Water, Land and Ecosystems - Zimbabwe

Poster on ecosystem services for agriculture development: a new way to look at sustainability

Anonymous — Thu, 19 Nov 2020 22:02:41 +0000

TypePoster

Subjects

Agricultural production
Ecosystems
Intensification
Land Management

Languageen

Authors

CGIAR Research Program on Water, Land and Ecosystems

Citation

CGIAR Research Program on Water, Land and Ecosystems (WLE). 2013. Ecosystem services for agriculture development: a new way to look at sustainability.

Accessibility

Open Access

Permalink

https://hdl.handle.net/10568/34774

Solutions

Groundwater availability and use in Sub-Saharan Africa: a review of 15 countries

Anonymous — Thu, 19 Nov 2020 22:02:41 +0000

Regions

Southern Africa

TypeBook

Languageen

Authors

Pavelic, Paul
Giordano, Mark
Keraita, Bernard N.
Ramesh, Vidya
Rao, Tamma

Traditionally, the spread and extent of human settlement beyond the major riparian zones of Sub-Saharan Africa (SSA) and across many other arid regions of the world, has been determined by availability of groundwater supplies, accessed through hand-dug wells andsprings. In more recent times, groundwater is the preferred means of supplying water to meet the growing demand of the rural, dispersed communities and the small urban towns across SSA. It is estimated that about 100 million of the rural population throughout SSA areserviced by groundwater for domestic supplies and livestock rearing (Adelana and MacDonald, 2008), with most of the villages and small towns having access to groundwater supplies (Masiyandima and Giordano, 2007).

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Citation

Pavelic P, Giordano M, Keraita B, Ramesh V, Rao T, eds. 2012. Groundwater availability and use in Sub-Saharan Africa: a review of 15 countries. Colombo, Sri Lanka: International Water Management Institute (IWMI).

Accessibility

Open Access

Permalink

https://hdl.handle.net/10568/33844

Soyabean response to rhizobium inoculation across sub-Saharan Africa: Patterns of variation and the role of promiscuity

Anonymous — Thu, 19 Nov 2020 22:02:41 +0000

Regions

Middle Africa
Southern Africa

TypeJournal Article

Languageen

Authors

Heerwaarden, Joost van
Baijukya, Frederick P.
Kyei-Boahen, S.
Adjei-Nsiah, Samuel
Ebanyat, Peter
Kamai, N.
Woldemeskel, Endalkachew
Kanampiu, F.K.
Vanlauwe, Bernard
Giller, Ken E.

Improving bacterial nitrogen fixation in grain legumes is central to sustainable intensification of agriculture in sub-Saharan Africa. In the case of soyabean, two main approaches have been pursued: first, promiscuous varieties were developed to form effective symbiosis with locally abundant nitrogen fixing bacteria. Second, inoculation with elite bacterial strains is being promoted. Analyses of the success of these approaches in tropical smallholder systems are scarce. It is unclear how current promiscuous and non-promiscuous soyabean varieties perform in inoculated and uninoculated fields, and the extent of variation in inoculation response across regions and environmental conditions remains to be determined. We present an analysis of on-farm yields and inoculation responses across ten countries in Sub Saharan Africa, including both promiscuous and non-promiscuous varieties. By combining data from a core set of replicated on-farm trials with that from a large number of farmer-managed try-outs, we study the potential for inoculation to increase yields in both variety types and evaluate the magnitude and variability of response. Average yields were estimated to be 1343 and 1227 kg/ha with and without inoculation respectively. Inoculation response varied widely between trials and locations, with no clear spatial patterns at larger scales and without evidence that this variation could be explained by yield constraints or environmental conditions. On average, specific varieties had similar uninoculated yields, while responding more strongly to inoculation. Side-by side comparisons revealed that stronger responses were observed at sites where promiscuous varieties had superior uninoculated yields, suggesting the availability of compatible, effective bacteria as a yield limiting factor and as a determinant of the magnitude of inoculation response.

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Citation

van Heerwaarden, J., Baijukya, F., Kyei-Boahen, S., Adjei-Nsiah, S., Ebanyat, P., Kamai, N., ... & Giller, K. (2018). Soyabean response to rhizobium inoculation across sub-Saharan Africa: patterns of variation and the role of promiscuity. Agriculture, Ecosystems & Environment, 261, 211-218.

