is driving resurgence in interventions for agricultural intensification. Globally, 700 million people are dependent on floodplain or coastal systems. Increased productivity in these aquatic agricultural systems is important for meeting current and future food demand. Agricultural intensification in aquatic agricultural systems has contributed to increased agricultural production, yet these increases have not necessarily resulted in broader development outcomes for those most in need. Here we review studies of interventions that have sought to improve productivity in aquatic agricultural systems in Bangladesh, Cambodia and Zambia. We review evidence of development outcomes from these interventions and the particular role of participatory approaches in intervention design and deployment. There was evidence of increases in productivity in 20 of the 31 studies reviewed. Yet, productivity was only measured beyond the life of the intervention in one case, income and food security improvements were rarely quantified, and the social distribution of benefits rarely described. Participatory approaches were employed in 15 studies, and there was some evidence that development outcomes were more substantial than in cases that were less participatory. To explore the impact of participatory approaches further, we examined five empirical cases. Review and empirical cases provide preliminary evidence suggesting participatory approaches contribute to ensuring agriculture and aquaculture interventions into aquatic agricultural systems may better fit local contexts, are sustained longer, and are more able to deliver development benefits to those most in need. A worthy focus of future research would be comparison between outcomes achieved from interventions with differing levels of participation, and the social differentiation of outcomes.

This study investigated the dependence of three riparian communities on ecosystem services in northern Ghana. Participatory mapping and ranking exercises in gender-segregated groups were used to elicit information on the communities’ livelihoods. The most important ecosystem-based activities (EBA) are farming, fishing, livestock watering and grazing, collection of wild fruits and vegetables, and provision of water for domestic use. The major EBA are dependent on the seasonal flows of the White Volta River, which are under pressure due to climatic and other anthropogenic changes. For example, observed delays in the start of the rainy season are affecting rainfed agricultural activities on the floodplains. Delayed planting on the floodplains results in damage to, or loss of, crops as floods arrive before the harvest. Moreover, the Bagr Dam in Burkina Faso, built upstream of the communities, has impacted the natural river flow. The planned Pwalugu Dam may, depending on the final operations, support or affect EBA. We, therefore, recommend that operations of the Pwalugu Dam should take into consideration the flow requirements of EBA downstream of the dam.

Although the Ganges River Basin (GRB) has abundant water resources, the seasonal monsoon causes a mismatch in water supply and demand, which creates severe water-related challenges for the people living in the basin, the rapidly growing economy and the environment. Addressing these increasing challenges will depend on how people manage the basin’s groundwater resources, on which the reliance will increase further due to limited prospects for additional surface storage development. This report assesses the potential of the Ganges Water Machine (GWM), a concept proposed 40 years ago, to meet the increasing water demand through groundwater, and mitigate the impacts of floods and droughts. The GWM provides additional subsurface storage (SSS) through the accelerated use of groundwater prior to the onset of the monsoon season, and subsequent recharging of this SSS through monsoon surface runoff. It was identified that there is potential to enhance SSS through managed aquifer recharge during the monsoon season, and to use solar energy for groundwater pumping, which is financially more viable than using diesel as practiced in many areas at present. The report further explores the limitations associated with water quality issues for pumping and recharge in the GRB, and discusses other related challenges, including availability of land for recharge structures and people’s willingness to increase the cropping intensity beyond the present level.

The paper presents a moderate resolution imaging spectroradiometer (MODIS) time-series imagery-based algorithm for detection and mapping of seasonal and annual changes in flood extent, and tests this using the flooding of the Indus River Basin in 2010 – one of the greatest recent disasters that affected more than 25 million people in Pakistan. The algorithm was applied to produce inundation maps for 10 annual flood seasons over the period from 2000 to 2011. The MODIS flood products were validated in comparison with advanced land observing system (ALOS) sensors, which have both advanced visible and near infrared radiometer and phased array type L-band synthetic images using the flood fraction comparison method. A simple threshold method is created to cluster the data to identify the flood pixels in the imagery. Calculations are then made to estimate a flood area for each resolution. A statistical study is performed to analyze false positive and false negative rates using the ALOS sensors as ‘ground truth’. Comparison of two flood products at a grid size of 10 km resulted in the coefficient of determination range of 0.72–0.97. This research points to a relevant spatial resolution that could be effectively used to obtain accurate mapped products of the extent of the inundated area. The approach can be used to quantify the damage caused by floods.

The Indian Ocean Tsunami of December 26, 2004 devastated coastal ecosystems across South Asia. Along the coastal regions of South India, increased groundwater levels (GWL), largely caused by saltwater intrusion, infiltration from inundated land, and disturbance of freshwater lenses, were reported. Many agencies allocated funding for restoration and rehabilitation projects. However, to streamline funding allocation efforts, district-level groundwater inundation/recession data would have been a useful tool for planners. Thus, to ensure better preparedness for future disaster relief operations, it is crucial to quantify pre- and post-tsunami groundwater levels across coastal districts in India. Since regional scale GWL field observations are not often available, this study instead used space gravimetry data from NASA’s Gravity Recovery and Climate Experiment (GRACE), along with soil moisture data from the Global Land Data Assimilation Systems (GLDAS), to quantify GWL fluctuations caused by the tsunami. A time-series analysis of equivalent groundwater thickness was developed for February 2004–December 2005 and the results indicated a net increase of 274 % in GWLs along coastal regions in Tamil Nadu following the tsunami. The net recharge volume of groundwater due to the tsunami was 16.8 km3, just 15 % lower than the total annual groundwater recharge (19.8 km3) for the state of Tamil Nadu. Additionally, GWLs returned to average within 3 months following the tsunami. The analysis demonstrated the utility of remotely sensed data in predicting and assessing the impacts of natural disasters.

Availability of reliable, timely and accurate rainfall data is constraining the establishment of flood forecasting and early warning systems in many parts of Africa. We evaluated the potential of satellite and weather forecast data as input to a parsimonious flood forecasting model to provide information for flood early warning in the central part of Nigeria. We calibrated the HEC-HMS rainfall-runoff model using rainfall data from post real time Tropical Rainfall Measuring Mission (TRMM) Multi satellite Precipitation Analysis product (TMPA). Real time TMPA satellite rainfall estimates and European Centre for MediumRange Weather Forecasts (ECMWF) rainfall products were tested for flood forecasting. The implication of removing the systematic errors of the satellite rainfall estimates (SREs) was explored. Performance of the rainfall-runoff model was assessed using visual inspection of simulated and observed hydrographs and a set of performance indicators. The forecast skill was assessed for 1–6 days lead time using categorical verification statistics such as Probability Of Detection (POD), Frequency Of Hit (FOH) and Frequency Of Miss (FOM). The model performance satisfactorily reproduced the pattern and volume of the observed stream flow hydrograph of Benue River. Overall, our results show that SREs and rainfall forecasts from weather models have great potential to serve as model inputs for real-time flood forecasting in data scarce areas. For these data to receive application in African transboundary basins, we suggest (i) removing their systematic error to further improve flood forecast skill; (ii) improving rainfall forecasts; and (iii) improving data sharing between riparian countries.

Reliance on rainfall for agriculture and increased climate change and variability pose growing production risks in developing countries. Agriculture in Sub-Saharan Africa is dominated by smallholder farmers who depend mainly on rain-fed agriculture, putting food security at both household and national levels at risk, especially in the event of drought. Investment in smallholder irrigation becomes a priority in developing countries if food security and national development goals are to be met, as their economies are agro-based. This study evaluates the impact of investment in smallholder irrigation schemes in Malawi on improving crop production and productivity in comparison with rain-fed agriculture. The area under smallholder irrigation schemes increased from 15 988 ha in 2003 to about 42 986 ha in 2011, contributing immensely to national food production. Irrigated maize production increased from 78 159 tons in 2000 to 544 378 tons in 2013.

