Your search found 39 records
1 McCartney, Matthew; Cai, Xueliang; Smakhtin, Vladimir; Nhamo, Luxon. 2011. Application of a quantitative method to evaluate flow regulating functions of ecosystems in the Zambezi Basin. Project report submitted to UNEP under the SADC project "Dam Synchronization and Flood Releases in the Zambezi River Basin". Addis Ababa, Ethiopia: International Water Management Institute (IWMI). 46p.
River basins ; Ecosystems ; Flow ; Regulation ; forests ; Floodplains ; Wetlands ; Swamps ; Hydrology ; Time series analysis ; Maps ; Catchment areas / Southern Africa / Angola / Botswana / Malawi / Mozambique / Namibia / Tanzania / Zambia / Zimbabwe / Zambezi River Basin
(Location: IWMI HQ Call no: e-copy only Record No: H044606)
(5.40 MB)
By affecting transpiration and evaporation and influencing how water is routed and stored in a basin, forests, wetlands and floodplains play a crucial role in the hydrological cycle. Although they are widely attributed a major role in regulating flows (i.e. both attenuating floods and maintaining flow during dry periods) these services are seldom, if ever, explicitly factored into the planning and management of water resources. One reason for the failure to include them is lack of understanding of the hydrological functions occurring, their dynamic nature, and the interaction of those functions with the catchments in which the ecosystems are located. Very often it is unclear exactly which functions are performed and how those functions change over time (i.e. between seasons and between years). Furthermore, both the lack of quantitative information and a recognized method to incorporate them into decision-making processes, make it very difficult to integrate natural hydrological functions into the planning and management of water resources. This report describes a pragmatic approach for quantifying the flow regulating functions of floodplains, headwater wetlands and forests in the Zambezi Basin. The method utilizes observed stream flow records and flow duration curves to derive a simulated time series of flow in the absence of the ecosystem. This can then be compared with an observed time series to evaluate the impact of the ecosystem on the flow regime. The method, which is easy to utilize and could easily be incorporated into a decision support system for the synchronization of dam operation, has been applied and results obtained for 16 locations in the basin. Results indicate that the different ecosystems affect flows in different and complex ways. Broadly: i) floodplains decrease flood flows and increase low flows; ii) headwater wetlands increase flood flows and decrease low flows; iii) miombo forest, when covering more than 70% of the catchment, decreases flood flows and decreases low flows. However, in all cases there are examples which produce contrary results and simple relationships between the extent of an ecosystem type within a catchment and the impact on the flow regime were not found.
2 Nhamo, Luxon; Chilonda, Pius. 2012. Water and agriculture vulnerability to climate change and adaptive capacity in southern Africa. Paper presented at the WISA (Water Institute of Southern Africa) Biennial conference on Water Footprints, Cape Town, South Africa, 6-10 May 2012. 9p.
Water management ; Agricultural production ; Water availability ; Water scarcity ; Water harvesting ; Climate change ; Drought ; Flooding ; Livestock ; GIS ; Living conditions / Southern Africa / SADC Region
(Location: IWMI HQ Call no: e-copy only Record No: H044969)
http://www.ewisa.co.za/literature/files/ID60%20Paper46%20Nhamo%20L.pdf
https://vlibrary.iwmi.org/pdf/H044969.pdf
https://vlibrary.iwmi.org/pdf/H044969.pdf
(0.30 MB) (304.47KB)
Increasing temperatures and declining rainfall patterns as well as increasing frequency of extreme climate events such as droughts and floods are the expected future weather patterns within the tropics. Africa, particularly Southern Africa, is projected to be the region most vulnerable to the impacts of climate variability and change especially in agriculture and water. This has dire consequences as most people in Southern Africa depend on agriculture for their livelihoods. While much of climate change studies have been done at global scale, the impacts of climate change and variability will be felt locally at household, community, national and regional levels. In most cases daptation occurs at local level in ways that are usually unnoticed and unaided by national governments or international organisations. This paper down-scales the vulnerability of and adaptive capacity to climate change and variability to local level (household, community, national and regional) applying the Household Economy Approach (HEA). The focus is on local dimensions of climate change impact on water availability and agriculture productivity in Southern Africa, but taking only a sample of the region. In addition, an assessment of the factors that determine the capacity of local communities to deal with current and future climate changes and variability is made. Adaptive measures are also recommended, paying special attention to the role of local institutions in adapting to climate change. This paper emphasises the importance of ensuring that farmers have access to relevant knowledge and information on the effects of climate variability and change in order to enhance their adaptive capacity.