Accessibility

Open Access

Permalink

https://hdl.handle.net/10568/88072

A hybrid approach to decolonize formal water law in Africa

Anonymous — Thu, 19 Nov 2020 22:02:41 +0000

TypeReport

Languageen

Authors

Koppen, Barbara C.M. van
Schreiner, B.

In recent decades, many countries in sub-Saharan Africa have pursued national water permit systems, derived from the colonial era and reinforced by “global best practice.” These systems have proved logistically impossible to manage and have worsened inequality in water access. A new study conducted by the International Water Management Institute (IWMI) and Pegasys Institute, with support from the UK government, traces the origins of these systems, and describes their implementation and consequences for rural smallholders in five countries – Kenya, Malawi, South Africa, Uganda and Zimbabwe. The authors of this report propose a hybrid water use rights system to decolonize Africa’s water law, lighten the administrative burden on the state and make legal access to water more equitable. This would strengthen smallholder irrigation, which is vital for boosting Africa’s food production and making it more resilient in the face of worsening drought.

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Citation

van Koppen, Barbara; Schreiner, B. 2018. A hybrid approach to decolonize formal water law in Africa. Colombo, Sri Lanka: International Water Management Institute (IWMI).. 45p. (IWMI Research Report 173) doi: 10.5337/2018.219

Accessibility

Open Access

Permalink

https://hdl.handle.net/10568/97845

Global change and investments in smallholder irrigation for food and nutrition security in Sub-Saharan Africa

Anonymous — Thu, 19 Nov 2020 22:02:41 +0000

Regions

Southern Africa

TypeBook Chapter

Languageen

Authors

Hanjra, Munir A.
Williams, Timothy O.

Investments in irrigation contribute to poverty reduction and enhance food security. This paper considers irrigation investments more broadly in the context of rural–urban linkages and thus examines rural irrigation schemes and peri-urban and urban agriculture using freshwater, groundwater and wastewater. We present case studies from East, West and Southern Africa, while focusing on the imperative of smallholders and of food security and nutrition. Evidence from Big Data and telecoupling show that, amid global change and sustainability issues, irrigation development strengthens connections between humans and nature with notable benefits to food security. Transforming investments to feed the future generation require priority investments in irrigation, solar energy for groundwater pumping, groundwater development policy, and integration of peri-urban and urban agriculture into food systems. Equally important will be no-regret interventions in wastewater reuse, water storage and groundwater buffer, micro-irrigation, and wholesale reconfiguration of farming systems, through anticipatory investments, to safeguard food security and sustainability into the distant future.

Citation

Hanjra, Munir A.; Williams, Timothy O. 2020. Global change and investments in smallholder irrigation for food and nutrition security in Sub-Saharan Africa. In Gomez y Paloma, S.; Riesgo, L.; Louhichi, K. (Eds.). The role of smallholder farms in food and nutrition security. Cham, Switzerland: Springer. pp.99-131.

Accessibility

Open Access

Permalink

https://hdl.handle.net/10568/108358

Estimating biomass of savanna grasslands as a proxy of carbon stock using multispectral remote sensing

Anonymous — Thu, 19 Nov 2020 22:02:41 +0000

TypeJournal Article

Languageen

Authors

Chapungu, L.
Nhamo, Luxon
Gatti, R.C.

Limited research has been done to estimate the root biomass (belowground biomass) of savanna grasslands. The advent of remote sensing and related products have facilitated the estimation of biomass in terrestrial ecosystems, providing a synoptic overview on ecosystems biomass. Multispectral remote sensing was used in this study to estimate total biomass (belowground and aboveground) of selected tropical savanna grassland species. Total biomass was estimated by assessing the relationship between aboveground and belowground biomass, the Normalised Difference Vegetation Index (NDVI) and belowground biomass, and NDVI and total biomass. Results showed a positive significant relationship (p ¼ 0.005) between belowground and aboveground biomass. NDVI was significantly correlated (p ¼ 0.0386) to aboveground biomass and the Root Mean Square Error (RMSE) was 18.97 whilst the model BIAS was 0.019, values within acceptable ranges. A significant relationship (p ¼ 0) was found between belowground biomass and NDVI and the RMSE was 5.53 and the model BIAS was 0.0041. More so, a significant relationship (p ¼ 0.054) was observed between NDVI and total biomass. The positive relationships between NDVI and total grass biomass and the lack of bias in the model provides an opportunity to routinely monitor carbon stock and assess seasonal carbon storage fluctuations in grasslands. There is great potential in the ability of remote sensing to become an indispensable tool for assessing, monitoring and inventorying carbon stocks in grassland ecosystems under tropical savanna conditions.