The Ganges River basin faces severe water challenges related to a mismatch between supply and demand. Although the basin has abundant surface water and groundwater resources, the seasonal monsoon causes a mismatch between supply and demand as well as flooding. Water availability and flood potential is high during the 3–4 months (June–September) of the monsoon season. Yet, the highest demands occur during the 8–9 months (October–May) of the non-monsoon period. Addressing this mismatch, which is likely to increase with increasing demand, requires substantial additional storage for both flood reduction and improvements in water supply. Due to hydrogeological, environmental, and social constraints, expansion of surface storage in the Ganges River basin is problematic. A range of interventions that focus more on the use of subsurface storage (SSS), and on the acceleration of surface–subsurface water exchange, has long been known as the Ganges Water Machine (GWM). The approach of the GWM for providing such SSS is through additional pumping and depleting of the groundwater resources prior to the onset of the monsoon season and recharging the SSS through monsoon surface runoff. An important condition for creating such SSS is the degree of unmet water demand. The paper shows that the potential unmet water demand ranging from 59 to 124 Bm3 year-1 exists under two different irrigation water use scenarios: (i) to increase irrigation in the Rabi (November–March) and hot weather (April–May) seasons in India, and the Aman (July–November) and Boro (December–May) seasons in Bangladesh, to the entire irrigable area, and (ii) to provide irrigation to Rabi and the hot weather season in India and the Aman and Boro seasons in Bangladesh to the entire cropped area. However, the potential for realizing the unmet irrigation demand is high only in 7 sub-basins in the northern and eastern parts, is moderate to low in 11 sub-basins in the middle, and has little or no potential in 4 sub-basins in the western part of the Ganges basin. Overall, a revived GWM plan has the potential to meet 45–84 Bm3year-1 of unmet water demand.

Deficit irrigation could be considered as one potential option to improve water productivity and obtain some level of assured income under water scarcity and drought conditions in Central Asia. This article investigates water productivity and economic returns to two varieties of potato crop under four different soilmoisture regimes in Uzbekistan. Results suggest that deficit irrigation may not be considered as an option to improve water productivity of potato crop, particularly when the deficit is high. However, deficit irrigation options could be still considered as a viable option to maintain food security and some assured farm income even under extreme drought conditions.

Deficit irrigation could be considered as one potential option to improve water productivity and obtain some level of assured income under water scarcity and drought conditions in Central Asia. This article investigates water productivity and economic returns to two varieties of potato crop under four different soilmoisture regimes in Uzbekistan. Results suggest that deficit irrigation may not be considered as an option to improve water productivity of potato crop, particularly when the deficit is high. However, deficit irrigation options could be still considered as a viable option to maintain food security and some assured farm income even under extreme drought conditions.

Braided reaches of large rivers in alluvial plains show major morphological changes, particularly the external bank erosion, due to the flood events. This paper highlights the bank erosion and channel evolution induced by eleven different flood events in a 7-km long reach of the River Chenab, Pakistan. The impact of floods on river bank erosion and channel evolution is analyzed under low and high flow conditions. Flood-induced changes, for river’s external banks and channel evolution, were assessed by processing Landsat ETM+ images in ArcGIS tool, and their inter-relationship is evaluated through regression analysis. The results revealed that the major morphological changes were triggered by the flood events occurred during the high flow or Monsoon season (July–September), whereas the flood events of similar magnitude occurring during low flow season (October–March) did not induce such changes. Mostly, the erosion remained limited to the middle part of the reach,where the branch channel flows along the bank. The average annual bank erosion rates are much higher as compared with a global scale. Data analysis showed a strong correlation between the mean high flows and total bank erosion indicating that Monsoon seasonal flows and floods are responsible for bank erosion. The present study further identifies the river bank locations highly susceptible to erosion by developing the correlation between bank erosion and branch channel progression. Strong correlation for bank erosion could be established with the shift of branch channels position flowing along the banks in braided reaches of sand bed rivers. However, the presence of sand bars along the river banks resulted in reduced erosion that weakens this relationship. The findings of the present study can help develop better understanding about the bank erosion process and constitute a key element to inform and improve river bank management.

By altering evapotranspiration and influencing how water is routed and stored in a basin, natural and agrarian ecosystems affect river flow. To quantify the impact of ecosystems on streamflow in two large river basins in Asia and Africa, simple statistical relationships were calculated, enabling flow characteristics to be ascertained from basic catchment features. This approach allows the impact of specified land-use change on streamflow to be determined. For example, it shows that extending paddy areas in the Mekong River Basin reduces downstream low flows, while conversion of forests to crops increases the magnitude of downstream floods in the Volta River Basin. The approach could assist river basin planners to better account for flow-related ecosystem services.

While transboundary waters are widely advocated to be best managed at the basin level, practical experience in transboundary waters at the basin vis--vis other scales has not been systematically examined. To understand past experiences in transboundary water management at alternate scales, this paper: (i) determines the relative abundance of water treaties at different scales and (ii) elucidates how transboundary water law varies according to the scale to which it applies. The paper developed a scale typology with six groups, and systematically applied it to stratify transboundary water treaties. Treaty contents were then compared across scales according to the following set of parameters: primary issue area, temporal development, and important water management attributes. Results of this work reveal: (i) treaties tend to focus on hydropower and flood control at smaller scales, and organizations and policies at larger scales; (ii) a temporal trend toward treaties concluded at larger scales; and (iii) a higher proportion of treaties is at larger scales in Africa and Asia than in Europe and the Americas. These findings suggest that smaller scale cooperation may constitute a more constructive scale in which to achieve development-oriented cooperation. Further, scope may exist to complement basin scale cooperation with cooperation at smaller scales, in order to optimize transboundary water management. In the context of basin-wide management frameworks, Africa and Asia may benefit from greater emphasis on small-scale transboundary water cooperation.

The impact of shallow subsurface drainage was investigated as a pilot study on a 0.13 ha plot of a farmer’s field located in Batiaghata, Khulna District, Bangladesh, in the floodplain of the Bay of Bengal. The drainage design differed from traditional subsurface tile drains in two respects: (i) the depth of drains was shallow (30 cm); and (ii) the design did not include a sump and accessories such as pumps (drainage outlets were tidal). A monsoonal paddy rice crop followed by a winter sunflower crop was evaluated. The experimental treatment was a shallow subsurface drainage system with a drain depth of 0.3 m and drain spacing of 8 m. Measurements of surface flooding depth and groundwater table depth were made weekly and subsurface drainage discharge during managed drainage of the field was measured to determine system responsiveness. The managed subsurface drainage enabled the establishment of the winter sunflower crop 1.5 months earlier than the usual local practice, increased the yield and facilitated safe harvest, avoiding pre-monsoonal rainfall damage. Farmers expressed increased interest in managed subsurface drainage for its potential for early establishment of rabi crops and increased yields in the study area. This study outlines the potential benefits resulting from subsurface drainage in Khulna District.

Beginning on 14 May 2016, a low pressure area over the Bay of Bengal caused torrential rain to fall across Sri Lanka. Some locations saw over 350 mm (13.77 inches) of rain fall in 24 hours. Floods and landslides have caused havoc in as many as 19 districts of the country, including around Colombo, causing floods and landslides which affected half a million people with causality reported over 100 and estimated economic losses closer to $2billion. In recent years, due to an increasing number in the frequency and intensity of extreme meteorological events potentially related to climate change, a growing attention has been paid to the operational use of satellite remote sensing applied to emergency response and relief measures. This is mainly due to the large and timely availability of different types of remotely sensed data as well as geospatial information acquired in the field which may be potentially exploited in the different phases of the disaster management cycle. IWMI jointly with Disaster Management Centre (DMC), Sri Lanka activated disaster charter with Sentinel Asia and escalated International Disaster Charter to access satellite images during the crisis response phase to support government agencies in relief and rescue measures. A total of 13 satellite images both microwave and optical datasets (ALOS-2, Sentinel-1, RISAT-1, RADARSAT-2, TerraSAR-X, FORMOSAT, Landsat-8) were provided by various space agencies to generate flood situation maps on a daily basis. The emergency flood situation maps were regularly shared to national and international organizations within 3-4 hours after the post-event image is acquired by the space agencies to support in relief measures. The derived flood maps were overlaid with local administrative division to give specific information on the priority area to the DMC and Air Force authorities to focus relief measures. These rapid response maps can further be used for postdisaster relief policy and damage assessment.

Increasing frequency of drought events coupled uncertainty imparted by climate change pose grave threat to agriculture and thereby overall food security. This is especially true in South Asian region where world’s largest concentration of people depends on agriculture for their livelihood. Indices derived from remote sensing datasets signifying different bio-physical aspects are increasingly used for operational drought monitoring. This study focuses on evaluating a newly created index for agricultural drought referred as Integrated Drought Severity Index (IDSI) in comparison with the traditional Standardized Precipitation Index (SPI) primarily representing precipitation condition to delineate drought using custom created ArcGIS toolbox for a period of fourteen years (2001-2014) in Sri Lanka. SPI created using remotely sensed PERSIANN precipitation dataset was compared with the IDSI created using hybrid datasets. IDSI is created based on seamless mosaic of remotely sensed multi-sensor data that takes vegetation (computed from MODIS data product MOD09A1), temperature (MOD11A2) and precipitation (TRMM amp; GPM) status into consideration. The comparative study was made to assess the efficiency of newly created index and ArcGIS toolbox techniques for near real-time monitoring of spatio-temporal extent of agricultural drought. The result showed significant correlation of 0.85 between the two indices signifying the potential of using IDSI that integrates the response of agriculture drought variables (vegetation, rainfall, temperature and soil moisture) in monitoring shortterm drought and application in risk reduction measures.