3 Nhamo, Luxon; Chilonda, Pius. 2012. Climate change risk and vulnerability mapping and profiling at local level using the Household Economy Approach (HEA) Earth Science and Climatic Change, 3(3):7p. [doi: https://doi.org/10.4172/2157-7617.1000123]
Climate change ; Risks ; Mapping ; Water scarcity ; Drought ; Flooding ; Temperature ; Rainfed farming ; Crop production ; Households ; Economic aspects / Africa South of Sahara
(Location: IWMI HQ Call no: e-copy only Record No: H045472)
http://omicsonline.org/2157-7617/pdfdownload.php?download=2157-7617-3-123.pdf&&aid=9786
https://vlibrary.iwmi.org/pdf/h045472.pdf
https://vlibrary.iwmi.org/pdf/h045472.pdf
(2.15 MB) (2.15MB)
The increasing frequency of extreme climate events such as droughts and floods, as well as increasing temperatures and declining rainfall, are the expected future weather patterns of climate change hot spots such as Sub-Saharan Africa. Climate change and variability hot spot areas will be most vulnerable to diminishing crop production and water resources as most people in these areas depend on rainfed agriculture for their livelihoods. While much of climate change studies have been done at global scale, the impacts of climate change and variability will be felt locally at community level. In most cases adaptation occurs at local level in ways that are usually unnoticed and unaided by national governments or international organisations. This study down-scales the vulnerability of and adaptive capacity to climate change and variability to local level applying the Household Economy Approach. The focus is on local dimensions of climate change impact on water and agriculture in Western Zambia. A climate change vulnerability zone map is delineated using GIS, and a detailed profile of the zones is presented. The focus is on how communities cope with comparable climate change risks that occur today, like droughts, floods and pests, and then gauge their capacity to mitigate future CC shocks. Some adaptive measures that can be adopted to mitigate climate change impacts are recommended. The results equip policy makers with information on the impacts of climate change at local level, and capacitate them with a tool to make informed intervention.
4 Nhamo, Luxon; Christopher, M.; Chilonda, Pius. 2013. Validating the Soil Conservation Service Triangular Unit Hydrograph (SCS-TUH) model in estimating runoff peak discharge of a catchment in Masvingo, Zimbabwe. International Journal of Water Resources and Environmental Engineering, 5(3):157-162. [doi: https://doi.org/10.5897/IJWREE12.085]
Soil Conservation ; Models ; Runoff ; Catchment areas ; Flow discharge ; Water management ; Water availability ; Water allocation ; Water balance / Zimbabwe / Masvingo
(Location: IWMI HQ Call no: e-copy only Record No: H045767)
http://www.academicjournals.org/ijwree/PDF/Pdf2013/Mar/Luxon%20et%20al.pdf
https://vlibrary.iwmi.org/pdf/H045767.pdf
https://vlibrary.iwmi.org/pdf/H045767.pdf
(0.42 MB) (426.79KB)
The knowledge of runoff discharged by a catchment at its outlet is important for water accounting and water allocation to competing uses. Runoff generated by a catchment is important in determining the catchment water balance, estimating pollutant loads, and quantifying sediment yield and delivery ratio. The Soil Conservation Service triangular unit hydrograph (SCS-TUH) model was used in this study to simulate water discharged into Siya Dam from Rosva River Catchment in Masvingo Province, Zimbabwe. The SCS-TUH model is preferred because it takes into consideration the physical and hydrological conditions of a catchment, as well, as the volume and flow variations of the entire rainfall event. The model simulates the peak runoff rate of a catchment using daily rainfall data. An overview of the methodology and the different steps followed are given. The model results were validated by comparing the simulated values with measured values recorded from a gauging station at the catchment outlet. The plotted hydrographs of both simulated and measured values coincided very well in height as well as in shape with great precision. The results showed that the SCS-TUH model can be used for simulating runoff discharge in ungauged catchments in the region.
5 Nhamo, Luxon; Chilonda, Pius. 2013. Validation of the rainfall-runoff SCS-CN model in a catchment with limited measured data in Zimbabwe. International Journal of Water Resources and Environmental Engineering, 5(6):295-303. [doi: https://doi.org/10.5897/IJWREE12.114]
Rainfall-runoff relationships ; Soil conservation ; Simulation models ; Catchment areas ; Dams ; Irrigation schemes ; Water availability ; Water balance / Zimbabwe
(Location: IWMI HQ Call no: e-copy only Record No: H045849)
http://www.academicjournals.org/ijwree/PDF/Pdf2013/June/Nhamo%20and%20Chilonda.pdf
https://vlibrary.iwmi.org/pdf/H045849.pdf
https://vlibrary.iwmi.org/pdf/H045849.pdf
(0.57 MB) (580.85KB)
An evaluation of available opportunities to revive irrigation on a long abandoned irrigation scheme in a dry region of Zimbabwe is presented by assessing water availability at catchment level. The aim is to enhance the livelihoods, income and nutrition of the communities that depend on the irrigation scheme through a sustainable management of revitalised irrigation infrastructure and ensure food security. Runoff generated in the catchment, with potential to flow into the dam that supplies water to the scheme, is estimated using the Soil Conservation Service curve number (SCS-CN) model. The model simulates runoff at catchment level using daily rainfall data. An overview of the methodology and the various steps followed are provided. Daily rainfall and dam water levels are the only measured data available for the catchment. The dam water levels are used to determine the dam water volumes using rating tables. The dam water volumes are used to calculate the daily water inflows into the dam and these are compared with simulated water discharge rates obtained from the model. The plotted hydrographs of both simulated and measured values coincided very well in shape with great precision validating the SCS-CN model for simulating runoff in ungauged catchments.