Citation

Chapungu, L.; Nhamo, Luxon; Gatti, R. C. 2020. Estimating biomass of savanna grasslands as a proxy of carbon stock using multispectral remote sensing. Remote Sensing Applications: Society and Environment, 17:100275. doi: 10.1016/j.rsase.2019.100275

Accessibility

Limited Access

Research Themes

Restoring Degraded Landscapes

Permalink

https://hdl.handle.net/10568/106471

The politics of IWRM in southern Africa

Anonymous — Thu, 19 Nov 2020 22:02:41 +0000

Regions

Southern Africa

TypeJournal Article

Languageen

Authors

Mehta, L.
Alba, R.
Bolding, A.
Denby, K.
Derman, A.
Hove, T.
Manzungu, Emmanuel
Movik, S.
Prabhakaran, P.
Koppen, Barbara C.M. van

This article offers an approach to the study of the evolution, spread and uptake of integrated water resources management (IWRM). Specifically, it looks at the flow of IWRM as an idea in international and national fora, its translation and adoption into national contexts, and the on-the-ground practices of IWRM. Research carried out in South Africa, Zimbabwe and Mozambique provides empirical insights into the politics of IWRM implementation in southern Africa, the interface between international and national interests in shaping water policies in specific country contexts, and the on-theground challenges of addressing equity, redress and the reallocation of water.

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Citation

Mehta, L.; Alba, R.; Bolding, A.; Denby, K.; Derman, A.; Hove, T.; Manzungu, E.; Movik, S.; Prabhakaran, P.; van Koppen, Barbara. 2014. The politics of IWRM in southern Africa. International Journal of Water Resources Development, 30(3):528-542. doi: https://dx.doi.org/10.1080/07900627.2014.916200

Accessibility

Open Access

Permalink

https://hdl.handle.net/10568/77501

Climate Change Impacts on Water Availability and Use in the Limpopo River Basin

Anonymous — Thu, 19 Nov 2020 22:02:41 +0000

Regions

Southern Africa

TypeJournal Article

Subjects

Modelling and spatial analysis
Hydrology/hydrogeology
Climate change
Impact
River basins
Irrigation

Languageen

Authors

Zhu, T.
Ringler, Claudia

This paper analyzes the effects of climate change on water availability and use in the Limpopo River Basin of Southern Africa, using a linked modeling system consisting of a semi-distributed global hydrological model and the Water Simulation Module (WSM) of the International Model for Policy Analysis of Agricultural Commodities and Trade (IMPACT). Although the WSM simulates all major water use sectors, the focus of this study is to evaluate the implications of climate change on irrigation water supply in the catchments of the Limpopo River Basin within the four riparian countries: Botswana, Mozambique, South Africa, and Zimbabwe. The analysis found that water resources of the Limpopo River Basin are already stressed under today�s climate conditions. Projected water infrastructure and management interventions are expected to improve the situation by 2050 if current climate conditions continue into the future. However, under the climate change scenarios studied here, water supply availability is expected to worsen considerably by 2050. Assessing hydrological impacts of climate change is crucial given that expansion of irrigated areas has been postulated as a key adaptation strategy for Sub-Saharan Africa. Such expansion will need to take into account future changes in water availability in African river basins.

Citation

Zhu, T. and C. Ringler. 2012. Climate Change Impacts on Water Availability and Use in the Limpopo River Basin. Water 4(1): 63-84.

Accessibility

Open Access

Research Themes

Variability, Risks and Competing Uses

Permalink

https://hdl.handle.net/10568/34687

Solutions

Hydrological impacts of urbanization of two catchments in Harare, Zimbabwe

Anonymous — Thu, 19 Nov 2020 22:02:41 +0000

TypeJournal Article

Languageen

Authors

Gumindoga, W.
Rientjes, T.H.M.
Shekede, M.D.
Rwasoka, D.T.
Nhapi, I.
Haile, Alemseged Tamiru