Responding to rainfall variability has always been one of the most critical risks facing farmers. It is also an integral part of the job of water managers, whether it be designing interventions for flood management, improving the reliability of water supply for irrigation or advising on priorities during drought conditions. The conventional tools and approaches employed are no longer sufficient to manage the increasing uncertainty and incidence of extreme climate events, and the consequent effects these have on human vulnerability and food security. To be effective, the technological advances need to be matched with physical, institutional and management innovations that transcend sectors, and place adaptation and responsiveness to variability at the centre of the approach. This chapter examines a number of these challenges and possible solutions at a range of scales, from ‘climate-smart villages’ to national policy, with a focus on Asia and India, in particular.

In developing countries millions of people live a life of subsistence agriculture, mired in poverty, with limited access to basic human needs, such as food and water. Under such circumstances wetlands, through the provision of a range of direct and indirect ecosystem services, play a vital role in supporting and sustaining peoples’ livelihoods and hence, their health. This chapter discusses the role of wetlands in the context of the sustainable livelihoods framework in which wetlands are viewed as an asset for the rural poor in the form of “natural capital”. The framework is used to illustrate how ecosystem services, livelihoods and health are entwined and how the ecosystem services provided by wetlands can be converted to human health either directly or via other livelihood assets. It highlights the contributions that wetlands make to basic human needs and, either directly or through transformations to other forms of livelihood capital, the support they provide to livelihoods and overall well-being.

At Marala barrage, two canals, i.e. Marala Ravi Link Canal (MRLC) and Upper Chenab Canal (UCC) off-take from left side of the River Chenab. MRLC has a very old history of experiencing sedimentation issues. Several attempts have been made to counterfoil or minimize this problem in the recent past. Two remarkable measures are the remodeling of MRLC in 2000-2001 (in-tervention-1) and the shifting of the confluence point of a heavily sediment-laden upstream tributary of the Chenab River by construction of a spur dike in 2004 (intervention-2). This paper investigates the effectiveness of these structural interventions as sedimentation control measures. The baseline period is selected from 1997 to 2000 and the impact is analyzed for two post-intervention time steps, i.e. evaluation period-1 ranging from 2001 to 2004 and evaluation period-2 from 2005 to 2011. Results obtained from double mass analysis revealed that sediment load increased by 33 and 8 % due to intervention-1, while decreased by 12 and 22 % due to intervention-2 in MRLC and UCC, respectively. The results suggest that monsoon floods are mainly responsible for sediment loading in the canals (66 % for UCC and 73 % for MRLC), supported by the finding that effective discharge (1900 m3 s-1) is almost twice the mean annual river discharge. The discharge classes between 900 and 2900 m3 s- 1 are mainly responsible for major proportion (89 % in MRLC and 86 % in UCC) of the total sediment load over the 15-year study period. The intervention-1 could not minimize the sediment entry into the canals; rather it aggravated the situation. The intervention-2, however, proved a useful structural measure in this regard.

The growing urban demand for food and changing diets are two of the main factors for changing urban food systems in terms of food quantity and diversity, as well as underlying production and distribution systems. In order to meet the urban food needs while minimising negative environmental effects, short supply chains have been advocated in recent years. In spite of the growing attention to “local” or “urban“ food in research and development, there are only very few empirical studies which systematically analyse the actual contribution of urban and periurban production to urban food supply in a standardised way. This study as part of two PhD projects aims to quantify and map food flows supplying urban populations in the cities of Tamale, Ghana and Ouagadougou, Burkina Faso, both cities that are characterised by high urban growth rates and high incidences of food insecurity. Food flows were recorded at roads entering the cities and at major markets during the peak and lean season. Data collection will extend over two years, and therefore only first preliminary results are available so far (Tamale for the peak season 2013, and lean season 2014; Ouagadougou for the lean season 2014). First results show that in both cities the majority of unprocessed staple crops are produced in rural areas and channelled through village markets to the cities while leafy vegetables are produced during the dry season in irrigated urban and peri-urban agriculture (UPA). In Tamale, imports play a minor role: rice is the only food crop imported at large scale from outside Africa (preliminary results indicate that about half of the rice consumed in both cities is imported), whereas sub-regional trade plays a role with respect to onion (from Niger) and tomato supply (from Burkina Faso during the lean season). Ouagadougou’s status as national capital is reflected in the larger diversity of food items in the markets and the relatively longer distances (partly imported) food travels. The two case studies suggest that diversifying food sources can be a means to minimise risks and to ensure access to favourable market prices which contributes to a more resilient urban food supply system. This might change with increasing economic status and growing city size, when creating space for UPA and supporting rural small holders will become more important to maintain the mix.

Flood forecasting in the downstream part of any hydrological basin is extremely difficult due to the lack of basin-wide hydrological information in near real-time and the absence of a data-sharing treaty among the transboundary nations. The accuracy of forecasts emerging from a hydrological model could be compromised without prior knowledge of the day-to-day flow regulation at different locations upstream of the Niger and Benue rivers. Only satellite altimeter monitoring allows us to identify the actual river levels upstream that reflect the human intervention at that location. This is critical for making accurate downstream forecasts. This present study aims to demonstrate the capability of altimeter-based flood forecasting along the Niger-Benue River in Nigeria. The study includes the comparison of decadal (at every 10 days from Jason-2) or monthly (at every 35 days from Envisat/AltiKa) observations from 2002 to 2014, with historical in situ measurements from 1990 to 2012. The water level obtained from these sources shows a good correlation (0.7–0.9). After validation of hydrological parameters obtained from two sources, a quantitative relation (rating curve) of upstream water level and downstream discharge is derived. This relation is then adopted for calculation of discharge at observation points, which is used to propagate the flow downstream at a desired location using a hydraulic river model. Results from this study from Jason-2 shows a promising correlation (R2 90% with a Nash-Sutcliffe coefficient of more than 0.70) with 5 days ahead of downstream flow prediction over the Benue stream.

Flood management is adopting a more risk-based approach, whereby flood risk is the product of the probability and consequences of flooding. Two-dimensional flood inundation modeling is a widely used tool to aid flood-risk management. The aim of this study is to develop a flood inundation model that uses historical flow data to produce flood-risk maps, which will help to identify flood protection measures in the rural areas of Sri Lanka. The LISFLOOD-FP model was developed at the basin scale using available historical data, and also through coupling with a hydrological modelling system, to map the inundation extent and depth. Results from the flood inundation model were evaluated using Synthetic Aperture Radar (SAR) images to assess product accuracy. The impacts of flooding on agriculture and livelihoods were analyzed to assess the flood risks. It was identified that most of the areas under paddy cultivation that were located near the middle and downstream part of the river basin are more susceptible to flood risks. This paper also proposes potential countermeasures for future natural disasters to prevent and mitigate possible damages.

The ‘WISE-UP to climate’ project aims to demonstrate the value of natural infrastructure as a ‘nature-based solution’ for climate change adaptation and sustainable development. Within the Tana River Basin, both natural and built infrastructure provide livelihood benefits for people. Understanding the interrelationships between the two types of infrastructure is a prerequisite for sustainable water resources development and management. This is particularly true as pressures on water resources intensify and the impacts of climate change increase. This report provides an overview of the biophysical characteristics, ecosystem services and links to livelihoods within the basin.

