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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.

Exposure to metals has been hypothesized as possible cause of chronic kidney disease of unknown cause (CKDu) in Sri Lanka; however, evidence is inconclusive. We measured the concentrations of nephrotoxic metals (As, Pb, and Cd), as well as Se in rice (a staple grain in Sri Lanka) and other grains consumed in CKDu endemic and non-endemic regions using Inductively Coupled Mass Spectrometry (ICP-MS). Our results showed comparable mean concentrations (in g/kg) of 24.518, 7.36.4, and 14.215 for As, Pb, and Cd, respectively, in rice from endemic regions and 17.74.7, 12.76.8, and 17.816 in rice from non-endemic regions. Selenium concentrations (in mg/kg) were 0.050.02 in rice cultivated in both endemic and non-endemic regions. Arsenic and Cd concentrations were significantly higher in rice compared to other grains, which themselves had higher Se than rice. All samples were below the Codex standards established for Cd (400 g/kg for rice; 100 g/kg for cereal grains), Pb (200 g/kg) and inorganic As (200 g/kg) for white rice. Our findings show that dietary exposure to low levels of As, Pb, Cd, and inadequate Se in staple grains cannot be clearly linked to CKDu, suggesting that the disease could be multifactorial. Additional research is needed to determine the contribution of other risk factors such as lifestyle habits and heat stress to plan preventive strategies for reducing CKDu health cases in Sri Lanka.

Sustainable agriculture focuses using agricultural resources with minimum possible negative environmental externality to produce more food. The present study reports the environmental and health risks associated with the use, management and handling of agrochemical in the Central Rift Valley, Ethiopia. Six Woredas (or districts) covering both upstream and downstream areas and major ecosystems were selected. Data were collected using focus group discussion, key informant interviews, field observation and literature review. Pesticide Risks in the Tropics for Man, Environment and Trade tool was used to analyse data. Results indicated that local community’s awareness on use, handling and management of pesticides was low. Applications of insecticides, fungicides and herbicides polluted surface water systems and affected aquatic animals and plants with different level of risk (i.e. from no or insignificant risk to acute and chronic levels). The level of risks of using agrochemical on aquatic animals, human and the environment increased when the agricultural practices changed from good to non-good practices (i.e. increasing frequency of application). The types of agrochemicals determined the levels of risks on aquatic animals, human and the environment. For example, copper hydroxide and Lambda pose high risk, whereas Chlorpyrifos poses possible risk on fish under good agricultural practices. Also, the results indicated that the level of risks of using agrochemicals on fish and aquatic vertebrates was high for few pesticides (e.g. Chlorpyrifos) under both good and bad agricultural practices. The results of the present study support decision makers, practitioners and farmers to put corrective measures when importing agrochemicals, provide targeted risk management schemes including training on safety measures and screen agrochemicals on the market, respectively.

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.

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.

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.

River systems originating from the Upper Indus Basin (UIB) are dominated by runoff from snow and glacier melt and summer monsoonal rainfall. These water resources are highly stressed as huge populations of people living in this region depend on them, including for agriculture, domestic use, and energy production. Projections suggest that the UIB region will be affected by considerable (yet poorly quantified) changes to the seasonality and composition of runoff in the future, which are likely to have considerable impacts on these supplies. Given how directly and indirectly communities and ecosystems are dependent on these resources and the growing pressure on them due to ever-increasing demands, the impacts of climate change pose considerable adaptation challenges. The strong linkages between hydroclimate, cryosphere, water resources, and human activities within the UIB suggest that a multi- and inter-disciplinary research approach integrating the social and natural/environmental sciences is critical for successful adaptation to ongoing and future hydrological and climate change. Here we use a horizon scanning technique to identify the Top 100 questions related to the most pressing knowledge gaps and research priorities in social and natural sciences on climate change and water in the UIB. These questions are on the margins of current thinking and investigation and are clustered into 14 themes, covering three overarching topics of “governance, policy, and sustainable solutions”, “socioeconomic processes and livelihoods”, and “integrated Earth System processes”. Raising awareness of these cutting-edge knowledge gaps and opportunities will hopefully encourage researchers, funding bodies, practitioners, and policy makers to address them.

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.

The severity of the climate challenge requires a change in the climate response, from an incremental to a more far-reaching and radical transformative one. There is also a need to avoid maladaptation whereby responses to climate risk inadvertently reinforce vulnerability, exposure and risk for some sections of society. Innovative technological interventions are critical but enabling social, institutional and governance factors are the actual drivers of the transformative process. Bringing about this transformation requires inter- and transdisciplinary approaches, and the embracing of social equity. In this Perspective, we unpack what this means for agricultural research and, based on our collective experience, we map out a research agenda that weaves different research components into a holistic and transformative one. We do not offer best practice, but rather reflections on how agricultural research can more readily contribute to transformative adaptation, along with the personal and practical challenges of designing and implementing such an agenda.

Chromium (Cr) contamination in paddy soil-rice systems threatens human health through the food chain. This study used a new dataset of 500 paddy soil and plant tissue samples collected in the rice-growing regions of Sindh and Punjab Provinces of Pakistan. Overall, 97.4% of grain samples exceeded the Cr threshold values of 1.0 mg kg-1, determined by the China National Food Standard (CNFS). The Cr in paddy soil, 62.6% samples exceeding the China natural background threshold value (90 mg kg-1) for Cr concentration in paddy soil, and lower than the (pH-dependant gt; 7.5 threshold value for Cr 350 mg kg-1) as determined by China Environmental Quality Standards (EQSs) for paddy soil (GB15618-2018). Geographically weighted regression (GWR) modelling showed spatially nonstationary correlations, confirming the heterogeneous relationship between dependent (rice grain Cr) and independent paddy soil (pH, SOM, and paddy soil Cr) and plant tissue variables (shoot Cr and root Cr) throughout the study area. The GWR model was then used to determine the critical threshold (CT) for the measured Cr concentrations in the paddy soil system. Overall, 38.4% of paddy soil samples exceeding CT values confirm that the paddy soil Cr risk prevails in the study area. Furthermore, the GWR model was applied to assess the loading capacity (LC), the difference between the CT, and the actual concentration of Cr in paddy soil. Loading capacity identified potential paddy soil Cr pollution risk to rice grain and assessed the risk areas. Overall LC% of samples paddy soil Cr risk areas grade: low-risk grade I (34.6%); moderate-risk grade II (15.8%); high-risk grade III (11.2%); and very high-risk grade IV (38.4%) have been assessed in the study area. The human health index, total hazard quotient (THQ 1), indicates no potential health risk originating from Cr exposure to the population. However, the excess Cr level in paddy soil and rice grain is still a concern. The current studyapos;s results are also valuable for the national decision-making process regarding Cr contamination in the paddy soil-rice system.

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.

This study is oriented towards the investigation of the spatiotemporal variability of the lightning activity over the railway network in Sri Lanka using -lightning data from 1998 to 2014 that were downloaded from the database of Lightning Imaging Sensor (LIS) onboard NASA’s Tropical Rainfall Measuring Mission (TRMM). The study has also been extended to study the lightning activity over the proposed suburban railway electrification network. GIS was used to conduct an annual and seasonal analysis of the railway network, which consists of nine major railway lines, to identify vulnerable stations and segments. The average annual lightning flash density over a 1447 km-long railway network of Sri Lanka varies between 5.08–16.58 flashes/(km2 year). The railway lines run across the western and southern regions of the country have been identified as being in areas with higher lightning activity. In comparison to other railway lines, the Kelani Valley line in the Colombo district and Colombo-Maradana to Polgahawela segment of the Mainline are particularly vulnerable to lightning activity. These areas have also been recognized as regions with higher population density. The proposed 102 km long railway electrification network in Sri Lanka is also within higher population density segments, with higher lightning flash density values between 10.55–16.53 flashes/(km2 year). As a result, to improve the operational efficiency of the proposed electrification network, a fully coordinated lightning protection system in accordance with the findings of this study is strongly suggested.

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.

Across several coastal areas in Morocco, groundwater is the strategic source of irrigation. In this work, a database of thirteen Moroccan coastal aquifers was used to assess groundwater for agriculture purposes, as well as to highlight the process responsible of the degradation of groundwater resource quality in Moroccan coastal areas. According to electrical conductivity parameter, the results show that 92% of the collected samples were not suitable for irrigation uses. This situation is due to seawater intrusion and water–rock interaction processes, in addition to intensive agriculture activities and the introduction of domestic and industrial wastewater without any treatment. In order to control the impact of groundwater salinity on agriculture, management plans are proposed.

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.

In recent decades, antibiotic resistance (AR) has become a public health concern fuelled by increasing antibiotic consumption in many societies. Aquatic environments play a crucial role in AR development and spread where they receive antibiotics, antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARGs) from a number of sources such as agriculture, aquaculture and wastewater treatment plants. Modelling is an increasingly important approach to understanding AR in aquatic environments and helps identify resistance patterns of emerging concern, evaluate fate and transport, and assess infection risks as well as look into their management in the future. However, current water quality models need to be improved to deal with the development and spread of AR. Prioritising the development of fate and transport models for AR could provide insights into bacterial evolution and help manage environmental pollution. This article provides a conceptual water quality modelling framework through a concise review of methods and approaches that can be used to model and evaluate AR in aquatic environments at the watershed scale. The key steps that need to build a framework include identifying sources and loadings, modelling the fate and transport of ARB and quantifying associated risks to humans and animals. Developing modelling scenarios and management strategies based on the framework could also contribute to achieving Sustainable Development Goals 3 (good health and well-being) and 6 (clean water and sanitation).

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.

Climate change and associated extreme weather events directly impact the functioning and sustainability of food systems. The increasingly erratic onset of seasonal rainfall and prolonged heat stress during growing seasons are already causing crop losses. As of late 2021, for example, Madagascar’s three successive seasonal droughts had put 1.35 million people at risk of the world’s first climate-change-induced famine. In the United States, the number of days between billion-dollar weather-related disasters has fallen from more than 80 in the 1980s to just 18 in recent years. Without adequate preparation, these weather hazards disrupt food supply chains by interrupting production and cause problems farther along these chains by raising costs and prices of processing, storage, transport, retail, and consumption and reducing business revenues.