By increased rural-urban migration in many African countries, the assessment of changes in catchment hydrologic responses due to urbanization is critical for water resource planning and management. This paper assesses hydrological impacts of urbanization on two medium-sized Zimbabwean catchments (Mukuvisi and Marimba) for which changes in land cover by urbanization were determined through Landsat Thematic Mapper (TM) images for the years 1986, 1994 and 2008. Impact assessments were done through hydrological modeling by a topographically driven rainfall-runoff model (TOPMODEL). A satellite remote sensing based ASTER 30 metre Digital Elevation Model (DEM) was used to compute the Topographic Index distribution, which is a key input to the model. Results of land cover classification indicated that urban areas increased by more than 600 % in the Mukuvisi catchment and by more than 200 % in the Marimba catchment between 1986 and 2008. Woodlands decreased by more than 40% with a greater decrease in Marimba than Mukuvisi catchment. Simulations using TOPMODEL in Marimba and Mukuvisi catchments indicated streamflow increases of 84.8 % and 73.6 %, respectively, from 1980 to 2010. These increases coincided with decreases in woodlands and increases in urban areas for the same period. The use of satellite remote sensing data to observe urbanization trends in semi-arid catchments and to represent catchment land surface characteristics proved to be effective for rainfall-runoff modeling. Findings of this study are of relevance for many African cities, which are experiencing rapid urbanization but often lack planning and design.

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Citation

Gumindoga, W.; Rientjes, T.; Shekede, M. D.; Rwasoka, D. T.; Nhapi, I.; Haile, Alemseged Tamiru. 2014. Hydrological impacts of urbanization of two catchments in Harare, Zimbabwe. Remote Sensing, 6(12):12544-12574. doi: https://dx.doi.org/10.3390/rs61212544

Accessibility

Open Access

Permalink

https://hdl.handle.net/10568/77507

Decentralising Zimbabwe's water management: the case of Guyu-Chelesa irrigation scheme

Anonymous — Thu, 19 Nov 2020 22:02:41 +0000

Regions

Southern Africa

TypeJournal Article

Languageen

Authors

Tambudzai, R.
Mapedza, Everisto
Gideon, Z.

Smallholder irrigation schemes are largely supply driven such that they exclude the beneficiaries on the management decisions and the choice of the irrigation schemes that would best suit their local needs. It is against this background that the decentralisation framework and the Dublin Principles on Integrated Water Resource Management (IWRM) emphasise the need for a participatory approach to water management. The Zimbabwean government has gone a step further in decentralising the management of irrigation schemes, that is promoting farmer managed irrigation schemes so as to ensure effective management of scarce community based land and water resources. The study set to investigate the way in which the Guyu-Chelesa irrigation scheme is managed with specific emphasis on the role of the Irrigation Management Committee (IMC), the level of accountability and the powers devolved to the IMC. Merrey's 2008 critique of IWRM also informs this study which views irrigation as going beyond infrastructure by looking at how institutions and decision making processes play out at various levels including at the irrigation scheme level. The study was positioned on the hypothesis that 'decentralised or autonomous irrigation management enhances the sustainability and effectiveness of irrigation schemes'. To validate or falsify the stated hypothesis, data was gathered using desk research in the form of reviewing articles, documents from within the scheme and field research in the form of questionnaire surveys, key informant interviews and field observation. The Statistical Package for Social Sciences was used to analyse data quantitatively, whilst content analysis was utilised to analyse qualitative data whereby data was analysed thematically. Comparative analysis was carried out as Guyu-Chelesa irrigation scheme was compared with other smallholder irrigation scheme's experiences within Zimbabwe and the Sub Saharan African region at large. The findings were that whilst the scheme is a model of a decentralised entity whose importance lies at improving food security and employment creation within the community, it falls short in representing a downwardly accountable decentralised irrigation scheme. The scheme is faced with various challenges which include its operation which is below capacity utilisation, absence of specialised technical human personnel to address infrastructural breakdowns, uneven distribution of water pressure, incapacitated Irrigation Management Committee (IMC), absence of a locally legitimate constitution, compromised beneficiary participation and unclear lines of communication between various institutions involved in water management. Understanding decentralization is important since one of the key tenets of IWRM is stakeholder participation which the decentralization framework interrogates.

Citation

Tambudzai, R.; Mapedza, Everisto; Gideon, Z. 2013. Decentralising Zimbabwe?s water management: the case of Guyu-Chelesa irrigation scheme. Physics and Chemistry of the Earth, 66:139-147. doi: https://dx.doi.org/10.1016/j.pce.2013.08.005

Accessibility

Limited Access

Research Themes

Land and Water Solutions for Sustainable Agriculture

Permalink

https://hdl.handle.net/10568/40317