Surface runoff generated in the monsoon months in the upstream parts of the Ganges River Basin contributes substantially to downstream floods, while water shortages in the dry months affect agricultural production in the basin. This paper examines the parts (sub-basins) of the Ganges that have the potential for augmenting subsurface storage (SSS), increase the availability of water for agriculture and other uses, and mitigate the floods in the downstream areas. The Soil and Water Assessment Tool (SWAT) is used to estimate sub-basin-wise water availability. The water availability estimated is then compared with the sub-basin-wise un-met water demand for agriculture. Hy-drological analyses revealed that five sub-basins produced more than 10 billion cubic meters (B m3) of annual surface runoff consistently during the simulation period. In these sub-basins, less than 50 % of the annual surface runoff is sufficient to irrigate all irrigable land in both the Rabi (November to March) and summer (April to May) seasons. Further, for most of the sub-basins, there is sufficient water to meet the un-met water demand, provided that it is possible to capture the surface runoff during the wet season. It is estimated that the average flow to Bihar State from the upstream of the Ganges, a downstream basin location, is 277 121 B m3, which is more than double the rainfall in the state alone. Strong relationships between outflows from the upstream sub-basins and the inflows to Bihar State suggested that flood inundation in the state could be reduced by capturing a portion of the upstream flows during the peak runoff periods.

The Ganges River Basin may have a major pending water crisis. Although the basin has abundant surface water and groundwater resources, the seasonal monsoon causes a mismatch between supply and demand as well as flooding. Water availability and flood potential is high during the 3–4 months of the monsoon season. Yet, the highest demands occur during the 8–9 months of the non-monsoon period. Addressing this mismatch requires substantial additional storage for both flood reduction and improvements in water supply. Due to hydrogeological, environmental, and social constraints, expansion of surface storage in the Ganges River Basin is problematic. A range of in- terventions that focus more on the use of subsurface storage (SSS), and on the acceleration of surface–subsurface water exchange, have long been known as the “Ganges Water Machine”. One approach for providing such SSS is through additional pumping prior to the onset of the monsoon season. An important necessary condition for creating such SSS is the degree of unmet water demand. This paper highlights that an unmet water demand ranging from 59 to 119 Bm3 exists under two different irrigation water use scenarios: (i) to increase Rabi and hot weather season irrigation to the entire irrigable area, and (ii) to provide Rabi and hot weather season irrigation to the entire cropped area. This paper shows that SSS can enhance water supply, and provide benefits for irrigation and other water use sectors. In addition, it can buffer the inherent variability in water supply and mitigate extreme flooding, especially in the downstream parts of the basin. It can also increase river flow during low-flow months via baseflow or enable the re-allocation of irrigation canal water. Importantly, SSS can mitigate the negative effects of both flooding and water scarcity in the same year, which often affects the most vulnerable segments of society – women and children, the poor and other disadvantaged social groups.

Despite widespread recognition of the importance of irrigation development in southern Africa, no comprehensive examination exists on the performance of past irrigation schemes in the region. This paper systematically examines existing literature on irrigation schemes in southern Africa in order to: (i) determine the proportion that can be considered successful; and (ii) identify and rank factors that explain variation in performance. The results indicate that some 59% of irrigation schemes in southern Africa can be considered successful. Factors associated with successful performance include: management style, irrigation method, crop mix, type of financier and geography. The levels of success identified through this review validate calls to increase the irrigated area in southern Africa. These results nonetheless highlight opportunities to strengthen the way in which future irrigation schemes are undertaken. In particular, these results may call for increased use of sprinkler irrigation and reduced use of flood irrigation with pumping. The results also suggest more investment could be channelled into schemes focused on maize–vegetable crop rotations and sugar cane, and caution applied to government management of schemes.

The concept of ‘Underground Taming of Floods for Irrigation’ (UTFI) is introduced as an approach for co-managing floods and droughts at the river basin scale. UTFI involves strategic recharge of aquifers upstream during periods of high flow, thereby preventing local and downstream flooding, and simultaneously providing additional groundwater for irrigation during the dry season for livelihood improvement. Three key stages in moving UTFI from the concept stage to mainstream implementation are discussed. An analysis of prospects in the Ganges River Basin are revealed from the earliest stage of mapping of suitability at the watershed level through to the latest stages of identifying and setting up the first pilot trial in the Upper Ganges, where a comprehensive evaluation is under way. If UTFI can be verified then there is enormous potential to apply it to address climate change adaptation/mitigation and disaster risk reduction challenges globally.

Large-scale estimates of the area of terrestrial surface waters have greatly improved over time, in particular through the development of multi-satellite methodologies, but the generally coarse spatial resolution (tens of kms) of global observations is still inadequate for many ecological applications. The goal of this study is to introduce a new, globally applicable downscaling method and to demonstrate its applicability to derive fine resolution results from coarse global inundation estimates. The downscaling procedure predicts the location of surface water cover with an inundation probability map that was generated by bagged decision trees using globally available topographic and hydrographic information from the SRTM-derived HydroSHEDS database and trained on the wetland extent of the GLC2000 global land cover map. We applied the downscaling technique to the Global Inundation Extent from Multi-Satellites (GIEMS) dataset to produce a new high-resolution inundation map at a pixel size of 15 arc-seconds, termed GIEMS-D15. GIEMS-D15 represents three states of land surface inundation extents: mean annual minimum (total area, 6.5 × 106 km2 ), mean annual maximum (12.1 × 106 km2 ), and long-term maximum ( 17.3 × 106 km2 ); the latter depicts the largest surface water area of any global map to date. While the accuracy of GIEMS-D15 reflects distribution errors introduced by the downscaling process as well as errors from the original satellite estimates, overall accuracy is good yet spatially variable. A comparison against regional wetland cover maps generated by independent observations shows that the results adequately represent large floodplains and wetlands. GIEMS-D15 offers a higher resolution delineation of inundated areas than previously available for the assessment of global freshwater resources and the study of large floodplain and wetland ecosystems. The technique of applying inundation probabilities also allows for coupling with coarse-scale hydro-climatological model simulations.

Over last decades, we have witnessed an upward global trend in natural disaster occurrence. Hydrological and meteorological disasters are the main contributors to this pattern. In 2011, hydrological disaster, such as floods and wet mass movements, represented 52% of the overall disaster reported, causing 139.8 million victims and more than U.S. $70 billion in damages. Remote sensing from space plays an important role in flood mapping and flood risk assessment. Satellite images acquired in both optical and microwave range of electro-magnetic emissions are utilized for solving many problems related to flood risk management. This paper presents two different research activities (1) flood detection algorithm which uses vegetation and water indices (NDVI, EVI, LSWI, DVEL) at a spatial resolution of 500m and time period 2000 – 2013 using MODIS Terra/Aqua and JAXA PALSAR satellite to spatially and temporally quantify flood inundation extent at a continental scale in South Asia, Southeast Asia and Nigeria in the context of emergency response and (2) blending satellite data and RADAR (Rapid Agriculture Disaster Assessment Routine) tool for rapid flood damage assessment in agriculture with a case study in Sri Lanka. The results of the present study will provide valuable information to flood policy makers and flood disaster researchers.

Flood water harvesting and underground storage is a concept that has received significant attention in many regions of the world. Its intention is to capture floodwater from currently flooded areas and to store it for later use, in order to both, reduce damage caused by floods, as well as to satisfy demands for water during drier periods. This paper presents a preliminary analysis of the prospects for its realization in Sri Lanka. A coarse scale suitability index is constructed and mapped at district level in order to identify the districts having higher prospects for its implementation. Preliminary results indicate three main clusters of highly suitable districts, subject to favourable geological conditions. Cluster 1 consists of Ampara and Batticalao, Cluster 2 of Kurunegala, Anuradhapura and Mannar, and Cluster 3 of Ratnapura. The potential for groundwater recharge of the highly suitable clusters need special investigation prior to arriving at concrete conclusions. If successfully implemented, this concept may prove a valuable intervention for adapting to current and future floods and droughts.

Sri Lanka is facing severe flood events during monsoon rainfall in each year all over the country. The rapid development of remote sensing and widely available satellite images can be used effectively to map the flood inundation in past years. This study is focused on the mapping of flood inundation together with flood recurrent based on both optical (MODIS) and microwave (ALOS/PALSAR) satellite images. In the first stage MODIS images with spatial resolution of 500m and temporal interval of eight day was used to map flood recurrent areas for risk assessment using images from 2000 to 2011. In the second state 16 satellite images from ALOS PALSAR images between 2006 and 2011 was analyzed by using pixel threshold value to map the flooded and non-flooded areas. The flood recurrent products from both MODIS and PALSAR images were generated to represent the repetition of flood inundated areas. The analysis of the results indicated that the PALSAR image based flood inundation mapping is much accurate and useful in the context of spatial variability than the temporal variability. The accurate land-cover map is also important to assess the flood damages and evaluate the future development and the cultivation planning. But there is no such an accurate and detailed land-cove map available for Sri Lanka to assess the flood damages. Thus, this study was focused on the preparation of land-cover map with GIS and RS approach. The land-cover classification was carried out by image fusion of optical (LANDSAT) and microwave (ALOS/PALSAR) under High Pass Filtering (HPF) technique. Unsupervised image classification method was used to classify the fused image in to different land-cover classes. Accuracy assessment of land-cover classification was conducted using existing ground truth information and Google Earth with as resulted in the overall accuracy as 71.16% and the Kappa statistics as 62.83%.