Fish inhabiting freshwater environments are susceptible to the ingestion of microplastics (MPs). Knowledge regarding MPs in freshwater fish in South Africa is very limited. In this study, the uptake of MPs by common carp (Cyprinus carpio) in the Vaal River in South Africa was assessed. MPs were detected in all of the twenty-six fish examined, 682 particles of MPs were recovered from the gastrointestinal tracts of the fish with an average of 26.23 12.57 particles/fish, and an average abundance of 41.18 52.81 particles/kg. The examination of the physical properties of MPs revealed a predominance on fibers (69%), small-sized particles of less than 0.5 mm (48%), as well as prevelance of coloured MPs (94%), mostly green, blue, and black. Using Raman Spectroscopy, the following plastic polymers were identified: high density polyethylene (HDPE), low density polyethylene (LDPE), polypropylene (PP), polyethylene terephthalate (PET), and polytetrafluoroethylene (PTFE). To the best of our knowledge, this study, is the first to report MPs uptake by freshwater biota in the Vaal River using common carp as a target organism. It provided evidence of MP contamination in the Vaal.

The use of polluted water to irrigate is an increasing problem in the developing world. Lebanon is a case in point, with heavily polluted irrigation waters, particularly in the Litani River Basin. This study evaluated the potential health risks of irrigating vegetables (radishes, parsley, onions, and lettuce) using three water sources (groundwater, river water, and treated wastewater) and three irrigation methods (drip, sprinkler, and surface) over two growing seasons in 2019 and 2020. Water, crop, and soil samples were analyzed for physicochemical parameters, pathogens, and metals (Cu, Cd, Ni, Cr, and Zn). In addition, the bioaccumulation factor, estimated dietary intakes, health risk index, and target hazard quotients were calculated to assess the health risk associated with metal contamination. The study showed that, for water with less than 2 log E. coli CFU/100 mL, no pathogens (Escherichia coli, salmonella, parasite eggs) were detected in irrigated vegetables, irrespective of the irrigation method. With over 2 log E. coli CFU/100 mL in the water, 8.33% of the sprinkler-and surface-irrigated vegetables, and 2.78% of the drip-irrigated root crops (radishes and onions), showed some degree of parasitic contamination. E. coli appeared only on root crops when irrigated with water having over 3 log CFU/100 mL. The concentrations of most metals were significantly lower than the safe limits of the FAO/WHO of the Food Standards Programme Codex, except for zinc and chromium. The trends in the bioaccumulation factor and the estimated dietary intakes of metals were in the order of Cu lt; Cd lt; Ni lt; Cr lt; Zn. The target hazard quotient values for all metals were lower than 1.0. Under trial conditions, the adoption of drip irrigation with water with less than 3 log E. coli CFU/100 mL proved to be safe, even for vegetables consumed raw, except for root crops such as onions and radishes that should not be irrigated with water having over 2 log E. coli CFU/100 mL. Treated wastewater had no adverse effect on vegetable quality compared to vegetables irrigated with other water sources. These results support efforts to update the Lebanese standards for water reuse in agriculture; standards proposed in 2011 by the FAO, and currently being reviewed by the Lebanese Institution of Standards. This research will inform a sustainable water management policy aimed at protecting the Litani River watershed by monitoring water quality.

Sub-Saharan Africa faces unprecedented disasters, with climate change expected to exacerbate the frequency and severity of unpredictable and stressful catastrophic events. Unlike developed nations, reconstruction in developing nations is hindered by resource constraints, with certain communities potentially experiencing multiple and enduring effects of disasters. Despite the potential danger of such cumulative community disaster exposure on mental health (e.g. depression), large-scale population-level evidence for the region is limited. We investigated the association between exposure to cumulative disaster and the first onset of depression in a nationally representative survey in South Africa. We used panel data from the South African National Income Dynamics Study (SA-NIDS) from 2008–2017, consisting of 17,255 adult study participants who were depression free at baseline. Risk of first depression onset between individuals exposed and unexposed to community disaster was measured, accounting for multiple disaster exposure over time by fitting generalized estimating equation (GEE) regression models. Data on the geographic location of disasters were obtained from the South African government gazette, and mapped with the government delineated SA-NIDS households’ locations. Of the sampled individuals, 2,986 were exposed to disaster during the study duration (17.3%). Increased cumulative community disaster was significantly associated with the likelihood of depression onset (adjusted relative risk [aRR] = 1.20, plt;0.01, 95% CI: 1.09–1.33), even after controlling for socio-demographic factors. In sub-group analyses, greater likelihood of depression onset was found among females [but not in men] (aRR = 1.23, plt;0.01, 95% CI: 1.09–1.38), Black African [but not in other population group] (aRR = 1.21, plt;0.01, 95% CI: 1.09–1.36), lower education attainment group [but not in tertiary and above educational attainment group] (aRR = 1.20, plt;0.01, 95% CI: 1.08–1.33), and lower income attainment group [but not in the top income quartile group] (aRR = 1.24, plt;0.01, 95% CI: 1.11–1.38), due to cumulative community disaster. Although cumulative community disaster exposure was significantly associated with the first onset of depression, its negative impact may be more pronounced among individuals considered chronically socially vulnerable (i.e. the groups above) in South Africa. Given that many individuals in South Africa rely on social, food parcel relief, and health services from government/public sector, timely access to community-based supportive intervention is needed for disaster survivors, prioritizing socially vulnerable groups to help mitigate problems associated with mental health challenges.

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.

This paper investigates the impact of erratic rainfall and related water problems on agricultural productivity. The paper also aims to shed light on the conceptual importance of understanding the incidence and impacts of rainfall shocks for choosing feasible agricultural water risk management strategies both at household and policy levels. To achieve these goals we develop a conceptual framework, use national representative data from Zambia’s crop estimates survey for 2017/2018 farming season, employ fixed effects regression approach, and find that dry spells, excessive floods, incidence of water logging are all detrimental to crop productivity. The crop-based equations also reveal the differential impacts of the rainfall shocks on different crops. Since the effect of water factors including dry spells, floods and water logging on agricultural productivity is dependent on the crop types, it is important for the Zambian government as well as other countries to take this into account when planning and implementing strategies for agricultural water risk management.

Many communities in South Asia are highly exposed and vulnerable to weather and climate hazards, and climate services play an important role in managing present and future climate risks. Here we take stock of ongoing climate service activities under the Asia Regional Resilience to a Changing Climate (ARRCC) Met Office Partnership programme. ARRCC aims to strengthen climate resilience in South Asia through co-producing weather and climate services, building institutional capacities, and enhancing coordination across the region and in focal countries: Afghanistan, Bangladesh, Nepal and Pakistan. We identify what is working well and challenges that remain in the provision and uptake of climate services, focusing on examples of applying seasonal forecasts, sea-level rise projections, and extreme rainfall information for hydropower decisions. We demonstrate the value of building equitable and sustainable partnerships, enhancing knowledge sharing, strengthening evaluation, and approaches that combine model information within a decision-centred framework. Based on experiences in ARRCC, we find that climate information alone is often insufficient to meet decision-maker needs, and discuss the role for new climate impact services that integrate climate information with knowledge and tools on climate impacts and vulnerabilities.

In Addis Ababa and its environs, most urban wastewater is discharged into rivers without treatment. This study related urban wastewater characteristics to the prevalence of faecal, antibiotic resistant, and potentially pathogenic bacteria in rivers of the Akaki catchment across six locations, for the dry and wet season. Spatiotemporal variation in bacterial hazards across the catchment was up to 6 log10 units. Cooccurrence of sewage pollution marker gene HF183 in all river samples testing positive for the Vibrio cholerae marker gene ompW, and high levels of these two genes in untreated wastewater, identified human sewage as the likely source of Vibrio cholerae hazards in the catchment. Levels of the marker genes rodA for E. coli, HF183 for human host associated Bacteroides, ciaB for Arcobacter, and ompW for Vibrio cholerae were all higher in the dry season than in the wet season. Marker gene gyrB for Pseudomonas aeruginosa was not detected in the samples. From the sequencing data, notable bacterial genera in the dry season included wastewater pollution indicators Arcobacter and Aeromonas, whereas soil erosion may explain the greater prominence of Legionella, Vicinamibacter, and Sphingomonas during the wet season. Except for the most upstream location, all faecal coliform (FC) counts exceeded WHO standards of 1000 CFU/100 mL for unrestricted irrigation. Concerningly, 0.6–20% of FC had ESBL producing antimicrobial resistance traits. In conclusion, multiple bacterial hazards were of concern for river water users in the Akaki catchment, and elevated in the dry season, when the river water is being used for irrigation of vegetable fields that supply the markets of Addis Ababa. This reflects inadequate treatment and limited dilution of urban wastewater by the natural river flows during periods of low rainfall.

Climate-related hazards can lead to agricultural losses and affect local and wider food supply via food trade. This study estimates the potential for adverse effects of climate hazards on food supply across Indian States and Union Territories (hereafter ‘states’) by quantifying climate hazard risks. Risks were estimated using the most recent data available on hazard presence, vulnerability, and volume of per capita food supply that is exposed to hazards. Historical (2000–2020) climatological and geological data sourced from meteorological stations and satellite imagery were used to estimate the state-level presence of eight climate-related hazards (droughts, forest fires, floods, extreme rainfall, landslides, cyclones, extreme temperatures, sea level rise). For each state and hazard type, we distinguished between risk to food supply produced in the state and the risk to food supply imported from other states. The source of food supply was estimated from a supply and demand balance model for 30 major food items that uses government data from 2011–12. We found that climate hazard risks to food supply vary across states and by hazard type. The largest climate hazard risks to state food supply are in Bihar, Madhya Pradesh, and Assam, where the majority of risk is to locally produced supply. Food supply in each state is at risk to all eight climate hazards via food imports from other Indian states. For 14 states, the climate hazard risk is greater for imported food supply than for locally produced supply. Just five states contribute to more than half of the climate hazard risk in interstate food trade. The findings indicate that climate-related hazards in Indian states could have potentially adverse effects on national food supply, affecting both local production and interstate trade. For policy-makers, these climate hazard risks identify potential priorities for enhancing food system resilience to mitigate impacts on local and national food security.