6 Kibret, S.; Lautze, Jonathan; McCartney, Matthew; Wilson, G. G.; Nhamo, Luxon. 2015. Malaria impact of large dams in sub-Saharan Africa: maps, estimates and predictions. Malaria Journal, 14:1-12. [doi: https://doi.org/10.1186/s12936-015-0873-2]
Malaria ; Dams ; Reservoirs ; Risk management ; Climate change ; Case studies / Africa South of Sahara
(Location: IWMI HQ Call no: e-copy only Record No: H047178)
http://www.malariajournal.com/content/pdf/s12936-015-0873-2.pdf
https://vlibrary.iwmi.org/pdf/H047178.pdf
https://vlibrary.iwmi.org/pdf/H047178.pdf
(2.42 MB) (503 KB)
Background: While there is growing recognition of the malaria impacts of large dams in sub-Saharan Africa, the cumulative malaria impact of reservoirs associated with current and future dam developments has not been quantified. The objective of this study was to estimate the current and predict the future impact of large dams on malaria in different eco-epidemiological settings across sub-Saharan Africa.
Methods: The locations of 1268 existing and 78 planned large dams in sub-Saharan Africa were mapped against the malaria stability index (stable, unstable and no malaria). The Plasmodium falciparum infection rate (PfIR) was determined for populations at different distances (<1, 1–2, 2–5, 5–9 km) from the associated reservoirs using the Malaria Atlas Project (MAP) and WorldPop databases. Results derived from MAP were verified by comparison with the results of detailed epidemiological studies conducted at 11 dams.
Results: Of the 1268 existing dams, 723 are located in malarious areas. Currently, about 15 million people live in close proximity (<5 km) to the reservoirs associated with these dams. A total of 1.1 million malaria cases annually are associated with them: 919,000 cases due to the presence of 416 dams in areas of unstable transmission and 204,000 cases due to the presence of 307 dams in areas of stable transmission. Of the 78 planned dams, 60 will be located in malarious areas and these will create an additional 56,000 cases annually. The variation in annual PfIR in communities as a function of distance from reservoirs was statistically significant in areas of unstable transmission but not in areas of stable transmission.
Conclusion: In sub-Saharan Africa, dams contribute significantly to malaria risk particularly in areas of unstable transmission. Additional malaria control measures are thus required to reduce the impact of dams on malaria.
Methods: The locations of 1268 existing and 78 planned large dams in sub-Saharan Africa were mapped against the malaria stability index (stable, unstable and no malaria). The Plasmodium falciparum infection rate (PfIR) was determined for populations at different distances (<1, 1–2, 2–5, 5–9 km) from the associated reservoirs using the Malaria Atlas Project (MAP) and WorldPop databases. Results derived from MAP were verified by comparison with the results of detailed epidemiological studies conducted at 11 dams.
Results: Of the 1268 existing dams, 723 are located in malarious areas. Currently, about 15 million people live in close proximity (<5 km) to the reservoirs associated with these dams. A total of 1.1 million malaria cases annually are associated with them: 919,000 cases due to the presence of 416 dams in areas of unstable transmission and 204,000 cases due to the presence of 307 dams in areas of stable transmission. Of the 78 planned dams, 60 will be located in malarious areas and these will create an additional 56,000 cases annually. The variation in annual PfIR in communities as a function of distance from reservoirs was statistically significant in areas of unstable transmission but not in areas of stable transmission.
Conclusion: In sub-Saharan Africa, dams contribute significantly to malaria risk particularly in areas of unstable transmission. Additional malaria control measures are thus required to reduce the impact of dams on malaria.
7 Kumwenda, Ian; van Koppen, Barbara; Matete, Mampiti; Nhamo, Luxon. 2015. Trends and Outlook: Agricultural Water Management in southern Africa. Country report - Malawi. [Project report submitted to United States Agency for International Development’s (USAID’s) Feed the Future Program]. Pretoria, South Africa: International Water Management Institute (IWMI). 52p.