Vietnam’s irrigation development policy directions are divided between the objective to continue increasing rice production through agricultural intensification and to improve farmer’s livelihoods through crop diversification and integrated farming. While the first objective requires the construction of new large-scale irrigation system in deeply flooded area of the Vietnamese Mekong River Delta, the latter demands the modification in management of existing irrigation physical infrastructure for non-rice crops, in particular brackish aquaculture in the coastal zones. This article looks at Vietnam’s irrigation policy formulation processes in the last three and half decades in relation to the idea of polycentric governance. It discusses the current shortcomings and potential role of polycentric governance networks to capture stakeholders’ interests at multiple governance levels essential for future policy development. It partially sheds light on the dark side of water governance, bringing to light the fragmented polycentric decision-making processes in Vietnam’s irrigation development policies.

This paper examines perceived climate risks, their impacts, and existing adaptation practices at the local level, including the role of local institutions. The analysis focuses on two selected areas in Vietnam and Thailand. The paper is based on the information collected through key informant interviews at provincial and district level, focus group discussions at village level, and household survey. Several adaptation practices exist at local level to deal with the perceived risks of drought, floods, and salinity intrusion. Most of the adaptation practices were autonomous focusing on coping with short-term risks rather than structural longterm climate risks. Some adaptation practices, such as crop insurance and regulatory measures included in the literature and practiced in other places, did not exist at local level in the case study countries, but some local practices such as farmers’ annual fair could be an important addition to the inventory of potential adaptation measures. Local institutions have facilitated adaptation in different ways. They (1) lead and support unique adaptation practices suitable to the local context; (2) act as a catalyst to help people to adapt some practices by providing technical and material support; and (3) act as the bridge between local people and the governmental and non-governmental agencies. But several factors constrain the effectiveness of locally practiced adaptation measures. Thus, to enhance the adaptive capacity of households and the local community, it is necessary to: (1) improve the technical capacity of farmers; (2) create effective mechanisms for strengthening, promoting, and disseminating locally initiated efforts; (3) subsidize and improve access to credit services; (4) improve links between production and markets; and (5) establish effective mechanisms for coordination.

Natural climatic hazards like flood, an important hydro-geomorphic process of earth’s surface, have different regional and local impacts with significant socio-economic consequences. Similar was the case in Gujarat State, India during last week of June 2005. This study is about assessing the impact of Gujarat flood on river dynamics. It deals with extraction of water bodies information using radiance image and standard water indices i.e., Normalized Difference Water Index (NDWI) and Modified Normalized Difference Water Index (MNDWI) for pre- and post-flooding periods. Geomorphometric analysis along with drainage network extraction was done using two different Digital Elevation Models (DEMs) i.e., Advanced Space borne Thermal Emission and Reflection Radiometer (ASTER) and Shuttle Radar Topographic Mission (SRTM) and compared. Finally, depressions mapping and comparative analysis of magnitude and directional change of drainage networks was carried out. Results confirmed better accuracy of MNDWI in separating water bodies. The water bodies area increased by 10.4 % in post-flood monsoon compared to pre-flood monsoon and by 3.8 % in post-flood dry season compared to pre-flood dry season. Geomorphometric analysis indicated that ASTER DEM gave more values of maximum slope, average slope, and standard deviation as compared to SRTM. Aspects distribution algorithm did not work well in low relief regions. The drainage network generated using SRTMDEM was more accurate. The depressions identified were more susceptible to flood events. Change analysis of drainage network (deviating 100–300 m) indicated that 5.22 % points deviated between October, 2004 and 2005 and 3.18 % between February, 2005 and 2006.

The study examined whether access to spate irrigation leads to better nutrition outcomes. The results showed that there is an overall improvement in the study sites compared to the 2011 DHS study. As far as households with access to spate irrigation are concerned, weight-for-height z-scores indicated that 8.2% of the children had prevalence of global acute malnutrition; 8.2% of them had moderate acute malnutrition. None of the children had severe acute malnutrition. The weight-for-age results indicated that 27.5, 17.6 and 9.8% of the children showed prevalence of underweight, moderate underweight and severe underweight, respectively. The height-for-age z-scores showed 56.5, 30.8 and 21.7% of the children had prevalence of stunting, moderate stunting and severe stunting, respectively. On the other hand, households without access to spate irrigation indicated that as far as the weight-for-height z-scores of children are concerned, there were no children (boys and girls) with prevalence of global acute malnutrition; weight for-age z-score showed that 13.6, 10.2 and 3.4% of the children had prevalence of underweight, moderate underweight and severe underweight, respectively. The height-for-age z-scores showed that 45.5, 25.5 and 20.0% of the children had prevalence of stunting, moderate stunting and severe stunting, respectively. The anthropometric measures, thus, showed the nutritional outcomes of users were worse-off than of nonusers of spate irrigation. This happens in the face of better income and consumption expenditures, mainly nonfood, for users compared to nonusers. This underlines the importance of nutrition education alongside efforts to improve access to irrigation. Moreover, multisectoral collaborations are needed between the health, agriculture, water, social protection, education, gender and other sectors to improve the nutrition outcome of children.

Flood-based farming is among the potential options in ensuring access to water for crop and livestock production for small-scale farmers in the arid and semiarid lowlands of sub-Saharan Africa, and Ethiopia in particular. Flood-based irrigation while inexpensive is rooted in tradition in many rural communities which is in contrast to many other irrigation types which are unavailable (in terms of water source, technology or capacity) or are costly to develop. Spate irrigation has been practiced in different parts of Ethiopia for many decades, but it was only recently that it gained the government’s attention. This study was conducted through a review and informal discussion with the objectives of documenting the current status, trends and prospects of spate irrigation in the country and the associated challenges, taking cases of selected schemes in different regional states. The study revealed that spate irrigation is expanding either through improvement of traditional schemes or by developing new ones. Neither the traditional nor modern schemes are free of challenges. The traditional schemes suffer from floods that damage their diversion structures, while poor design and construction of diversion structures have led to the failure of new ones. A range of socio-technical improvements in the planning, implementation and operation of schemes is proposed, including the design of headworks and canals consistent with the size and nature of expected flows, structures to minimize sedimentation, building capacity of farmers and district officers, and monitoring and improving the management that currently adversely impacts the performance of the schemes. Consulting farmers at every stage of the development, and building the capacity of engineers to deal with the unique nature of spate flows are the most likely interventions to ensure successful agricultural production using spate irrigation.

Recharge dams in Oman detain floods to recharge groundwater. The impact of sedimentation on recharge at Wadi Sahalanowt Recharge Dam, in Salalah, Oman, was evaluated using field data and numerical modelling. Analysis of the thickness of sediments after flood events shows that maximum depositions were at the same locations after each event, coinciding with the lowest positions in the wadi. Numerical modelling suggests that the current practice of periodic removal of sediments will restore the storage capacity of the reservoir, but that ploughing or raking of the underlying native sedimentary rocks could be required to significantly improve infiltration rates.

This paper presents an algorithm for flood inundation mapping in the context of emergency response. Rapid satellite-based flood inundation mapping and delivery of flood inundation maps during a flood event can provide crucial information for decision-makers to put relief measures in place.With the development of remote sensing techniques, flood mapping for large areas can be done easily. The algorithm discussed here involves the use of shortwave infrared, near-infrared and green spectral bands to develop a suitable band rationing technique for detecting surface water changes. This technique is referred to as Normalized Difference Surface Water Index (NDSWI). The NDSWI-based approach produces the best results for mapping of flood-inundated areas when verified with actual satellite data. Analysis of results reveals that NDSWI has the potential to detect floodwater turbidity, which was verified using principal component analysis. The application of the technique is informative about flood damages, which are illustrated using the floods in Pakistan in 2010 as an example.

Increasing the productivity of smallholder agriculture holds the key to poverty reduction. The empirical literature is limited to ascertain the linkages and the implications for policy uptake in Ethiopia. We examine the impact of growth in agricultural productivity on household poverty dynamics in rural Ethiopia using a panel data set (1994–2009). Findings suggest that government policies aimed at reducing poverty should adopt a growth plus approach—designing policy interventions to support agricultural productivity growth, plus to protect assets and enhance market access for rural households in the country.