Globally, the use of untreated, often diluted, or partly treated wastewater in agriculture covers about 30 million ha, far exceeding the area under the planned use of well-treated (reclaimed) wastewater which has been estimated in this paper at around 1.0 million ha. This gap has likely increased over the last decade despite significant investments in treatment capacities, due to the even larger increases in population, water consumption, and wastewater generation. To minimize the human health risks from unsafe wastewater irrigation, the WHO’s related 2006 guidelines suggest a broader concept than the previous (1989) edition by emphasizing, especially for low-income countries, the importance of risk-reducing practices from ‘farm to fork’. This shift from relying on technical solutions to facilitating and monitoring human behaviour change is, however, challenging. Another challenge concerns local capacities for quantitative risk assessment and the determination of a risk reduction target. Being aware of these challenges, the WHO has invested in a sanitation safety planning manual which has helped to operationalize the rather academic 2006 guidelines, but without addressing key questions, e.g., on how to trigger, support, and sustain the expected behaviour change, as training alone is unlikely to increase the adoption of health-related practices. This review summarizes the perceived challenges and suggests several considerations for further editions or national adaptations of the WHO guidelines.

Access to sufficient clean water is important for reducing the risks from COVID-19. It is unclear, however, what influence COVID-19 has had on water insecurities. The objective of this study was to assess the associations between COVID-19 control measures and household water insecurities. A survey of 1559 individuals living in vulnerable communities in five countries (Cambodia, Laos, Myanmar, Thailand, Vietnam) showed that increased needs for clean water to wash hands or facemasks made it more likely a person was water insecure along those dimensions. Water insecurities with respect to handwashing and drinking, in turn, made adoption of the corresponding good practices less likely, whereas in the case of washing facemasks there was no association. Water system infrastructure, environmental conditions such as foods and droughts, as well as gender norms and knowledge, were also important for water insecurities and the adoption of good practices. As domestic water insecurities and COVID-19 control measures are associated with each other, efforts should therefore be directed at identifying and assisting the water insecure at high risk when COVID-19 reaches their communities.

Environmental exposure to active pharmaceutical ingredients (APIs) can have negative effects on the health of ecosystems and humans. While numerous studies have monitored APIs in rivers, these employ different analytical methods, measure different APIs, and have ignored many of the countries of the world. This makes it difficult to quantify the scale of the problem from a global perspective. Furthermore, comparison of the existing data, generated for different studies/regions/continents, is challenging due to the vast differences between the analytical methodologies employed. Here, we present a global-scale study of API pollution in 258 of the world’s rivers, representing the environmental influence of 471.4 million people across 137 geographic regions. Samples were obtained from 1,052 locations in 104 countries (representing all continents and 36 countries not previously studied for API contamination) and analyzed for 61 APIs. Highest cumulative API concentrations were observed in sub-Saharan Africa, south Asia, and South America. The most contaminated sites were in low- to middle-income countries and were associated with areas with poor wastewater and waste management infrastructure and pharmaceutical manufacturing. The most frequently detected APIs were carbamazepine, metformin, and caffeine (a compound also arising from lifestyle use), which were detected at over half of the sites monitored. Concentrations of at least one API at 25.7% of the sampling sites were greater than concentrations considered safe for aquatic organisms, or which are of concern in terms of selection for antimicrobial resistance. Therefore, pharmaceutical pollution poses a global threat to environmental and human health, as well as to delivery of the United Nations Sustainable Development Goals.

Eighty percent of wastewater is left untreated or not reused, exacerbating the water quality challenge, especially in vulnerable communities. This Voices asks: how can we improve wastewater management and convert wastewater into a resource?

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.

Agricultural waste represents untapped resources that can be used to produce large value added products with many potential industrial applications. On-farm food waste comprises of harvest and post-harvest waste amounting to 1.2 billion tons per annum and measures up to USD 370 million. Production of food products and other outputs (like biofuel and compost) help in reduction of on-farm food waste and provide livelihood opportunities for the rural households. This reports highlights some innovative approaches across four countries which lead to reduction to food waste. The report cover 6 cases located in Burkina Faso, India, Kenya and Vietnam. The two business models identified in Ouagadougou are – (i) Waka group, that repurpose mango residues in to sweet and bio-vinyl vinegar called MISSIM vinegar, and (ii) SOFAB-SA utilizes oilseeds (such as peanuts, cotton, and soybeans) with blue cheese bran or corn, salt, or any other micro-ingredient to produce feed for livestock. From India, two such case studies are included – (i) Sai Shubhada agro industries is located in Ahmednagar, (Maharashtra, India), and converts bagasse, [a pulpy and fibrous residue of the sugarcane processing] into organic jiggery, and (ii) Arogyasangini Oil Mill, Mill has embarked on the mission to reintroduce oil extracted from the safflower seeds. Nadanya Greens located in Mbale, (Vihiga, Kenya) is exploring the use of farm waste from livestock to produce feeds for fish reared through three fish ponds. Xuan Tien Agricultural Cooperative, located at Yen Chau (Son La province, Vietnam), converts mango which is otherwise wasted post-harvest.

Agricultural waste can be widely adopted to manufacture biogas or biofuel, which is obtained from biomass or agricultural wastes like molasses, bagasse slurries manure etc. Agricultural waste is mostly burned or left decomposing on the fields, where it has potential for polluting the environment and release greenhouse gases. Recovering energy helps to (i) reduce greenhouse emissions by reducing environmental pollution from unwanted biomasses otherwise being burnt in the field; (ii) improve energy efficiency in heating systems from renewable energy sources; (iii) introduce renewable energy by substituting carbon neutral biomass for hydro-carbons (coal, heavy oil and gas); and (iv) Recycle ash residues or slurry as a fertilizer. The present report covers four case studies from Kenya and Burkina Faso related to recovering energy from agrowaste. Biogas International Limited (BIL) is a public private venture in Kenya involved in collection of market waste and recovering biogas, compost, liquid bio fertilizer. The Dunga Beach biogas plant in Kenya turns the invasive water hyacinth (Eichhornia crassipes) on the shores of Lake Victoria to biogas energy, an alternative to charcoal burning for fish vendors at the beach. Keveye Girls is a boarding high school located in Vihiga County. Through consultations and interventions by the Department of Agriculture and Livestock at Vihiga County, Keveye Girls now converts cow dung into biogas, which is then used to power the school’s science laboratories and kitchen as an alternative to LPG gas and wood energy. Similar case studies exist in Burkina Faso. FasoBiogaz, an SME was founded by two Dutch entrepreneurs and supported by the Dutch government and is fully operated by a local team. FasoBiogaz operates the first industrial biogas plant connected to the SONABEL power grid and provides innovative resource recovery solutions producing 550 KW of power.

Plastic usage increases year by year, and the growing trend is projected to continue. However as of 2017, only 9% of the 9 billion tons of plastic ever produced had been recycled leaving large amounts of plastics to contaminate the environment, resulting in important negative health and economic impacts. Curbing this trend is a major challenge that requires urgent and multifaceted action. Based on scientific and gray literature mainly published during the last 10 years, this review summarizes key solutions currently in use globally that have the potential to address at scale the plastic and microplastic contaminations from source to sea. They include technologies to control plastics in solid wastes (i.e. mechanical and chemical plastic recycling or incineration), in-stream (i.e. booms and clean-up boats, trash racks, and sea bins), and microplastics (i.e. stormwater, municipal wastewater and drinking water treatment), as well as general policy measures (i.e. measures to support the informal sector, bans, enforcement of levies, voluntary measures, extended producer responsibility, measures to enhance recycling and guidelines, standards and protocols to guide activities and interventions) to reduce use, reuse, and recycle plastics and microplastics in support of the technological options. The review discusses the effectiveness, capital expenditure, and operation and maintenance costs of the different technologies, the cost of implementation of policy measures, and the suitability of each solution under various conditions. This guidance is expected to help policymakers and practitioners address, in a sustainable and cost-efficient way, the plastic and microplastic management problem using technologies and policy instruments suitable in their local context.

This study reveals rainfall variability and trends in the African continent using TAMSAT data from 1983 to 2020. In the study, a Mann–Kendall (MK) test and Sen’s slope estimator were used to analyze rainfall trends and their magnitude, respectively, under monthly, seasonal, and annual timeframes as an indication of climate change using different natural and geographical contexts (i.e., sub-regions, climate zones, major river basins, and countries). The study finds that the highest annual rainfall trends were recorded in Rwanda (11.97 mm/year), the Gulf of Guinea (river basin 8.71 mm/year), the tropical rainforest climate zone (8.21 mm/year), and the Central African region (6.84 mm/year), while Mozambique (-0.437 mm/year), the subtropical northern desert (0.80 mm/year), the west coast river basin of South Africa (-0.360 mm/year), and the Northern Africa region (1.07 mm/year) show the lowest annual rainfall trends. There is a statistically significant increase in the rainfall in the countries of Africa’s northern and central regions, while there is no statistically significant change in the countries of the southern and eastern regions. In terms of climate zones, in the tropical northern desert climates, tropical northern peninsulas, and tropical grasslands, there is a significant increase in rainfall over the entire timeframe of the month, season, and year. This implies that increased rainfall will have a positive effect on the food security of the countries in those climatic zones. Since a large percentage of Africa’s agriculture is based only on rainfall (i.e., rain-fed agriculture), increasing trends in rainfall can assist climate resilience and adaptation, while declining rainfall trends can badly affect it. This information can be crucial for decision-makers concerned with effective crop planning and water resource management. The rainfall variability and trend analysis of this study provide important information to decision-makers that need to effectively mitigate drought and flood risk.