Agriculture ; Water management ; Sustainability ; Water resources ; Water policy ; Climate change ; Irrigation development ; Public investment ; Donors ; Nongovernmental organizations ; Irrigated land ; Irrigation schemes ; Water supply ; Self help ; Agroindustrial sector ; Living standards ; Farmers ; Poverty ; Case studies / Southern Africa / Malawi / Lilongwe / Salima / Ngolowindo Irrigation Scheme / Tapempha Farm Irrigation Scheme
(Location: IWMI HQ Call no: e-copy only Record No: H047386)
(1.92 MB)
8 Nhamo, Luxon. 2015. Trends and Outlook: Agricultural Water Management in southern Africa. SADC AgWater profiles. [Project report submitted to United States Agency for International Development’s (USAID’s) Feed the Future Program]. Pretoria, South Africa: International Water Management Institute (IWMI). 55p.
Agricultural production ; Water management ; Water use ; Water resources ; Irrigation efficiency ; Water supply ; Land resources ; Irrigated land ; Population ; SADC countries / Southern Africa / Angola / Botswana / Democratic Republic of the Congo / Lesotho / Malawi / Mozambique / Namibia / South Africa / Swaziland / Tanzania / Zambia / Zimbabwe
(Location: IWMI HQ Call no: e-copy only Record No: H047388)
(1.38 MB)
9 Mabhaudhi, T.; Mpandeli, S.; Madhlopa, A.; Modi, A. T.; Backeberg, G.; Nhamo, Luxon. 2016. Southern Africa’s water-energy nexus: towards regional integration and development. Water, 8(6):1-21. [doi: https://doi.org/10.3390/w8060235]
Policy making ; Sustainable development ; Regional development ; Water resources ; Energy resources ; Energy generation ; Agriculture ; Watercourses ; Water scarcity ; Water supply ; Water requirements ; International waters ; River basins ; Poverty ; Economic development ; Riparian zones ; Population growth / Africa
(Location: IWMI HQ Call no: e-copy only Record No: H047590)
(2.21 MB)
The Southern African Development Community’s (SADC) water and energy sectors are under increasing pressure due to population growth and agricultural and industrial development. Climate change is also negatively impacting on the region’s water and energy resources. As the majority of SADC’s population lives in poverty, regional development and integration are underpinned by water and energy security as the watercourses in the region are transboundary in nature. This paper reviews the region’s water and energy resources and recommends policies based on the water–energy nexus approach. This is achieved by reviewing literature on water and energy resources as well as policy issues. Water resources governance provides a strong case to create a water–energy nexus platform to support regional planning and integration as SADC countries share similar climatic and hydrological conditions. However, there has been a gap between water and energy sector planning in terms of policy alignment and technical convergence. These challenges hinder national policies on delivering economic and social development goals, as well as constraining the regional goal of greater integration. Regional objectives on sustainable energy and access to clean water for all can only be achieved through the recognition of the water–energy nexus, championed in an integrated and sustainable manner. A coordinated regional water–energy nexus approach stimulates economic growth, alleviates poverty and reduces high unemployment rates. The shared nature of water and energy resources requires far more transboundary water–energy nexus studies to be done in the context of regional integration and policy formulation.
10 Nhamo, Luxon; Matchaya, Greenwell; Nhemachena, Charles; van Koppen, Barbara. 2016. The impact of investment in smallholder irrigation schemes on irrigation expansion and crop productivity in Malawi. African Journal of Agricultural and Resource Economics, 11(2):141-153.
Irrigation schemes ; Irrigation systems ; Crop production ; Investment ; Smallholders ; Farmers ; Rainfed farming ; Agriculture ; Water resources ; Climate change ; Drought ; Food security ; Households ; Maize ; Rice ; Irrigated land ; Nutrition ; Impact assessment / Malawi / Africa South of Sahara
(Location: IWMI HQ Call no: e-copy only Record No: H047598)
http://www.afjare.org/resources/issues/vol_11_no2/5%20Nhamo%20et%20al.pdf
https://vlibrary.iwmi.org/pdf/H047598.pdf
https://vlibrary.iwmi.org/pdf/H047598.pdf
(358.81 KB)
Reliance on rainfall for agriculture and increased climate change and variability pose growing production risks in developing countries. Agriculture in Sub-Saharan Africa is dominated by smallholder farmers who depend mainly on rain-fed agriculture, putting food security at both household and national levels at risk, especially in the event of drought. Investment in smallholder irrigation becomes a priority in developing countries if food security and national development goals are to be met, as their economies are agro-based. This study evaluates the impact of investment in smallholder irrigation schemes in Malawi on improving crop production and productivity in comparison with rain-fed agriculture. The area under smallholder irrigation schemes increased from 15 988 ha in 2003 to about 42 986 ha in 2011, contributing immensely to national food production. Irrigated maize production increased from 78 159 tons in 2000 to 544 378 tons in 2013.