Riparian shallow groundwater and nutrient movement is important for aquatic and forest ecosystem health. Understanding stream water (SW)–shallow groundwater (GW) interactions is necessary for proper management of floodplain biodiversity, but it is particularly confounding in underrepresented semikarst hydrogeological systems. The Modular Three-Dimensional Finite-Difference Ground-Water Flow Model (MODFLOW) was used to simulate shallow groundwater flow and nutrient transport processes in a second-growth Ozark border forest for the 2011 water year. MODFLOW provided approximations of hydrologic head that were statistically comparable to observed data (Nash–Sutcliffe = 0.47, r2 = 0.77, root-mean-square error = 0.61 cm, and mean difference = 0.46 cm). Average annual flow estimates indicated that 82% of the reach length was a losing stream, while the remaining 18% was gaining. The reach lost more water to the GW during summer (2405 m3 day-1) relative to fall (2184 m3 day-1), spring (2102 m3 day-1), and winter (1549 m3 day-1) seasons. Model results showed that the shallow aquifer had the highest nitrate loading during the winter season (707 kg day-1). A Particle-Tracking Model for MODFLOW (MODPATH) revealed significant spatial variations between piezometer sites (p = 0.089) in subsurface flow path and travel time, ranging from 213 m and 3.6 yr to 197 m and 11.6 yr. The current study approach is novel with regard to the use of transient flow conditions (as opposed to steady state conditions) in underrepresented semikarst geological systems of the U.S. Midwest. This study emphasizes the significance of semikarst geology in regulating SW–GW hydrologic and nutrient interactions and provides baseline information and modeling predictions that will facilitate future studies and management plans.

In this research, the regional extreme-dry-spell frequency in the middle reaches of the Yellow River Basin (YRB) is studied by the L-moments method. The research area has been divided into three subregions (regions 1, 2 and 3), which have been identified as homogenous regions. The results of a goodness-of-fit test indicate that a generalized normal distribution is the optimal regional model for regions 1 and 2 whereas a generalized Pareto distribution is the optimal regional model for region 3. The return period analysis figures out that the maximum length-of-dry-spell (MxDS) values increase from south to north in the southern part and increase from northeast to southwest in the northern part of the middle reaches of the YRB under different return periods. The increments of quantiles of dry spell under different return levels indicate that drought risk in region 1 is higher than that in regions 2 and 3. The analysis of the occurrence day of MxDS shows that MxDS mostly occurred during winter of 1998 and spring of 1999 in most stations during the considered period. By comparing summer MxDS events, it can be found that mean MxDS values have slightly increased in regions 1 and 2 during the last five decades. The maximum mean MxDS values appeared in the 2000s for regions 1 and 2 and in the 1990s for region 3. The atmospheric circulation shows that the positive anomaly centre in the west of North China, negative anomaly centre in the east of North China and the strong western Pacific subtropical high led to the decrease of precipitation in North China during the summer of 1997.

Though there are surprisingly few estimates of the economic benefits of coordinated infrastructure development and operations in international river basins, there is a widespread belief that improved cooperation is beneficial for managing water scarcity and variability. Hydro-economic optimization models are commonly-used for identifying efficient allocation of water across time and space, but such models typically assume full coordination. In the real world, investment and operational decisions for specific projects are often made without full consideration of potential downstream impacts. This paper describes a tractable methodology for evaluating the economic benefits of infrastructure coordination. We demonstrate its application over a range of water availability scenarios in a catchment of the Mekong located in Lao PDR, the Nam Ngum River Basin. Results from this basin suggest that coordination improves system net benefits from irrigation and hydropower by approximately 3–12% (or US$12-53 million/yr) assuming moderate levels of flood control, and that the magnitude of coordination benefits generally increases with the level of water availability and with inflow variability. Similar analyses would be useful for developing a systematic understanding of the factors that increase the costs of non-cooperation in river basin systems worldwide, and would likely help to improve targeting of efforts to stimulate complicated negotiations over water resources.

This paper explores whether crop genetic engineering can contribute to addressing food security, as well as enhancing human nutrition and farming under a changing climate. The review is based on peer-refereed literature, using results to determine the potential of this gene technology. It also provides a brief summary of issues surrounding this genetic enhancement approach to plant breeding, and the impacts on farming, livelihoods, and the environment achieved so far. The genetic engineering pipeline looks promising, particularly for adapting more nutritious, input-efficient crops in the development of the world’s farming systems.

Well-targeted programs of conjunctive use of groundwater and surface water can help overcome the problem of both floods and droughts, or in other terms meet the water demands for domestic as well as irrigation needs during the dry season. Addressing this, a novel form of conjunctive use management has been developed that involves strategically recharging floodwater in upstream areas to boost small-scale groundwater irrigation and to protect floodaffected areas downstream. For this, choice of site is a crucial component to implement the approach. A method was devised using GIS tools using readily available data from secondary sources to arrive at a suitability index to rank prospects across the entire Ganges basin. This basin was chosen because it has a well-known history of devastating flooding events and water shortage in dry months and is one of the largest and most heavily populated river basins in the world. Numerical modelling is being applied to an area characterized as having high prospects to help to understand the interactions between the groundwater and surface water and the impact of floods on groundwater system. One of the main components to be identified from the model is the peak flows to be captured successfully for recharge. This utilisation of high flows by diverting from the rivers to storage structures introduced within the model will help to identify the potential to manage and reduce the flood impact. This model can help to decide on the size and placement of the structures to store water for maximum recharge and subsequently in watershed management. The relationship between floodwater storage and recharge, and the optimisation of these two processes can also be brought out. Opportunities for conjunctive use of water identified by mapping and the understanding gained from modelling is to be piloted out in one of these sites to establish technical and institutional feasibility with the view to promoting larger-scale implementation.

Climate change, water scarcity and food security are becoming increasingly important topics for the growing population of Africa. Due to a general lack of water resources in semi-arid and arid zones, water is an increasingly scarce input in agriculture. The impact of climate change exacerbates this situation further. Even in areas with abundant water resources, optimal use is hampered by insufficient infrastructure to capture these resources and knowledge on appropriate use. With the increased demand and competition for limited water resources the challenge is to increase agricultural production while reducing water consumption (“more crop per drop”). Solutions must be found to enable rural people to overcome poverty, and a start can be made by assisting in food production and water management to combat food insecurity. Local solutions must be adopted in which rural people’s access to new technologies increases. Therefore, smart and affordable technologies need to be adapted to customize farm management for this group of African farmers. Poor farmers need to access real-time information, be able to exchange and apply it: smart ICT (e.g. cell-phones backed up by the web) can play a fundamental role in the communication process.

Australia is a major food exporting country. Recent droughts reduced dryland farming production and the volume of water allocated to irrigated agriculture, with a resulting decline in aggregate agricultural production and exports. This paper analyses the possible impact of increased water scarcity on Australian agricultural production and the magnitude of subsequent impacts on global food security. Using the Australian Bureau of Statistics (ABS) data on land and water use coupled with a hydro-economic stochastic modelling approach, the impacts of reduced agricultural production in the southern Murray–Darling Basin, and more generally for Australia, are analysed. Changes in agricultural activity, reduction in agricultural exports and altered composition of products exported attributed to the severe 2000–2009 drought are also analysed to highlight the implications for global food security. The impact of climate change on food production is examined. The analysis shows that climate change, when modelled as the extreme case, along with other factors such as land use, will impact Australian food exports. Despite its relatively small contribution to total global food supply, Australia’s contribution to international trade in wheat, meat and dairy products is substantial and could affect global food prices. Furthermore, Australia’s agricultural exports are of disproportionate importance within the South- and South–East Asian and Oceania region, both in terms of volume and for strategic reasons. Adaptation along with investment in agriculture production is needed to maintain Australian agricultural production and enhance global food security.