Access to sufficient and clean freshwater is essential for all life. Water is also essential for food system functioning: as a key input into food production, but also in processing and preparation, and as a food itself. Water scarcity and pollution are growing, affecting poorer populations, particularly food producers. Malnutrition levels are also on the rise, and this is closely linked to water scarcity. The achievement of Sustainable Development Goal (SDG) 2 and SDG 6 are co-dependent. Solutions to jointly improve food systems and water security outcomes that the United Nations Food Security Summit (UNFSS) should consider include: 1) strengthening efforts to retain water-based ecosystems and their functions; 2) improving agricultural water management for better diets for all; 3) reducing water and food losses beyond the farmgate; 4) coordinating water with nutrition and health interventions; 5) increasing the environmental sustainability of food systems; 6) explicitly addressing social inequities in water-nutrition linkages; and 7) improving data quality and monitoring for water-food system linkages, drawing on innovations in information and communications technology (ICT).

Existing climate projections and impact assessments in Nepal only consider a limited number of generic climate indices such as means. Few studies have explored climate extremes and their sectoral implications. This study evaluates future scenarios of extreme climate indices from the list of the Expert Team on Sector-specific Climate Indices (ET-SCI) and their sectoral implications in the Karnali Basin in western Nepal. First, future projections of 26 climate indices relevant to six climate-sensitive sectors in Karnali are made for the near (2021–2045), mid (2046–2070), and far (2071–2095) future for low-and high-emission scenarios (RCP4.5 and RCP8.5, respectively) using bias-corrected ensembles of 19 regional climate models from the COordinated Regional Downscaling EXperiment for South Asia (CORDEX-SA). Second, a qualitative analysis based on expert interviews and a literature review on the impact of the projected climate extremes on the climate-sensitive sectors is undertaken. Both the temperature and precipitation patterns are projected to deviate significantly from the historical reference already from the near future with increased occurrences of extreme events. Winter in the highlands is expected to become warmer and dryer. The hot and wet tropical summer in the lowlands will become hotter with longer warm spells and fewer cold days. Low-intensity precipitation events will decline, but the magnitude and frequency of extreme precipitation events will increase. The compounding effects of the increase in extreme temperature and precipitation events will have largely negative implications for the six climate-sensitive sectors considered here.

Wastewater-fed aquaculture has a long history, especially in Asia. This report examines three empirical cases of integrated wastewater treatment and aquaculture production. From an aquaculture entrepreneur’s perspective, the combination of fish farming and wastewater treatment in common waste stabilization ponds allows significant savings on capital (pond infrastructure) and running costs (wastewater supporting fish feed). On the other hand, the treatment plant owner will have the benefit of a partner taking over plant maintenance. Given the importance of food safety and related perceptions, the report is focusing on innovative business models where the marketed fish is not in direct contact with the treated wastewater, but only the brood stock or fish feed. The financial analysis of the presented systems shows profitable options for the fish farmer, operational and in part capital cost recovery for the treatment plant, and as the treatment plant operators can stop charging households a sanitation fee, eventually a triple-win situation for both partners and the served community.

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.

Humanity is in a planetary emergency. Agriculture and food systems are contributing to an interconnected global environmental crisis, with increasing risks, social instability, and conflict. This chapter examines the challenges, drivers, and consequences of unsustainable agriculture and food systems, recognizing these are diverse and multi-scale. It presents a vision for sustainable, nutritious, and equitable food systems. Currently, food systems are a significant driver of climate change, nature loss, and pollution, as well as poor health and poverty, with inequitable access to resources and benefits from food systems. Fundamentally, the systems change needed is to transform terrestrial and aquatic food systems so that they become part of the solution for sustainability, not part of the problem. A safe future for humanity requires radical transformations ranging from agricultural production systems through dietary patterns and waste disposal. The focus is on the broad categories of innovation and sustainable technologies considered to have critical potential in pathways that enable transition to a more resilient and equitable system. Governance is a key enabling condition and needs to be based on food as a human right, not simply as a commodity. Multilevel governance underpins the development and implementation of territorial food systems strategies, which can provide effective integration of multiple solutions. Humanity is at an existential turning point and has a narrow window to act now to reduce risk and avoid catastrophe. The rules governing our food systems are human made – and it is within the gift of humanity to change them.

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.

Expansion of various types of water infrastructure is critical to water security in Africa. To date, analysis of adverse disease impacts has focused mainly on large dams. The aim of this study was to examine the effect of both small and large dams on malaria in four river basins in sub-Saharan Africa (i.e., the Limpopo, Omo-Turkana, Volta and Zambezi river basins). The European Commission’s Joint Research Center (JRC) Yearly Water Classification History v1.0 data set was used to identify water bodies in each of the basins. Annual malaria incidence data were obtained from the Malaria Atlas Project (MAP) database for the years 2000, 2005, 2010 and 2015. A total of 4907 small dams and 258 large dams in the four basins, with 14.7million people living close (lt; 5 km) to their reservoirs in 2015, were analysed. The annual number of malaria cases attributable to dams of either size across the four basins was 0.9–1.7 million depending on the year, of which between 77 and 85% was due to small dams. The majority of these cases occur in areas of stable transmission. Malaria incidence per kilometre of reservoir shoreline varied between years but for small dams was typically 2–7 times greater than that for large dams in the same basin. Between 2000 and 2015, the annual malaria incidence showed a broadly declining trend for both large and small dam reservoirs in areas of stable transmission in all four basins. In conclusion, the malaria impact of dams is far greater than previously recognized. Small and large dams represent hotspots of malaria transmission and, as such, should be a critical focus of future disease control efforts.

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.

Landslides are among the most dangerous natural hazards, particularly in developing countries, where ground observations for operative early warning systems are lacking. In these areas, remote sensing can represent an important detection and monitoring process to predict landslide occurrence in space and time, particularly satellite rainfall products that have improved in terms of accuracy and resolution in recent times. Surprisingly, only a few studies have investigated the capability and effectiveness of these products in landslide prediction in reducing the impact of this hazard on the population. We have performed a comparative study of ground and satellite-based rainfall products for landslide prediction in India by using empirical rainfall thresholds derived from the analysis of historical landslide events. Specifically, we have tested Global Precipitation Measurement (GPM) and SM2RAIN-ASCAT satellite rainfall products, and their merging, at daily and hourly temporal resolution, and Indian Meteorological Department (IMD) daily rain gauge observations. A catalogue of 197 rainfall-induced landslides that occurred throughout India in the 13-year period between April 2007 and October 2019 has been used. Results indicate that satellite rainfall products outperform ground observations thanks to their better spatial (0.1 vs. 0.25 ) and temporal (hourly vs. daily) resolutions. The better performance is obtained through the merged GPM and SM2RAIN-ASCAT products, even though improvements in reproducing the daily rainfall (e.g. overestimation of the number of rainy days) are likely needed. These findings open a new avenue for using such satellite products in landslide early warning systems, particularly in poorly gauged areas.

Access to sufficient and clean freshwater is essential for all life. Water is also essential for food system functioning: as a key input into food production, but also in processing and preparation, and as a food itself. Water scarcity and pollution are growing, affecting poorer populations, particularly food producers. Malnutrition levels are also on the rise, and this is closely linked to water scarcity. Achievement of Sustainable Development Goal 2 (SDG 2) and Sustainable Development Goal 6 (SDG 6) are co-dependent. Solutions to jointly improve food systems and water security outcomes that the United Nations Food Security Summit (UNFSS) should consider include: 1) Strengthening efforts to retain water-based ecosystems and their functions; 2) Improving agricultural water management for better diets for all; 3) Reducing water and food losses beyond the farmgate; 4) Coordinating water with nutrition and health interventions; 5) Increasing the environmental sustainability of food systems; 6) Explicitly addressing social inequities in water-nutrition linkages; and 7) Improving data quality and monitoring for water-food system linkages, drawing on innovations in information and communications technology (ICT).

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.

Until recently, households in the most chronic kidney disease-affected rural areas of Sri Lanka used untreated groundwater for drinking and cooking, but, by 2018, that share was only 35%. About 50% of households consume water treated by reverse osmosis; others rely on piped water, water delivery by tanker and rainwater harvesting. Based on a new and representative survey of 1500 households, households’ propensities to treat drinking water and adopt improved water sources are shown to be associated with their perceptions of water safety and trust in the institutions that provide alternatives to untreated well water.

This paper outlines a new and integrated water storage agenda for resilient development in a world increasingly characterised by water stress and climate uncertainty and variability.; Storing water has long been a cornerstone of socio-economic development, particularly for societies exposed to large climatic variability. Nature has always supplied the bulk of water storage on earth, but built storage has increased significantly, particularly over the twentieth century. Today, numerous countries suffer from water storage gaps and increasingly variable precipitation, threatening sustainable development and even societal stability. There is a growing need to develop more storage types and manage existing storage better. At the same time, the policy, engineering, and scientific communities may not fully recognise the extent of these storage gaps and how best to manage them. There are large and uncertain costs and benefits of different types of storage, and developing storage can be risky and controversial. Although there is consensus that built and natural storage are fundamentally complementary, there is still no pragmatic agenda to guide future integrated water storage development.; This paper argues that water storage should be recognised as a service rather than only a facility. More than volumes of water stored behind a dam or in a watershed, what ultimately matters is the ability to provide different services at a particular time and place with a given level of assurance. Integrated storage systems should be developed and managed to deliver a targeted service standard. This will reduce the costs of new storage development and make the benefits more sustainable.; As this paper demonstrates, there are numerous data gaps pertaining to water storage, as well as a need for greater clarity on some key concepts. This paper does not introduce new data or research but rather provides a review of some of the current knowledge and issues around water storage, and outlines a new, integrated and constructive water storage agenda for the decades to come.

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.