11 Kibret, S.; Lautze, Jonathan; McCartney, Matthew; Nhamo, Luxon; Wilson, G. G. 2016. Malaria and large dams in sub-Saharan Africa: future impacts in a changing climate. Malaria Journal, 15:1-14. [doi: https://doi.org/10.1186/s12936-016-1498-9]
Malaria ; Dams ; Reservoirs ; Climate change ; Public health ; Health hazards ; Disease prevention ; Population growth ; Sociocultural environment / Africa South of Sahara
(Location: IWMI Call no: e-copy only Record No: H047719)
https://malariajournal.biomedcentral.com/track/pdf/10.1186/s12936-016-1498-9?site=malariajournal.biomedcentral.com
https://vlibrary.iwmi.org/pdf/H047719.pdf
https://vlibrary.iwmi.org/pdf/H047719.pdf
(1.39 MB)
Background: Sub-Saharan Africa (SSA) has embarked on a new era of dam building to improve food security and promote economic development. Nonetheless, the future impacts of dams on malaria transmission are poorly understood and seldom investigated in the context of climate and demographic change.
Methods: The distribution of malaria in the vicinity of 1268 existing dams in SSA was mapped under the Intergovernmental Panel on Climate Change (IPCC) representative concentration pathways (RCP) 2.6 and 8.5. Population projections and malaria incidence estimates were used to compute population at risk of malaria in both RCPs. Assuming no change in socio-economic interventions that may mitigate impacts, the change in malaria stability and malaria burden in the vicinity of the dams was calculated for the two RCPs through to the 2080s. Results were compared against the 2010 baseline. The annual number of malaria cases associated with dams and climate change was determined for each of the RCPs.
Results: The number of dams located in malarious areas is projected to increase in both RCPs. Population growth will add to the risk of transmission. The population at risk of malaria around existing dams and associated reservoirs, is estimated to increase from 15 million in 2010 to 21–23 million in the 2020s, 25–26 million in the 2050s and 28–29 million in the 2080s, depending on RCP. The number of malaria cases associated with dams in malarious areas is expected to increase from 1.1 million in 2010 to 1.2–1.6 million in the 2020s, 2.1–3.0 million in the 2050s and 2.4–3.0 million in the 2080s depending on RCP. The number of cases will always be higher in RCP 8.5 than RCP 2.6.
Conclusion: In the absence of changes in other factors that affect transmission (e.g., socio-economic), the impact of dams on malaria in SSA will be significantly exacerbated by climate change and increases in population. Areas without malaria transmission at present, which will transition to regions of unstable transmission, may be worst affected. Modifying conventional water management frameworks to improve malaria control, holds the potential to mitigate some of this increase and should be more actively implemented.
Methods: The distribution of malaria in the vicinity of 1268 existing dams in SSA was mapped under the Intergovernmental Panel on Climate Change (IPCC) representative concentration pathways (RCP) 2.6 and 8.5. Population projections and malaria incidence estimates were used to compute population at risk of malaria in both RCPs. Assuming no change in socio-economic interventions that may mitigate impacts, the change in malaria stability and malaria burden in the vicinity of the dams was calculated for the two RCPs through to the 2080s. Results were compared against the 2010 baseline. The annual number of malaria cases associated with dams and climate change was determined for each of the RCPs.
Results: The number of dams located in malarious areas is projected to increase in both RCPs. Population growth will add to the risk of transmission. The population at risk of malaria around existing dams and associated reservoirs, is estimated to increase from 15 million in 2010 to 21–23 million in the 2020s, 25–26 million in the 2050s and 28–29 million in the 2080s, depending on RCP. The number of malaria cases associated with dams in malarious areas is expected to increase from 1.1 million in 2010 to 1.2–1.6 million in the 2020s, 2.1–3.0 million in the 2050s and 2.4–3.0 million in the 2080s depending on RCP. The number of cases will always be higher in RCP 8.5 than RCP 2.6.
Conclusion: In the absence of changes in other factors that affect transmission (e.g., socio-economic), the impact of dams on malaria in SSA will be significantly exacerbated by climate change and increases in population. Areas without malaria transmission at present, which will transition to regions of unstable transmission, may be worst affected. Modifying conventional water management frameworks to improve malaria control, holds the potential to mitigate some of this increase and should be more actively implemented.
12 Chapungu, L.; Nhamo, Luxon. 2016. An assessment of the impact of climate change on plant species richness through an analysis of the normalised difference water index (NDWI) in Mutirikwi Sub-catchment, Zimbabwe. South African Journal of Geomatics, 5(2):244-268.