While the bulk of research on crop water productivity (WP) focuses on static cross-section analysis, this research provides a spatio-temporal perspective. It estimates rice crop WP for 21 Bangladesh districts for 37 years; exploresWP variations among districts; and investigates causality involving WP, intensification and technological variables; and groundwater irrigation and depth. It breaks new grounds by probing these significant but unexplored issues.Technological diffusion was the key factor explaining inter-district WP differences. The impact of agricultural intensification on rabi (dry season) and kharif (wet season) crop WPs was positive and negative respectively. Dummy variables typifying policy transition negatively impacted on WPs for both kharif and overall crops. While rabi and kharif rice WPs grew with time, overall crop WP recorded the strongest growth. Rabi and overall WPs were lower in salinity- and drought-prone districts covering 33% of Bangladeshapos;s net cropped area (NCA). In 90% of Bangladeshapos;s NCA districts, technological diffusion caused WP. Causality existed between groundwater irrigation and depth in 60% NCA. Despite significant potential to increaseWP, increasing dependence on groundwater appears unsustainable. Widespread diffusion of HYVs in the kharif season, and development of salinity and drought-tolerant rice varieties could go a long way in sustaining rice WP.

Indian agriculture is the largest user of rainfall, surface and groundwater resources. Some of the large river systems feedings the canal systems and the groundwater aquifers, like the Indus, the Ganges, the Brahmaputra and their several tributaries have their origin in the Himalayas. A large part of the discharge of these river systems is fed through melting of the snow and glaciers. Although there is a lack of adequate scientific evidence on regional scales, a number of recent observational and modelling studies do suggest that the climate is changing. According to IPCC, the most significant consequences of climate change will be its impact on the hydrologic cycle, as already experienced in many parts of the world including India. Changes in precipitation intensity and duration will probably be the main factors altering the hydrologic cycle leading to more floods and droughts. Availability or scarcity of water will vary greatly depending on the region. The impact of climate change will be greater in India, where a majority of the rural population depends on agriculture for their livelihoods, and where agriculture is primarily dependent on the monsoons. Governments and communities have not been able to adequately address climate related challenges to peopleapos;s livelihoods that follow from changes in water availability, loss of crops and income with the occurrence of extreme weather events like floods and droughts. After a brief introduction to the importance of the subject, this paper describes in detail the impact of climate change on water resources in India, with special reference to the Indus and the Ganges River systems which constitute the major food basket of the country. The impacts of climate change on agriculture sector, including the rainfed agriculture have been presented. An analysis of the potential opportunities presented by enhanced flows for the surface systems and recharge for the groundwater aquifers has been presented and the paper concludes by presenting adaptive mechanisms in the agriculture sector and the important recommendations for improving institutional capacity, development and management of water resources, adaptation to floods and prevention and management of droughts.

By affecting evapotranspiration and influencing how water is routed and stored in a basin, forests, wetlands and floodplains play a crucial role in the hydrological cycle. Although they are widely attributed a major role in regulating flows (i.e., both attenuating floods and maintaining flow during dry periods), these services are rarely factored into the planning and management of water resources. One reason for the failure to include them is lack of understanding. Very often the extent to which natural regulating functions really occur is unclear. Against this background, this report describes a simple, pragmatic approach for quantifying the flow regulating functions of natural ecosystems. The method has been applied at 14 locations in the Zambezi River Basin.

Participatory research is increasingly recognized as being useful for conducting multiple activities in research for development projects. The co-learning environment created in participatory research helps to identify existing social and technological gaps, and develop possible solutions to improve the livelihoods of rural communities. This report describes a participatory approach used in the establishment and implementation of hydrometeorological monitoring networks in the Blue Nile River Basin of Ethiopia. The networks were established with the involvement of rural communities and other stakeholders to gain insights into the hydrological processes of the watersheds, in order to improve rainwater management strategies. Local people were involved in the day-to-day management and maintenance of the networks. The participatory approach proved beneficial for several reasons, not least, because it instilled trust and goodwill amongst the communities.

Groundwater drought denotes the condition and hazard during a prolonged meteorological drought when groundwater resources decline and become unavailable or inaccessible for human use. Groundwater drought risk refers to the combined physical risk and human vulnerability associated with diminished groundwater availability and access during drought. An integrated management support tool, GRiMMS, is presented, for the mapping and assessment of relative groundwater drought risk in the Southern African Development Community (SADC) region. Based on composite mapping analysis of regionwide gridded relative indices of meteorological drought risk, hydrogeological drought proneness and human groundwater drought vulnerability, the mapping results highlight consistent areas across the region with highest groundwater drought risk and populations in the order of 39 million at risk of groundwater drought at present. Projective climate-model results suggest a potentially significant negative impact of climate change on groundwater drought risk. The tool provides a means for further attention to the key, but neglected, role of groundwater in drought management in Africa.

Floods are one of the most common hazards in the world, affecting people’s lives and livelihoods. Flood hazard mapping and flood shelters suitability analysis are vital elements in appropriate land use planning for flood-prone areas. This paper describes application of Remote Sensing (RS) and Geographical Information Systems (GIS) in identifying flood hazard zones and flood shelters and are therefore important tools for planners and decision makers. The purpose of this article is to describe a simple and efficient methodology to accurately delineate flood inundated areas, flood-hazard areas, and suitable areas for flood shelter to minimize flood impacts. Possible extent of flooding and suitable location flood shelter sites were modeled and mapped for Sindh Province in Pakistan, using the software ArcGIS model builder. The output was validated using inundation maps based on flood events that took place in 2010 in Pakistan. These were mapped using object-based image analysis (OBIA) implemented in eCognition software. The catastrophic flood of 2010 inundated a total area of 7579 km2, while the modeled result indicated the hazard area to be 6216 km2 out of 46138 km2. Discrepancies in modeled and mapped results are insignificant and acceptable considering the manual flood management interventions which are beyond the capability of models to represent. Thus, this method is robust enough to develop flood hazard zoning maps and map shelter sites for flood management.

Floods are one of the most frequent and widespread natural hazards in the world. A recent example is the 2011 floods in three of the four Lower Mekong Basin Countries (Thailand, Cambodia and Vietnam) that caused severe impacts in terms of loss of life and damage to infrastructure. Several studies have highlighted the increasing importance of developing spatio-temporal flood hazard databases to understand flood dynamics more systematically at a range of spatial scales within South East Asia (SEA). This study is proceeding on two distinct fronts: the first focusses on ranking and prioritization of impacts across SEA, whilst the other examines an approach to flood monitoring that evaluates the feasibility of implementing possible mitigation strategies that still provide for the degree of flow variability needed to maintain ecosystems. Firstly, long-term time-series data from multiple sources (e.g. EM-DAT, DFO, Sentinel Asia) was used in identifying flood hotspots including their frequency, intensity/severity and societal impacts. This will also help in evaluating and improving hydrological modeling predictions and provide better information for more effective flood hazard, flood risk and preparedness studies. Flood hotspots were further investigated taking into account of agricultural extent loss, populations at risk and economic loss. The results from the hotspot analysis suggest more climate risk investments are needed to minimize risk and are likely to have the biggest payoff in terms of reduced losses. The nature of those investments and the associated cost-benefits are being revealed. Secondly, a new approach is being developed for flood monitoring from time-series MODIS data acquired from 2000 to 2012. This approach will help in identifying basin to regional-scale temporal changes in inundated area; duration of inundation cycles between large-medium-small scale floods. Thus satellite-based mapping of flood risks areas will help in identifying prospective areas for floodwater harvesting in the upstream areas to reduce negative impacts downstream.

In this article, we explore the ways in which people in the Ethiopian Gambela region dealt with the extreme flood that occurred in 2007, with specific attention to the associated loss and damage, i.e., the impacts that people were not able to avoid through preventive and coping measures. We found that all of the 431 surveyed households took preventive measures such as the construction of boundary walls, harvesting premature crops and digging drainage ditches to divert the flood away from croplands. However, these could not prevent widespread negative effects such as damage to houses and crops, the outbreak of diseases, and loss of livestock. To deal with the adverse effects, 50% of the respondents relied on the help of relatives, neighbours or friends for food and money. Such assistance appeared crucial. People were, however, worried about over-using their social networks, especially with floods occurring more regularly. Widening peopleapos;s agricultural and non-agricultural options, for example through investments in micro-finance services and irrigation systems, will help to increase their coping capacity.

This article focuses on cooperative adaptation strategies at the community, water user association, district, and national levels along the Khojabakirgansai, a small transboundary tributary of the Syr Darya in Kyrgyzstan and Tajikistan. Data were collected in the basin through in-depth expert interviews, site visits, and household surveys, and were triangulated with climate change data from the available literature. Basin inhabitants cooperate on extreme events that are exacerbated by climate change, including water scarcity, droughts, and flash floods. Water demand and efficiency are key issues driven by population growth, expansion of croplands, and deteriorating canal infrastructure. Lessons learned can be considered in other small transboundary tributaries in the Ferghana Valley and Central Asia, which demonstrate how, despite the international level of tension on water issues in the region, local communities can find solutions. Cooperation, however, does not always improve the basin environment or living standards, and is likely to be strained in the coming decades by climate and population trends, among other issues.