The countries around the world are dealing with air quality issues for decades due to their mode of production and energy usages. The outbreak of COVID-19 as a pandemic and consequent global economic shutdown, for the first time, provided a base for the real-time experiment of the effect of reduced emissions across the globe in abetting the air pollution issue. The present study dealt with the changes in Aerosol Optical Depth (AOD), a marker of air pollution, because of global economic shutdown due to the coronavirus pandemic. The study considered the countries in south and south-east Asia (SSEA), Europe and the USA for their extended period of lockdown due to coronavirus pandemic. Daily Aerosol Optical Depth (AOD) from Moderate-resolution imaging spectroradiometer (MODIS) and tropospheric column density of NO2 and SO2 from Ozone monitoring instrument (OMI) sensors, including meteorological data such as wind speed (WS) and relative humidity (RH) were analyzed during the pre-lockdown (2017–2019) and lockdown periods (2020). The average AOD, NO2 and SO2 during the lockdown period were statistically compared with their pre-lockdown average using Wilcoxon-signed-paired-rank test. The accuracy of the MODIS-derived AOD, including the changing pattern of AOD due to lockdown was estimated using AERONET data. The weekly anomaly of AOD, NO2 and SO2 was used for analyzing the space-time variation of aerosol load as restrictions were imposed by the concerned countries at the different points of time. Additionally, a random forest-based regression (RF) model was used to examine the effects of meteorological and emission parameters on the spatial variation of AOD. A significant reduction of AOD (- 20%) was obtained for majority of the areas in SSEA, Europe and USA during the lockdown period. Yet, the clusters of increased AOD (30–60%) was obtained in the south-east part of SSEA, the western part of Europe and US regions. NO2 reductions were measured up to 20–40%, while SO2 emission increased up to 30% for a majority of areas in these regions. A notable space-time variation was observed in weekly anomaly. We found the evidence of the formation of new particles for causing high AOD under high RH and low WS, aided by the downward vertical wind flow. The RF model showed a distinguishable relative importance of emission and meteorological factors among these regions to account for the spatial variability of AOD. Our findings suggest that the continued lockdown might provide a temporary solution to air pollution; however, to combat persistent air quality issues, it needs switching over to the cleaner mode of production and energy. The findings of this study, thus, advocated for alternative energy policy at the global scale.

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.

Little is known about the occurrence of emerging pollutants (EPs) in waters in the Middle East and North Africa (MENA) region despite the extensive use of low-quality water there. Available data dealing with the sources, occurrence and removal of EPs within the MENA region in different categories of water is collected, presented and analyzed in this literature review. According to the collected database, the occurrence and removal efficiency of EPs in the water matrix in the MENA region is available, respectively, for 13 and six countries of the 18 in total; no available data is registered for the rest. Altogether, 290 EPs have been observed in different water matrices across the MENA countries, stemming mainly from industrial effluents, agricultural practices, and discharge or reuse of treated wastewater (TWW). Pharmaceutical compounds figure among the most frequently reported compounds in wastewater, TWW, surface water, and drinking water. Nevertheless, pesticides are the most frequently detected pollutants in groundwater. Worryingly, 57 cases of EPs have been reported in different fresh and drinking waters, exceeding World Health Organization (WHO) and European Commission (EC) thresholds. Overall, pharmaceuticals, organic compounds, and pesticides are the most concerning EP groups. The review revealed the ineffectiveness of treatment processes used in the region to remove EPs. Negative removals of some EPs such as carbamazepine, erythromycin, and sulfamethoxazole were recorded, suggesting their possible accumulation or release during treatment. This underlines the need to set in place and strengthen control measures, treatment procedures, standards, and policies for such pollutants in the region.

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.

This report examines social equality aspects related to resource recovery through solid waste composting and wastewater irrigation. The report shows that women are represented in greatest numbers at the base of the recycling chain, most often as informal waste pickers and as sorters of recyclables with limited access to resources and upward mobility. Despite a wide gender gap in the solid waste and sanitation sectors, women play a key role in both municipal waste reduction and food safety where irrigation water is unsafe. Analyzing the gender dimension is important for understanding household responses to recycling programs, differences between the formal and informal sectors as well as along the waste-to-resource value chain from collection to treatment and reuse. The report stresses the important role of women in household waste management, including waste segregation, and the power of women-dominated waste picker associations, where the informal sector plays an essential role alongside the formal sector.

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.

Commercial farming of banana for export has rapidly expanded across northern uplands of Laos since 2008 with the establishment of new plantations by foreign companies. Heavy reliance on agrochemical usage warrants examination of possible environmental and human health risks. This study presents a preliminary assessment of the environmental risks from pesticide usage associated with bananas and other major crops in Oudomxay province. Surface water, groundwater, soil and sediment samples collected from the study area were analyzed for pesticide residues in the laboratory during the wet and dry seasons. Results of the analysis revealed that samples from banana farms had higher concentrations of residues from currently used (CU) pesticides compared with samples from adjacent farms producing maize, rubber, upland rice and gourd. Residues from highly persistent organochlorine (OC) pesticides, such as dichlorodiphenyltrichloroethane, heptachlor, dieldrin and lindane, which are no longer used in Laos, were also detected. Laboratory results were compared against a low-cost pesticide residue detection method and a simple pesticide risk assessment tool. However, neither approach was comparable to laboratory analysis. The potential environmental risk from pesticides and pesticide breakdown products was found to be substantial. For example, concentrations of some CU compounds exceeded the limits set by the World Health Organization. The report highlights several mitigation measures to reduce the environmental risks from hazardous pesticides: (i) increase efforts to eliminate the import and use of hazardous and persistent pesticides; (ii) promote targeted education programs to implement best practices, including the selection and use of pesticides as per international standards, and Integrated Pest Management techniques; (iii) identify and protect drinking water sources with a high risk of contamination; and (iv) maintain vegetated buffers and sediment traps to detain farm runoff, which will allow CU pesticides to degrade to safe levels before entering watercourses.

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.

This chapter documents and assesses available best practices and technologies that can be employed to mitigate the release of microplastics from textiles and tyres into the environment. The chapter follows a life-cycle approach, discussing options implementable at the design and manufacturing, use and end-of-life phases, as well as options for the end-of-pipe capture of microplastics.

While drinking water is known to create significant health risk in arsenic hazard areas, the role of exposure to arsenic through food intake is less well understood, including the impact of food trade. Using the best available datasets on crop production, irrigation, groundwater arsenic hazard, and international crop trade flows, we estimate that globally 17.2% of irrigated harvested area (or 45.2 million hectares) of 42 main crops are grown in arsenic hazard areas, contributing 19.7% of total irrigated crop production, or 418 million metric tons (MMT) per year of these crops by mass. Two-thirds of this area is dedicated to the major staple crops of rice, wheat, and maize (RWM) and produces 158 MMT per year of RWM, which is 8.0% of the total RWM production and 18% of irrigated production. More than 25% of RWM consumed in the South Asian countries of India, Pakistan, and Bangladesh, where both arsenic hazard and degree of groundwater irrigation are high, originate from arsenic hazard areas. Exposure to arsenic risk from crops also comes from international trade, with 10.6% of rice, 2.4% of wheat, and 4.1% of maize trade flows coming from production in hazard areas. Trade plays a critical role in redistributing risk, with the greatest exposure risk borne by countries with a high dependence on food imports, particularly in the Middle East and small island nations for which all arsenic risk in crops is imported. Intensifying climate variability and population growth may increase reliance on groundwater irrigation, including in arsenic hazard areas. Results show that RWM harvested area could increase by 54.1 million hectares (179% increase over current risk area), predominantly in South and Southeast Asia. This calls for the need to better understand the relative risk of arsenic exposure through food intake, considering the influence of growing trade and increased groundwater reliance for crop production.

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.

Globally, 50% of the population relies on on-site sanitation systems (OSS) such as septic tanks and pit latrines and is, hence, in need of Fecal Sludge Management (FSM) solutions. India is a classic example, given that its government built more than 100 million toilets with the majority relying on OSS. With 400 fecal sludge treatment plants (FSTPs) in various stages of planning, procurement and construction, this report comes at an opportune time to present findings on FSM business models already implemented across India. Interviews were conducted with a total of 105 Emptying and Transport (Eamp;T) operators in 72 towns and cities across 16 states in India, 22 representatives from municipalities that own emptying vehicles, 18 FSTP operators and more than 30 institutions. In addition, procurement tenders for Eamp;T and FSTPs in 13 states were analyzed. In total, 18 business models were identified, several with energy or nutrient recovery components. The analysis of Eamp;T operators revealed clear differences that steer a business towards success or failure. The majority of operators still dispose fecal sludge in an unsafe manner, due to the lack of official disposal or treatment sites. In comparison to sewer networks, the capital and operating costs (per capita) of FSTPs were significantly lower. The report provides evidence-based discussions on policies and recommendations for scaling and sustaining FSM.

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.

Unmanned Aerial Vehicles (UAVs) are an alternative to costly and time-consuming traditional methods to improve agricultural water management and crop productivity through the acquisition, processing, and analyses of high-resolution spatial and temporal crop data at field scale. UAVs mounted with multispectral and thermal cameras facilitate the monitoring of crops throughout the crop growing cycle, allowing for timely detection and intervention in case of any anomalies. The use of UAVs in smallholder agriculture is poised to ensure food security at household level and improve agricultural water management in developing countries. This review synthesises the use of UAVs in smallholder agriculture in the smallholder agriculture sector in developing countries. The review highlights the role of UAV derived normalised difference vegetation index (NDVI) in assessing crop health, evapotranspiration, water stress and disaster risk reduction. The focus is to provide more accurate statistics on irrigated areas, crop water requirements and to improve water productivity and crop yield. UAVs facilitate access to agro-meteorological information at field scale and in near real-time, important information for irrigation scheduling and other on-field decision-making. The technology improves smallholder agriculture by facilitating access to information on crop biophysical parameters in near real-time for improved preparedness and operational decision-making. Coupled with accurate meteorological data, the technology allows for precise estimations of crop water requirements and crop evapotranspiration at high spatial resolution. Timely access to crop health information helps inform operational decisions at the farm level, and thus, enhancing rural livelihoods and wellbeing.