Climate change ; Plants ; Species ; Biodiversity ; Catchment areas ; Rainfall patterns ; Temperature ; Meteorological stations ; Remote sensing ; Vegetative period ; Environmental impact ; Satellite imagery / Zimbabwe / Mutirikwi Sub-catchment
(Location: IWMI HQ Call no: e-copy only Record No: H047746)
This study assesses the effects of climate change on vegetative species diversity exploring the usefulness of the Normalised Difference Water Index (NDWI) in predicting spatio-temporal diversity variations. The relationship between species richness and climatic variables of rainfall and temperature is explored based on species data collected from the field over a 3 year period and climate data collected from four local weather stations. Relationship between NDWI and species diversity indices is examined to confirm the usefulness of Remote Sensing in predicting vegetative diversity. The resultant predictive model was used to estimate changes in species richness over a 27 year period (1987-2014). The species diversity data was then regressed with climatic data for the same period. The results show a significant (P<0.05) correlation between species diversity and the two climatic variables. The results also indicate that there is a significant positive (P=0.0001; a=0.05; R2=0.565) relationship between species richness and NDWI. This implies that the NDWI is essential when assessing changes in species diversity over time. The Mann Kendall test revealed a decrease, though not statistically significant, in the rainfall received within the catchment over the period and significant variability. The minimum and maximum temperatures over the period were significantly increasing. These changes in climate variables were matched with a decrease in species richness. Some species tend to be succumbing to the environmental changes influenced by climate change resulting in their changes in phenology, abundance and distribution.
13 Nhamo, Luxon; Mabhaudhi, T.; Magombeyi, Manuel. 2016. Improving water sustainability and food security through increased crop water productivity in Malawi. Water, 8(9):1-12. [doi: https://doi.org/10.3390/w8090411]
Food security ; Water management ; Water productivity ; Water scarcity ; Water use ; Freshwater ; Crop production ; Sustainability ; Agricultural production ; Evapotranspiration ; Population growth ; Urbanization ; Maize ; Rainfed farming ; Irrigation systems ; Smallholders / Malawi
(Location: IWMI HQ Call no: e-copy only Record No: H047747)
(1.48 MB)
Agriculture accounts for most of the renewable freshwater resource withdrawals in Malawi, yet food insecurity and water scarcity remain as major challenges. Despite Malawi’s vast water resources, climate change, coupled with increasing population and urbanisation are contributing to increasing water scarcity. Improving crop water productivity has been identified as a possible solution to water and food insecurity, by producing more food with less water, that is, to produce “more crop per drop”. This study evaluated crop water productivity from 2000 to 2013 by assessing crop evapotranspiration, crop production and agricultural gross domestic product (Ag GDP) contribution for Malawi. Improvements in crop water productivity were evidenced through improved crop production and productivity. These improvements were supported by increased irrigated area, along with improved agronomic practices. Crop water productivity increased by 33% overall from 2000 to 2013, resulting in an increase in maize production from 1.2 million metric tons to 3.6 million metric tons, translating to an average food surplus of 1.1 million metric tons. These developments have contributed to sustainable improved food and nutrition security in Malawi, which also avails more water for ecosystem functions and other competing economic sectors.
14 Mabhaudhi, T.; Mpandeli, S.; Chimonyo, V. G. P.; Nhamo, Luxon; Backeberg, G.; Modi, A. T. 2016. Prospects for improving irrigated agriculture in southern Africa – linking water, energy and food. Paper presented at the 2nd World Irrigation Forum, Chiang Mai, Thailand, 6-8 November 2016. 10p.
Farming systems ; Small scale farming ; Irrigated farming ; Agriculture ; Rainfed farming ; Cultivated land ; Food security ; Food insecurity ; Food production ; Water productivity ; Water scarcity ; Water use efficiency ; Nutritional losses ; Energy demand ; Energy consumption ; Infrastructure ; Dam construction ; Smallholders ; Farmers ; Capacity building / Southern Africa / Africa South of Sahara
(Location: IWMI HQ Call no: e-copy only Record No: H047846)
(0.63 MB)
Sub-Saharan Africa (SSA) faces high incidence of food and nutrition insecurity. Consequently, increasing agricultural productivity has always featured prominently on regional agenda. The Comprehensive Africa Agriculture Development Programme’s (CAADP) set a target to expand the area under irrigation by at least 5 million ha by 2025. This review assessed the current status of irrigated agriculture in SSA from a water–energy–food nexus perspective, focusing on southern Africa. Gaps and opportunities for improving irrigated agriculture were also assessed in terms of the feasible limits to which they can be exploited. Sub-Saharan Africa faces water scarcity and projections show that countries in SSA will face increased physical and / or economic water scarcity by 2025. However, with agriculture already accounting for more than 60% of water withdrawals, increasing area under irrigation could worsen the problem of water scarcity. Recurrent droughts experienced across SSA reaffirm the sensitive issue of food insecurity and water scarcity. The region also faces energy insecurity with most countries experiencing chronic power outages. Increasing area under irrigation will place additional demand on the already strained energy grids. Projections of an increasing population within SSA indicate increased food and energy demand; a growing middle class also adds to increasing food demand. This poses the question - is increasing irrigated agriculture a solution to water scarcity, food insecurity and energy shortages? This review recommends that, whilst there are prospects for increasing area under irrigation and subsequent agricultural productivity, technical planning should adopt a water–energy–food nexus approach to setting targets. Improving water productivity in irrigated agriculture could reduce water and energy use while increasing yield output.