By comparing the successful story of a hydrodynamic model (based on its contribution to policy changes, management options and livelihood improvement) with other modelling cases in the Mekong River Delta, five success factors are identified. These are (1) simulated phenomena relevant to and understandable by policy makers; (2) response to the needs of policy setting; (3) developed and handled by national modellers with direct links to the policy process; (4) availability of input data; and (5) long application history. These success factors provide higher opportunities for engaging modelling activities with policy setting.

Project Preparatory Technical Assistance 7883-NEP

In recent years, large-scale agricultural investment projects have increased in sub-Saharan Africa as a result of the growing appetites of local and international investors for land resources. Research has so far mainly focused on land issues, but the water implications of these land deals are starting to surface. Taking the Office du Niger (ON), in Mali, as a case study, we show that while around 100,000 ha is currently being cultivated, mostly by smallholders, a total of 600,000 ha of land has been allocated in the past ten years to investors in large-scale farming. This process has largely bypassed the official procedure established by the ON at regional level. The allocation of new lands has shifted to the national level, with an attempt to recentralize the management of land deals and associated benefits at the highest level, despite contrary efforts by foreign donors to strengthen the ON. This article describes the complex allocation process based on apos;behind-closed-doorsapos; negotiations. It then analyses the implications of the land deals on water issues by focusing on the strategies of actors to limit the risk of future water shortages, the current and expected difficulties in water management and allocation, and the emerging spatial and social redistribution of benefits and risk that signals a process of water grabbing.

Increasing temperatures and declining rainfall patterns as well as increasing frequency of extreme climate events such as droughts and floods are the expected future weather patterns within the tropics. Africa, particularly Southern Africa, is projected to be the region most vulnerable to the impacts of climate variability and change especially in agriculture and water. This has dire consequences as most people in Southern Africa depend on agriculture for their livelihoods. While much of climate change studies have been done at global scale, the impacts of climate change and variability will be felt locally at household, community, national and regional levels. In most cases daptation occurs at local level in ways that are usually unnoticed and unaided by national governments or international organisations. This paper down-scales the vulnerability of and adaptive capacity to climate change and variability to local level (household, community, national and regional) applying the Household Economy Approach (HEA). The focus is on local dimensions of climate change impact on water availability and agriculture productivity in Southern Africa, but taking only a sample of the region. In addition, an assessment of the factors that determine the capacity of local communities to deal with current and future climate changes and variability is made. Adaptive measures are also recommended, paying special attention to the role of local institutions in adapting to climate change. This paper emphasises the importance of ensuring that farmers have access to relevant knowledge and information on the effects of climate variability and change in order to enhance their adaptive capacity.

This paper develops a hydro-economic optimization modeling framework to assess the economic consequences and potential trade-offs of various infrastructure development and policy pathways in the Nam Ngum Basin (Lao PDR). We considered whether large shifts in water resource demands in a relatively water abundant basin could induce meaningful economic trade-offs among water uses, including hydropower generation, irrigation expansion, flood control, and transboundary water transfer objectives. We constructed a series of sensitivity scenarios under dry, average, and wet hydrologic conditions with varying levels dam development, irrigated agricultural expansion, agricultural returns, flood control storage restrictions, and water diversions to Northeast Thailand. We also considered how flows into the Mekong would be affected by these collective developments. In general, results indicate that tradeoffs between hydropower production, irrigation, and flood control are modest. Hydropower and agricultural expansion are found to be complimentary under high levels of water availability, even with the most ambitious level of irrigation expansion. Allowing for flood control by maintaining reduced storage levels in the reservoir that is largest and furthest downstream on the Nam Ngum (NN1) has a minimal effect on economic output and decreases total system hydropower by less than 1%. However, economic outcomes are highly dependent on water availability and economic returns to irrigated agriculture. System hydropower was greatly reduced, and inter-basin transfer projects induced large economic costs under dry conditions. These results on seasonal impacts illustrate the importance of accounting for climate variability and potential hydrologic change in cost-benefit analysis of infrastructure projects, even in watersheds that are relatively water abundant.

Rice submergence is the condition by which the water level rises above the rice crop canopy. In general, rice plant response to submergence is to elongate its shoots above the rising water level. This costs in energy and eventually has a direct impact in terms of reducing yields. A specific gene, called Sub1, when introgressed into popular rice varieties by Marker Assisted Back-crossing, nearly stops the natural elongation process and permits a given local rice variety to sustain submerged conditions for a generally recognized period of about 2 weeks. Plant breeders now look for well-identified and location-accurate submergence areas in order to disseminate such improved local rice varieties. Remote sensing is proposed to provide surface water maps at high temporal resolution, determining a percentage of occurrences of surface water for a given pixel. Occurrence is defined as the count of days of identified surface water within a given period, returned in a percentage on that period. Rice area maps and knowledge of crop calendars are proposed to add to the assessment of submergence prone areas in two study areas, the Northeastern Thailand and Nueva Ecija in North Central Philippines.

Ecosystem integrity as well as the goods and services offered by the rivers in India are getting adversely affected by changes in quantity, quality and flow regimes. Growing water abstractions for agriculture, domestic, industrial and energy use are leaving many rivers running dry, while others are becoming severely polluted. The mighty Ganga is no exception. During its 2,525 km journey from Gangotri to Ganga Sagar, there are complex, nested sets of challenges that threaten the very existence of the holy river revered by millions of Indians. In the upper Himalayan reaches, the flow in the river is vulnerable to water abstractions by hydropower projects, both existing and proposed. From the time the river enters the plains, abstractions for agriculture, urban and industrial uses leave the river lean and polluted. As the riverapos;s dynamics have been altered by diversions and inefficient use, the freshwater flow has reduced, leading to a reduction in the river’s assimilative capacity. As the river makes its way to the sea, and more pollution is added to the lean flows, the stress on the Ganga increases. Climate change is adding another set of complexities to the problems of the Ganga and to the hundreds of millions of people who depend on the river and its basin.

Located on the Bahr el Jebel in South Sudan, the Sudd is one of the largest floodplain wetlands in the world. Seasonal nundation drives thehydrologic, geomorphological, and ecological processes, and the annual flood pulse is essential to the functioning of the Sudd. Despite the importance of the flood pulse, various hydrological interventions are planned upstream of the Sudd to increase economic benefits and food security. These will not be without consequences, in particular for wetlands where the biological productivity, biodiversity, and human livelihoods are dependent on the flood pulse and both the costs and benefits need to be carefully evaluated. Many African countries still lack regional baseline information on the temporal extent, distribution, and characteristics of wetlands, making it hard to assess the consequences of development interventions. Because of political instability in Sudan and the inaccessible nature of the Sudd, recent measurements of flooding and seasonal dynamics are inadequate. Analyses of multitemporal and multisensor remote sensing datasets are presented in this paper, in order to investigate and characterize flood pulsing within the Sudd wetland over a 12-month period. Wetland area has been mapped along with dominant components of open water and flooded vegetation at five time periods over a single year. The total area of flooding (both rain and river fed) over the 12 months was 41 334 km2, with 9176 km2 of this constituting the permanent wetland. Mean annual total evaporation is shown to be higher and with narrower distribution of values from areas of open water (1718 mm) than from flooded vegetation (1641 mm). Although the exact figures require validation against ground-based measurements, the results highlight the relative differences in inundation patterns and evaporation across the Sudd.

Wetlands and forests have strong effects on hydrological processes by changing the rate of evaporation, transpiration, and flow routing in a basin, which affects basin water management such as dam operations. This study aims to assess the flow regulating functions of wetlands and forests using a flow duration curve (FDC) approach. We firstly identify wetlands and forests which are gauged both upstream and downstream. Reference conditions were then established using nearby sub-watersheds that contain few/no wetlands/forests. By transferring reference flows to the target sites and comparing the FDCs for with and without wetland/forest conditions we then assess the hydrological impacts on flood attenuation and base flow maintenance. Results of a floodplain wetland suggest that it decrease flood flows and increase low flows. The extent of this function could be quantified which gives useful indications for water resources planning and management.

Effective implementation of participatory environmental governance faces a number of challenges, including the need for a