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.

Applicability of satellite rainfall products must be explored since rain gauge networks have limitations to provide adequate spatial coverage. In this study, Climate Hazards InfraRed Precipitation (CHIRP) satellite-only product was evaluated for rainfall-runoff modeling whereas the simulated runoff served as input to simulate the water levels of Lake Ziway from 1986 to 2014. CHIRP dataset was bias-corrected using power transformation and used as input to Hydrologiska Byrns Vattenbalansavdelning (HBV) model to simulate streamflow of Meki and Katar catchments. Results showed that gauged catchments of Meki and Katar contributed 524 and 855 mm to the annual lake inflow, respectively. The estimated runoff from ungauged catchments is 182 mm that amounts to approximately 8.5% of the total lake inflow over the period 1986–2000. The results of lake level simulation show good agreement from 1986 to 2000, but deteriorating agreement after 2000, which is mainly attributed to errors in water balance terms and human-induced impacts. For the period 1986–2000, the water balance closure error for the lake was 67.5 mm per year, which accounts for 2.9% of the total lake inflow from rainfall and river inflow. This study shows bias correction increases the applicability of CHIRP satellite product for lake water balance studies.

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.

We compare the effect of the wetting front detector on yield and water productivity with farmersapos; practices (FP) and irrigation requirements based on crop water requirement calculation (IRCWR). A field experiment was conducted to assess the effect of the wetting front detector, FP and IRCWR combined with six fertilizer rates. We also interviewed 50 farmers to understand their perception about the use and associated concerns with the wetting front detector. Analysis of variance and partial budget economic analysis were performed. The results show that the wetting front detector saved 16% of irrigation water compared to FP, which in turn led to 16% labour saving to irrigate pepper as compared to FP. Yield and water productivity of pepper were not significantly affected by the irrigation regimes. Regardless of irrigation regimes, yield of pepper was significantly influenced by fertilizer treatment in both years. Although the highest fresh fruit yield of pepper (8.6 t ha-1 ) was recorded from Fortifer granules, the highest marginal rate of return was obtained from application of inorganic fertilizer including 173 N, 36 P,18 K ha ¹. The majority of farmers perceived the wetting front detector as low risk and compatible to use. The result also suggests that farmers are interested in buying and adopting the tool for future use.

This article reviews the negative impact of anthropogenic changes on groundwater. The main changes in physical and geographical conditions that occur under the impact of anthropogenic pressures and that have the most significant influence on the state of groundwater, as well as a negative impaction the conditions of the formation of groundwater are: changes in the landscape caused by agricultural works, mining, construction of settlements, etc.; changes in the hydrographic network caused the construction of hydroelectric power facilities; changes in the composition of the atmospheric air; changes in the groundwater level regime, climatic conditions. The most significant factor of change in groundwater formation conditions is the progressive anthropogenic pollution of groundwater. It negatively influences the number of resources and their quality.

Urbanisation will be one of the 21st centuryapos;s most transformative trends. By 2050, it will increase from 55% to 68%, more than doubling the urban population in South Asia and Sub-Saharan Africa. Urbanisation has multifarious (positive as well as negative) impacts on the wellbeing of humans and the environment. The 17 UN Sustainable Development Goals (SDGs) form the blueprint to achieve a sustainable future for all. Clean Water and Sanitation is a specific goal (SDG 6) within the suite of 17 interconnected goals. Here we provide an overview of some of the challenges that urbanisation poses in relation to SDG 6, especially in developing economies. Worldwide, several cities are on the verge of water crisis. Water distribution to informal settlements or slums in megacities (e.g. N50% population in the megacities of India) is essentially non-existent and limits access to adequate safe water supply. Besides due to poor sewer connectivity in the emerging economies, there is a heavy reliance on septic tanks, and other on-site sanitation (OSS) system and by 2030, 4.9 billion people are expected to rely on OSS. About 62–93% of the urban population in Vietnam, Sri Lanka, the Philippines and Indonesia rely on septic tanks, where septage treatment is rare. Globally, over 80% of wastewater is released to the environment without adequate treatment. About 11% of all irrigated croplands is irrigated with such untreated or poorly treated wastewater. In addition to acute and chronic health effects, this also results in significant pollution of often-limited surface and groundwater resources in Sub-Saharan Africa and Asia. Direct and indirect water reuse plays a key role in global water and food security. Here we offer several suggestions to mitigate water and food insecurity in emerging economies.

Endosulfan, a mixture of a- and -isomers, is used by farmers in the wet and dry season for khat and onion production. Khat leaf samples were collected in farmer fields at intervals of 1 h; 1, 5, 9 and 14 d after application. The dissipation rate of a- and -isomers and residue level in khat were compared with residue levels in onion. The extraction was done by using Quick Easy Cheap Effective Rugged and Safe (QuEChERS) method and analyzed by Gas Chromatography – Electron Capture Detector (GC-ECD). Greater residue a- and -isomer endosulfan levels were found in khat compared to onion as khat leaves are sprayed repeatedly in two week. Residue levels of khat exceeded the tolerable EU limit of 0.05 mg.kg-1 for leafy vegetables and herbs. For both raw and processed onion sample a- and endosulfan residues level were below the tolerable of limit EU regulation for bulb vegetables (i.e. 0. 1 mg.kg-1). The mean half-life for the a-isomer of endosulfan was 3.4 d in the wet season and 3.6 d in the dry season whilst that for the -isomer was 5.0 d and 5.4 d respectively. Both isomers dissipated fastest in the wet season under conditions of high humidity and precipitation. The -isomer persisted longer and had a lower dissipation rate from plants surface compared to the a-isomer.

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.

Agriculture is critical to the economies of developing countries. It is the basic source of food supply and a major contributor to economic development. But there is a cost. Today, agricultural water pollution undermines economic growth and threatens the environmental and physical health of millions of people around the world. The annual social and economic costs of agricultural water pollution could reach trillions of dollars. Yet the issue receives scant attention in global research and debate.

This chapter outlines legal, institutional and political means to support climate change adaptation and mitigation, to enhance resilience, and to reduce vulnerability through more inclusive water management, especially at the country level.

This chapter focuses on the human health impacts associated with changes in water quality and quantity due to climate change. Trends in morbidity and mortality are examined in the context of health risks associated with climate change, and response options related to water supply and sanitation are presented.

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.

This paper examines whether there are systematic differences in the historical behaviors of households that are affected and unaffected by chronic kidney disease (CKD) in Sri Lanka pertaining to their water source choices, water treatment practices, and agrochemical use. This analysis is motivated by the Sri Lankan government’s largest policy response to this epidemic – to encourage communities to switch from untreated well water to publicly provided alternatives. We use recall methods to elicit information on the drinking water source and treatment choices of households over an 18-year period from 2000– 2017. Our analysis is based on a survey of 1497 rural ground-water dependent households in the most CKD-affected areas of the 10 districts of Sri Lanka with the highest prevalence of CKD. Our main findings are that (a) households that have ever used a pump to extract (typically deep) drinking water from a household well are more likely to be affected by CKD; (b) we fail to find a relationship between disease status and households’ use of buckets to extract (typically shallow) groundwater from their wells; and (c) those who have ever treated their shallow well water by boiling it are less likely to be affected by CKD. We also find that a greater share of CKD affected households historically used agrochemicals, used wells that were geographically removed from surface water sources, and displayed lower proxies of wealth. The implications of these findings are fourfold. First, since the systematic differences in the historical patterns of water sources and treatments used by CKD affected and non-affected households are modest, the sources of water and the treatment practices themselves may not be the sole risk factors in developing CKD. Second, although we find a negative association between boiling water and the probability of CKD, it is not obvious that a public policy campaign to promote boiling water is an appropriate response. Third, the hydrochemistry of deep and shallow well water needs to be better understood in order to shed light on the positive relationship between deep well water and disease status, and on why boiling shallow but not deep well water is associated with a lower probability of CKD. Fourth, there is a need for a deeper understanding of other risk factors and of the efficacy of preventative programs that provide alternative sources of household drinking water.

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.

Credit constraint is considered by many as one of the key barriers to adoption of modern agricultural technologies, such as chemical fertilizer, improved seeds, and irrigation technologies, among smallholders. Past research and much policy discourse associates agricultural credit constraints with supply-side factors, such as limited access to credit sources or high costs of borrowing. However, demand-side factors, such as risk-aversion and financial illiteracy among borrowers, as well as high transaction costs, can also play important roles in credit-rationing for smallholders. Using primary survey data from Ethiopia and Tanzania, this study examines the nature of credit constraints facing smallholders and the factors that affect credit constraints. In addition, we assess whether credit constraints are gender-differentiated. Results show that demand-side credit constraints are at least as important as supply-side factors in both countries. Women are more likely to be credit constrained (from both the supply and demand sides) than men. Based on these findings, we suggest that policies should focus on addressing both supply- and demand-side credit constraints, including through targeted interventions to reduce risk, such as crop insurance and gender-sensitive policies to improve women’s access to credit.

This working paper was produced under the European Union Horizon 2020 funded AGRUMIG project and traces the impact of Covid-19 on migration trends in seven project countries – China, Ethiopia, Kyrgyzstan, Moldova, Morocco, Nepal and Thailand. The context of global migration has changed dramatically due to the coronavirus pandemic. Both within and between countries there has been a substantial curtailment of movement. As a result of multiple lockdowns, economic activity has severely declined and labor markets have ground to a halt, with mass unemployment in industrialized economies looming on the horizon. For both migrant hosting and origin countries – some are substantially both – this poses a set of complex development challenges. Partners of the AGRUMIG project undertook a rapid review of impacts across project countries, exploring the impacts on rural households but also identifying the persistent desire to migrate in spite of restrictions.

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.