15 Cai, Xueliang; Haile, Alemseged Tamiru; Magidi, J.; Mapedza, Everisto; Nhamo, Luxon. 2017. Living with floods – household perception and satellite observations in the Barotse floodplain, Zambia. Physics and Chemistry of the Earth, 100:278-286. [doi: https://doi.org/10.1016/j.pce.2016.10.011]
Natural disasters ; Floodplains ; Hydrology ; Indigenous knowledge ; Remote sensing ; Risk prevention ; Households ; Living standards ; Satellite observation ; Satellite imagery ; Farmland / Zambia / Barotseland
(Location: IWMI HQ Call no: e-copy only Record No: H047877)
The Barotse Floodplain, a designated Ramsar site, is home to thousands of indigenous people along with an extensive wetland ecosystem and food production system. Increasingly it is also a popular tourist destination with its annual Kuomboka festival which celebrates the relocation of the king and the Lozi people to higher ground before the onset of the ood season. This paper presents an integrated approach which cross validates and combines the oodplain residents' perceptions about recent oods with information on ood inundation levels derived from satellite observations. Local residents' surveys were conducted to assess farmers’ perception on the ooding patterns and the impact on their livelihoods. Further, a series of ood inundation maps from 1989 to 2014 generated from remotely sensed Landsat imagery were used to assess the recent patterns of oods. Results show that the oodplain has a population of 33 thousand living in 10,849 small permeant or temporary buildings with a total cropland area of 4976 ha. The oodplain hydrologyand ooding patterns have changed, con rmed by both surveys and satellite image analysis, due to catchment development and changing climate. The average annual inundated areas have increased from about 316 thousand ha in 1989e1998 to 488 thousand ha in 2005 e2014. As a result the inundated cropland and houses increased from 9% to 6% in 1989 to 73% and 47% in 2014, respectively. The timing of the oods has also changed with both delaying and early onset happening more frequently. These changes cause increasing dif culties in ood forecast and preparation using indigenous knowledge, therefore creating greater damages to crops, livestock, and houses. Current oodplain management system is inadequate and new interventions are needed to help manage the oods at a systematic manner.
16 Cai, Xueliang; Magidi, J.; Nhamo, Luxon; van Koppen, Barbara. 2017. Mapping irrigated areas in the Limpopo Province, South Africa. Colombo, Sri Lanka: International Water Management Institute (IWMI). 37p. (IWMI Working Paper 172) [doi: https://doi.org/10.5337/2017.205]
Irrigated land ; Agricultural land ; Cultivated land ; Agricultural development ; Rainfed farming ; Land cover ; Remote sensing ; Satellite imagery ; Mapping ; Sustainable development ; Water resources ; Water security ; Surface water ; Groundwater irrigation ; Seasonal cropping ; Winter crops ; Food production ; Developing countries ; Irrigation operation ; Smallholders ; Surveys ; Capacity building / South Africa / Limpopo Province
(Location: IWMI HQ Call no: IWMI Record No: H048084)
(2 MB)
This report summarizes the findings of a collaborative effort to map and assess irrigated areas in the Limpopo Province, South Africa. The study was conducted by the International Water Management Institute (IWMI) in collaboration with the Department of Agriculture, Forestry and Fisheries (DAFF) and the Limpopo Department of Agriculture and Rural Development (LDARD), as part of the DAFF-supported ‘Revitalization of irrigation in South Africa’ project. Based on a combination of Landsat and Moderate Resolution Imaging Spectroradiometer (MODIS) satellite data, previous irrigated area mapping exercises carried out by DAFF and three-field ground truthing (GT) surveys, a total of 1.6 million hectares (Mha) of cropland were identified, with 262,000 ha actually irrigated in the 2015 winter season. The study also found that only 29% of all land equipped with center pivots was actually irrigated.
17 van Koppen, Barbara; Nhamo, Luxon; Cai, Xueliang; Gabriel, M. J.; Sekgala, M.; Shikwambana, S.; Tshikolomo, K.; Nevhutanda, S.; Matlala, B.; Manyama, D. 2017. Smallholder irrigation schemes in the Limpopo Province, South Africa. Colombo, Sri Lanka: International Water Management Institute (IWMI). 36p. (IWMI Working Paper 174) [doi: https://doi.org/10.5337/2017.206]
Irrigation schemes ; Small scale systems ; Smallholders ; Social aspects ; Gender ; Water resources ; Water quality ; Infrastructure ; Rehabilitation ; Seasonal cropping ; Farmland ; Marketing ; Poverty ; Irrigated land ; Land tenure ; Land ownership ; Soils ; Vegetables ; Farmers ; Utilization ; State intervention / South Africa / Limpopo Province
(Location: IWMI HQ Call no: IWMI Record No: H048142)
(2 MB)
A survey of 76 public smallholder irrigation schemes in the Limpopo Province was jointly conducted by the International Water Management Institute (IWMI), Department of Agriculture, Forestry and Fisheries (DAFF), South Africa, and the Limpopo Department of Agriculture and Rural Development (LDARD), as part of the ‘Revitalization of Smallholder Irrigation in South Africa’ project. About one-third of those schemes was fully utilized; one-third partially utilized; and one-third not utilized in the winter of 2015; however, no single socioeconomic, physical, agronomic and marketing variable could explain these differences in utilization. Sale, mostly for informal markets, appeared the most important goal. Dilapidated infrastructure was the most important constraint cited by the farmers. The study recommends ways to overcome the build-neglect-rebuild syndrome, and to learn lessons from informal irrigation, which covers an area three to four times as large as public irrigation schemes in the province.
18 Saruchera, D.; Lautze, Jonathan; Nhamo, Luxon; Holmatov, B. 2017. Water security. In Lautze, Jonathan; Phiri, Z.; Smakhtin, Vladimir; Saruchera, D. (Eds.). 2017. The Zambezi River Basin: water and sustainable development. Oxon, UK: Routledge - Earthscan. pp.215-233. (Earthscan Series on Major River Basins of the World)
Water security ; Water supply ; Water use ; Water requirements ; Sanitation ; Investment ; River basin management ; Environmental flows ; Agriculture ; Energy resources / Angola / Tanzania / Mozambique / Zambezi River Basin
(Location: IWMI HQ Call no: IWMI Record No: H048280)
19 Dickens, Chris; Rebelo, Lisa-Maria; Nhamo, Luxon. 2017. Guidelines and indicators for Target 6.6 of the SDGs: “change in the extent of water-related ecosystems over time” Colombo, Sri Lanka: International Water Management Institute (IWMI). CGIAR Research Program on Water, Land and Ecosystems (WLE) 56p.
Sustainable development ; Ecosystem services ; Guidelines ; Indicators ; Monitoring ; Marshes ; Swamps ; Wetlands ; Forests ; Paddy fields ; Peatlands ; Mangroves ; Lakes ; Ponds ; Rivers ; Groundwater ; Earth observation satellites ; Remote sensing ; Water quality ; Flow discharge ; Stream flow ; Reservoirs ; Environmental health
(Location: IWMI HQ Call no: e-copy only Record No: H048340)
20 Nhamo, Luxon; Magidi, J.; Dickens, Chris. 2017. Determining wetland spatial extent and seasonal variations of the inundated area using multispectral remote sensing. Water SA, 43(4):543-552. [doi: https://doi.org/10.4314/wsa.v43i4.02]
Wetlands ; Flooding ; Remote sensing ; GIS ; Spatial planning ; Multispectral imagery ; Satellite imagery ; Sustainable development ; Ecosystems ; Dam construction ; Catchment areas / South Africa / Mpumalanga Province / Witbank Dam
(Location: IWMI HQ Call no: e-copy only Record No: H048390)
https://www.ajol.info/index.php/wsa/article/download/162560/152061
https://vlibrary.iwmi.org/pdf/H048390.pdf
https://vlibrary.iwmi.org/pdf/H048390.pdf
(2.58 MB)
Wetlands can only be well managed if their spatial location and extent are accurately documented, which presents a problem as wetland type and morphology are highly variable. Current efforts to delineate wetland extent are varied, resulting in a host of inconsistent and incomparable inventories. This study, done in the Witbank Dam Catchment in Mpumalanga Province of South Africa, explores a remote-sensing technique to delineate wetland extent and assesses the seasonal variations of the inundated area. The objective was to monitor the spatio-temporal changes of wetlands over time through remote sensing and GIS for effective wetland management. Multispectral satellite images, together with a digital elevation model (DEM), were used to delineate wetland extent. The seasonal variations of the inundated area were assessed through an analysis of monthly water indices derived from the normalised difference water index (NDWI). Landsat images and DEM were used to delineate wetland extent and MODIS images were used to assess seasonal variation of the inundated area. A time-series trend analysis on the delineated wetlands shows a declining tendency from 2000 to 2015, which could worsen in the coming few years if no remedial action is taken. Wetland area declined by 19% in the study area over the period under review. An analysis of NDWI indices on the wetland area showed that wetland inundated area is highly variable, exhibiting an increasing variability over time. An overlay of wetland area on cultivated land showed that 21% of the wetland area is subjected to cultivation which is a major contributing factor to wetland degradation.
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