With the objective to provide a basis for regional climate models (RCMs) selection and ensemble generation for climate impact assessments, we perform the first ever analysis of climate projections for Western Nepal from 19 RCMs in the Coordinated Regional Downscaling Experiment for South Asia (CORDEX-SA). Using the climate futures (CF) framework, projected changes in annual total precipitation and average minimum/maximum temperature from the RCMs are classified into 18 CF matrices for two representative concentration pathways (RCPs: 4.5/8.5), three future time frames (2021–2045/2046–2070/2071–2095), three geographic regions (mountains/hills/plains) and three representative CF (low-risk/consensus/ high-risk). Ten plausible CF scenario ensembles were identified to assess future water availability in Karnali basin, the headwaters of the Ganges. Comparison of projections for the three regions with literature shows that spatial disaggregation possible using RCMs is important, as local values are often higher with higher variability than values for South Asia. Characterization of future climate using raw and bias-corrected data shows that RCM projections vary most between mountain and Tarai plains with increasing divergence for higher future and RCPs. Warmer temperatures, prolonged monsoon and sporadic rain events even in drier months are likely across all regions. Highest fluctuations in precipitation are projected for the hills and plains while highest changes in temperature are projected for the mountains. Trends in change in annual average discharge for the scenarios vary across the basin with both precipitation and temperature change influencing the hydrological cycle. CF matrices provide an accessible and simplified basis to systematically generate application-specific plausible climate scenario ensembles from all available RCMs for a rigorous impact assessment.

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.

The term “environmental flows” refers to a combination of features, including quantity, quality, and timing of water flows required to sustainably maintain a river’s health, balancing both ecological and societal needs. Incorporating basic human livelihood and sociocultural aspects in environmental flow assessments alongside ecological concerns provides a more holistic perspective on water flow management. Here, we provide an assessment that complements an ecosystem functioning lens by focusing solely on quantifying the flows associated with livelihood activities and spiritual water requirements of local riparian communities in the Karnali basin in Western Nepal. This assessment is based on the first social survey related to environmental flows conducted in the Karnali basin. We collected data using mixed methods, including social surveys, key informant interviews, and focus group discussions, across six locations in the Karnali basin that provide us with a rich and dynamic perspective on the relationship between rivers and their surrounding communities, and the challenges faced by those communities. Among the subsistence and spiritual requirements of local communities are uses for activities that include drinking, small-scale irrigation, domestic needs, fishing, and ceremonial usage. All communities we visited most strongly associated the following activities with water flow variation: small-scale irrigation, fishing, ceremonial usage, domestic needs, and tourism. The water flows required for these key activities were quantified, and results from the six sites are presented in the form of a qualitative scale of minimum water levels (ranging across poor, acceptable, and ideal) required to meet vital local needs. The minimum acceptable water flow requirement to satisfy social criteria is just gt; 20% of the mean annual runoff at the visited locations. These requirements are particularly vital to consider, given ongoing efforts to tap the vast hydropower potential in Nepal through construction of major storage projects. Such projects would change the flow regime of affected rivers and potentially raise concerns that existing demands might be compromised.

Over the last decade, the International Water Management Institute (IWMI) has explored the use of fecal sludge (FS) in combination with other organic waste sources to optimize FS treatment and composting for the production of a safe organic fertilizer, which can – depending on demand – be enriched with crop nutrients or pelletized for volume reduction, delayed decomposition or easier application. Based on IWMI’s experience, this training manual has been compiled for plant managers and trainers to help ensure that staff involved in FS treatment and production, and application of an FS-based co-compost adopt best practices in all processes involved. The manual can be adapted to local needs as required. It also includes information on compost registration and certification, as well as guidelines for co-compost application in the field.

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.

The last 60 years has seen unprecedented groundwater extraction and overdraft as well as development of new technologies for water treatment that together drive the advance in intentional groundwater replenishment known as managed aquifer recharge (MAR). This paper is the first known attempt to quantify the volume of MAR at global scale, and to illustrate the advancement of all the major types of MAR and relate these to research and regulatory advancements. Faced with changing climate and rising intensity of climate extremes, MAR is an increasingly important water management strategy, alongside demand management, to maintain, enhance and secure stressed groundwater systems and to protect and improve water quality. During this time, scientific research—on hydraulic design of facilities, tracer studies, managing clogging, recovery efficiency and water quality changes in aquifers—has underpinned practical improvements in MAR and has had broader benefits in hydrogeology. Recharge wells have greatly accelerated recharge, particularly in urban areas and for mine water management. In recent years, research into governance, operating practices, reliability, economics, risk assessment and public acceptance of MAR has been undertaken. Since the 1960s, implementation of MAR has accelerated at a rate of 5%/year, but is not keeping pace with increasing groundwater extraction. Currently, MAR has reached an estimated 10 km3/year, ~2.4% of groundwater extraction in countries reporting MAR (or ~1.0% of global groundwater extraction). MAR is likely to exceed 10% of global extraction, based on experience where MAR is more advanced, to sustain quantity, reliability and quality of water supplies.

Background: The impact of large dams on malaria has received widespread attention. However, understanding how dam topography and transmission endemicity influence malaria incidences is limited. ; Methods: Data from the European Commission’s Joint Research Center and Shuttle Radar Topography Mission were used to determine reservoir perimeters and shoreline slope of African dams. Georeferenced data from the Malaria Atlas Project (MAP) were used to estimate malaria incidence rates in communities near reservoir shorelines. Population data from the WorldPop database were used to estimate the population at risk of malaria around dams in stable and unstable areas. ; Results: The data showed that people living near (lt; 5 km) large dams in sub-Saharan Africa grew from 14.4 million in 2000 to 18.7 million in 2015. Overall, across sub-Saharan Africa between 0.7 and 1.6 million malaria cases per year are attributable to large dams. Whilst annual malaria incidence declined markedly in both stable and unstable areas between 2000 and 2015, the malaria impact of dams appeared to increase in unstable areas, but decreased in stable areas. Shoreline slope was found to be the most important malaria risk factor in dam-affected geographies, explaining 41–82% (P lt; 0.001) of the variation in malaria incidence around reservoirs. ; Conclusion: Gentler, more gradual shoreline slopes were associated with much greater malaria risk. Dam-related environmental variables such as dam topography and shoreline slopes are an important factor that should be considered in efforts to predict and control malaria around dams.

A water and soil quality baseline study was carried out across the ~ 4500 km2 Vientiane Plain in Lao PDR. Eight water quality and nine soil parameters were analysed using field kits at 95 sites in March 2015. Elevated electrical conductivity and chloride were apparent at two sites due to geogenic leaching from the marine rock-salt present in some areas. Groundwater was acidic in most locations. Nitrate and faecal contamination were also observed from nitrogenous fertilizers (diffuse) and from leaky sewage pits (localised) respectively. Soil quality is neither nutrient deficient nor does it pose a threat to plant growth. Where groundwater is used for drinking, removal of bacterial contamination by simple filtration or boiling is sufficient. In the absence of a functional monitoring network in the Vientiane Plain, periodic surveys of this kind should be performed. The results should be made widely available to the relevant government departments and other stakeholders for better management of the land and water resources.

In low- and middle-income countries, the management of fecal sludge from on-site sanitation systems has received little attention over many decades, resulting in insufficient or missing regulations to guide investments and management options. To address this gap, this report examines existing and emerging guidelines and regulations for fecal sludge management (FSM) along the sanitation service chain (user interface, containment, emptying, transport, treatment, valorization, reuse or disposal). It also draws empirical examples from guidelines across the globe to support policy-makers, planners, and sanitation and health officers, as well as consultants in low- and middle-income countries in the development and design of local and national FSM guidelines and regulations.

Mainstreaming gender in water governance through “how to do gender” toolkits has long been a development focus. It has been widely argued that such toolkits simplify the complex, nuanced realities of inequalities by gender in relation to water and fail to pay attention to the fact that the proposed users of such gender-water toolkits, i.e. mostly male water sector professionals, lack the skills, motivation and/or incentives to apply these toolkits in their everyday work. We adopt a feminist political ecology lens to analyse some of the barriers to reduce social inequalities in the management of global commons such as international rivers. Our findings highlight the leap of faith made in the belief that gender toolkits, as they exist, will filter through layers of a predominantly masculine institutional culture to enable change in ground realities of complex inequalities by gender. Analysing the everyday workings of two hydropower development organisations in India, we show how organisational structures demonstrate a blatant culture of masculinity. These two organisations, like many others, are sites where hierarchies and inequalities based on gender are produced, performed and reproduced. This performance of masculinity promotes and rewards a culture of technical pride in re-shaping nature, abiding by and maintaining hierarchy and demonstrating physical strength and emotional hardiness. In such a setting, paying attention to vulnerabilities, inequalities and disparities are incompatible objectives.

The United Nations 2030 Agenda for Sustainable Development promises to achieve change in almost every aspect of life on Earth. Encompassing 17 Sustainable Development Goals (SDGs) and 169 targets, the Agenda marks the first time in history when all nations have agreed on how to chart their future. The SDGs are not just a global reporting exercise, however, but rather involve a global program that embraces country-led efforts. Guided by the ideas contained in the 2030 Agenda, each nation must seek to become more prosperous and sustainable, while contributing to the global effort at the same time. If all the countries achieve this, we will have a sustainable planet and a secure future for all. This document offers guidance on how developing countries can adapt the SDGs to their own contexts and priorities. It indicates important areas for developing countries to consider when creating their own program to achieve the SDGs, and provides examples of success to demonstrate concrete possibilities for progress.

The increasing demand for water, energy and food, and the interdependence of these systems could lead to potential human conflict in the future. This was seen in the food crisis of 2008, which stirred a renewed interest in taking a quot;systemsquot; approach to managing resources. The initial flurry of activities led to many nexus frameworks, but there remains a gap between theory and its implementation. This paper tries to look at various frameworks and unpacks the concept of nexus in order to develop matrices to help quantify and understand the interlinkages between the nexus systems. It suggests multi-level and multi-system indices to measure the health of nexus systems and to identify the weak links. It is hoped that such frameworks can be used at country level, and eventually be used to measure and rank countries on the health of their systems. The paper suggests a questionnaire that can be used (after modifying for local conditions) to collect country-level institutional and political-economy data (which is difficult to get from online resources) to be used in the framework.

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.

The Indus River Basin faces severe water quality degradation because of nutrient enrichment from human activities. Excessive nutrients in tributaries are transported to the river mouth, causing coastal eutrophication. This situation may worsen in the future because of population growth, economic development, and climate change. This study aims at a better understanding of the magnitude and sources of current (2010) and future (2050) river export of total dissolved nitrogen (TDN) by the Indus River at the sub-basin scale. To do this, we implemented the MARINA 1.0 model (Model to Assess River Inputs of Nutrients to seAs). The model inputs for human activities (e.g., agriculture, land use) were mainly from the GLOBIOM (Global Biosphere Management Model) and EPIC (Environmental Policy Integrated Model) models. Model inputs for hydrology were from the Community WATer Model (CWATM). For 2050, three scenarios combining Shared Socio-economic Pathways (SSPs 1, 2 and 3) and Representative Concentration Pathways (RCPs 2.6 and 6.0) were selected. A novelty of this study is the sub-basin analysis of future N export by the Indus River for SSPs and RCPs. Result shows that river export of TDN by the Indus River will increase by a factor of 1.6–2 between 2010 and 2050 under the three scenarios. N90% of the dissolved N exported by the Indus River is from midstream sub-basins. Human waste is expected to be the major source, and contributes by 66–70% to river export of TDN in 2050 depending on the scenarios. Another important source is agriculture, which contributes by 21–29% to dissolved inorganic N export in 2050. Thus a combined reduction in both diffuse and point sources in the midstream sub-basins can be effective to reduce coastal water pollution by nutrients at the river mouth of Indus.

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.

This study assesses the microbial and heavy metal distribution in African catfish (Clarias gariepinus) cultured in waste stabilization pond, and their subsequent suitability for human consumption. Treated wastewater-fed pond (WFP) was used in the culture of the fish with a non-wastewater fed pond (NWFP), fed with ground and rain water as control. Pond water, sediments and fish tissue (gill, liver, gut and skin) samples from both sources were analyzed for pathogens and heavy metal levels. Escherichia coli populations in the sediments and water from the WFP exceeded the maximum permissible limit by 2–3 log units as expected. Significantly higher levels of pathogen contamination were detected in the gut and skin of fish from the WFP than the NWFP. Heavy metal concentrations in all samples fell within the Food and Agricultural Organization (FAO)/World Health Organization (WHO) and National Oceanic and Atmospheric Administration (NOAA) permissible limits except for iron and cadmium. There were significantly higher heavy metal concentrations in gill and liver than the muscle. Even though iron recorded the highest concentrations in fish tissue, the concentrations (0.1–2.0 mg kg-1) were below the expected daily nutritional requirement (1–2 mg) for humans and pose no toxicological risk. However, catfish from WFP would require precautionary measures such as cooking/grilling prior to consumption to avoid pathogen infection.

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.

Diarrhoea caused by waterborne pathogens still has a large burden of disease. We introduce a modelling and scenario analysis framework that enables better understanding of sources of and possible future changes in the disease burden due to environmental change and management implementation. The state-of-the-art research that can contribute to the development of the framework at the large scale is analysed, together with research gaps and opportunities for future research. Priorities have been identified and these include implementation of Quantitative Microbial Risk Assessment and application of the models in scenario analyses. The credibility of the model outputs should be central in the analysis, for example by developing stochastic models. Implementation of the framework contributes towards achieving the Sustainable Development Goals.

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.

While water pollution is starting to receive the attention it deserves, the contribution of agriculture requires greater consideration as current agricultural practices have an unprecedented impact on water quality. This paper reviews knowledge in selected areas of agricultural water pollution (AWP) and identifies future research needs. These include source attribution, emerging contaminants, costs and incentives for adoption of pollution reduction measures. Future research priorities include identification and testing of locally appropriate markers; modelling the effects of contaminants on biota and pathways of microbial contaminants; harmonization of data collection and calculation of economic costs of AWP across countries and projects; and how to better share relevant knowledge to incentivize improved agricultural practices.

Globally, many populations face structural and environmental barriers to access safe water, sanitation and hygiene (WASH) services. Among these populations are many of the 200 million pastoralists whose livelihood patterns and extreme environmental settings challenge conventional WASH programming approaches. In this paper, we studied the Afar pastoralists in Ethiopia to identify WASH interventions that can mostly alleviate public health risks, within the populationapos;s structural and environmental living constraints. Surveys were carried out with 148 individuals and observational assessments made in 12 households as part of a Pastoralist Community WASH Risk Assessment. The results show that low levels of access to infrastructure are further compounded by risky behaviours related to water containment, storage and transportation. Additional behavioural risk factors were identified related to sanitation, hygiene and animal husbandry. The Pastoralist Community WASH Risk Assessment visually interprets the seriousness of the risks against the difficulty of addressing the problem. The assessment recommends interventions on household behaviours, environmental cleanliness, water storage, treatment and hand hygiene via small-scale educational interventions. The framework provides an approach for assessing risks in other marginal populations that are poorly understood and served through conventional approaches.

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.

Farmers in Minor Irrigation Systems (MIS) experience many difficulties due to severe seasonal or year-round absolute water scarcity that affects their livelihoods. In order to address this problem, the resilience of the vulnerable communities needs to be enhanced through smart investments and appropriate adaptation strategies. Since there is no well-established method for assessing the resilience of the farmers in MIS, this study was aimed to develop a framework and prospective methodology to assess resilience and factors determining the resilience to shocks and stresses of MIS. A structured questionnaire survey was carried out among 188 households belong to eight farmer organizations under 16 MIS located in three Agrarian Service Divisions in the IL3 agro-ecological region in Kurunegala District. The resilience of farming was measured using adaptive capacity or the risk management strategies used at household levels related to farming practices using 20 indicators. Analysis of factors was performed with the principle component method and rotated (from Varimax with Kaiser Normalization technique) factor loadings were extracted to compute resilience index. Using the empirical equation derived from the study, the resilience of MIS was quantitatively determined. The results showed that there is an adequate space to enhance the resilience of farming in MIS by introducing and adapting various risk management strategies. It appears that capacity of the tank, accessibility of services and the trust of farmers both on farmer organizations and the agency officials are some of the key factors which govern the resilience of farming in MIS.

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.

Current patterns of agricultural expansion and intensification are bringing unprecedented environmental externalities, including impacts on water quality. While water pollution is slowly starting to receive the attention it deserves, the contribution of agriculture to this problem has not yet received sufficient consideration. We need a much better understanding of the causes and effects of agricultural water pollution as well as effective means to prevent and remedy the problem. In the existing literature, information on water pollution from agriculture is highly dispersed. This repost is a comprehensive review and covers different agricultural sectors (including crops, livestock and aquaculture), and examines the drivers of water pollution in these sectors as well as the resulting pressures and changes in water bodies, the associated impacts on human health and the environment, and the responses needed to prevent pollution and mitigate its risks.

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.

Wastewater irrigation is a common livelihood practice in many parts of the developing world. With the continuous irrigation supply, groundwater systems in these regions perceive adverse impacts due to inadequate infrastructure to treat the wastewater. The current study area, Musi River irrigation system, is one such case study located in the peri-urban Hyderabad of South India. The Musi River water, which is used for irrigation, is composed of untreated and secondary treated wastewater from Hyderabad city. Kachiwani Singaram micro-watershed in the peri-urban Hyderabad is practicing wastewater irrigation for the last 40 years. The current quality of (untreated) wastewater used for irrigation is expected to have adverse impacts on the local aquifers, but detailed investigations are lacking. To elucidate the groundwater quality dynamics and seasonality of the wastewater irrigation impacts on the peri-urban agricultural system, we analyzed the groundwater quality on a monthly basis for one hydrological year in the wastewater and groundwater irrigated areas, which exist next to each other. The spatio-temporal variability of groundwater quality in the watershed was analyzed with respect to wastewater irrigation and seasonality using multivariate statistical analysis, multi-way modeling and self-organizing maps. This study indicates the significance of combining various statistical techniques for detailed evaluation of the groundwater processes in a wastewater irrigated agricultural system. The results suggest that concentrations of the major ionic substances increase after the monsoon season, especially in wastewater irrigated areas. Multi-way modeling identified the major polluted groundwaters to come from the wastewater irrigated parts of the watershed. Clusters of chemical variables identified by using self-organizing maps indicate that groundwater pollution is highly impacted by mineral interactions and long-term wastewater irrigation. The study recommends regular monitoring of water resources and development of sustainable management strategies to mitigate the aquifer pollution in wastewater irrigation systems.

The discourse on the need for water, energy, and food security has dominated the development agenda of southern African countries, centred on improving livelihoods, building resilience, and regional integration. About 60% of the population in the Southern African Development Community (SADC) live in rural areas relying mainly on rainfed agriculture, lacking access to clean water and energy, yet the region is endowed with vast natural resources. The water-energy-food (WEF) nexus is a conceptual framework that presents opportunities for greater resource coordination, management, and policy convergence across sectors. This is particularly relevant in the SADC region as resources are transboundary and supports efforts linked to regional integration and inclusive socio-economic development and security. We conducted an appraisal of WEF-related policies and institutions in SADC and identified linkages among them. The present ‘silo’ approach in resource management and allocation, often conducted at the national level, contributes to the region’s failure to meet its development targets, exacerbating its vulnerabilities. The lack of coordination of WEF nexus synergies and trade-offs in planning often threatens the sustainability of development initiatives. We highlighted the importance of the WEF nexus to sustainably address the sectoral coordination of resources through harmonised institutions and policies, as well as setting targets and indicators to direct and monitor nexus developments. We illustrate the significance of the nexus in promoting inclusive development and transforming vulnerable communities into resilient societies. The study recommends a set of integrated assessment models to monitor and evaluate the implementation of WEF nexus targets. Going forward, we propose the adoption of a regional WEF nexus framework.

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.