Your search found 40 records
1 Kibret, S.; Lautze, Jonathan; McCartney, Matthew; Nhamo, Luxon; Yan, G. 2019. Malaria around large dams in Africa: effect of environmental and transmission endemicity factors. Malaria Journal, 18:1-12. [doi: https://doi.org/10.1186/s12936-019-2933-5]
Malaria ; Vector-borne diseases ; Dams ; Environmental effects ; Disease transmission ; Endemics ; Mosquitoes ; Anopheles ; Breeding habitats ; Water reservoirs ; Slope ; Topography ; Climatic data ; Communities ; Health hazards / Africa South of Sahara
(Location: IWMI HQ Call no: e-copy only Record No: H049330)
https://malariajournal.biomedcentral.com/track/pdf/10.1186/s12936-019-2933-5
https://vlibrary.iwmi.org/pdf/H049330.pdf
https://vlibrary.iwmi.org/pdf/H049330.pdf
(3.62 MB) (3.62 MB)
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 (< 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 < 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.
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 (< 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 < 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.
2 Zeitoun, M.; Dajani, M.; Abdallah, C.; Khresat, S.; Elaydi, H. 2019. The Yarmouk Tributary to the Jordan River II: infrastructure impeding the transformation of equitable transboundary water arrangements. Water Alternatives, 12(3):1095-1122.
International waters ; International agreements ; Treaties ; River basins ; Infrastructure ; Weirs ; Dams ; Water reservoirs ; International cooperation ; Water use ; Political aspects / Jordan / Israel / Syrian Arab Republic / Yarmouk River Basin / Jordan River Basin / Adassiyeh Weir / Wehdeh Dam
(Location: IWMI HQ Call no: e-copy only Record No: H049354)
http://www.water-alternatives.org/index.php/alldoc/articles/volume-12/v12issue3/556-a12-3-12/file
https://vlibrary.iwmi.org/pdf/H049354.pdf
https://vlibrary.iwmi.org/pdf/H049354.pdf
(2.09 MB) (2.09 MB)
This article explores the ways in which key components of infrastructure built on the Yarmouk tributary to the Jordan River induce or impede the transformation of existing transboundary water arrangements. Focussing on the Jordanian-Israeli Adassiyeh Weir and on the Jordanian-Syrian Wehdeh Dam, the article interprets archival documents, official river-gauging data, and interviews through a frame that highlights depoliticisation by hydrocracies within the politics of international infrastructure. The weir is found to be operated in a manner that prioritises Jordan's commitment to Israel when flows are low, and to be designed to bound the volume that Jordan can make use of during low or very high flows. The dam appears oversized but regulates the flow to the downstream weir when its reservoir does not lie empty. The design and operation of the infrastructure is found to partially and selectively depoliticise contentious transboundary water issues in a manner that privileges the more powerful actors. Transformation of the arrangements is impeded as the distribution and use of the flows is not questioned by the water authorities or the international diplomatic community, and alternative arrangements are not considered.
3 Ahmadianfar, I.; Zamani, R. 2020. Assessment of the hedging policy on reservoir operation for future drought conditions under climate change. Climatic Change, 159(2):253-268. [doi: https://doi.org/10.1007/s10584-020-02672-y]
Water reservoirs ; Reservoir operation ; Climate change ; Policies ; Drought ; Forecasting ; Agricultural water use ; Water requirements ; Water resources ; Rain ; Water demand ; Sustainability ; Models ; Performance evaluation / Iran Islamic Republic / Jarreh Reservoir
(Location: IWMI HQ Call no: e-copy only Record No: H049557)
(1.05 MB)
Reservoirs play a fundamental role in enhancing sustainable development and economic circumstances, especially in areas with limited water resources. Recently, experts in water resources management have been faced with global warming and climate change as two critical issues that are causing serious problems in water resources. Accordingly, the current study attempts to evaluate the future climate change impacts on agricultural reservoir operation. The results indicated an increase in mean long-term temperature, decreased reservoir’s inflow, and an increase in the agricultural water requirement for the Jarreh reservoir system in southwestern Iran, during the period of 2025–2054, under the RCP 8.5 scenario. The results also showed a decrease in reliability (37%) and an increase in vulnerability (9%) using standard operation policy (SOP) under future climate conditions. Due to the predicted drought conditions for the study area, a two-dimensional hedging policy is proposed to mitigate the negative effects of climate change. The results of the hedging model indicated an improvement in the performance of indices in comparison with the use of SOP under climate change impacts. Generally, by using the hedging policy, decreased vulnerability (24%) and reduced maximum deficiencies (14%) are expected for future climate changes.
4 Alimohammadi, H.; Bavani, A. R. M.; Roozbahani, A. 2020. Mitigating the impacts of climate change on the performance of multi-purpose reservoirs by changing the operation policy from SOP [Standard Operating Policy] to MLDR [Modified Linear Decision Rule]. Water Resources Management, 22p. (Online first) [doi: https://doi.org/10.1007/s11269-020-02516-5]
Climate change mitigation ; Water reservoirs ; Reservoir operation ; Reservoir storage ; Water resources ; Dams ; Policies ; Runoff ; Water demand ; Sustainability ; Models ; Performance indexes ; Case studies / Iran Islamic Republic / Karaj Dam
(Location: IWMI HQ Call no: e-copy only Record No: H049577)
(2.03 MB)
In many parts of the world, especially in metropolitan areas with dry climates, shortages of freshwater resources have become a significant challenge in water resources management. Rapid population growth and climate change in these areas impose additional burdens on water consumption, especially on surface water resources, which are increasingly becoming scarce. In this study, a change from the Standard Operating Policy (SOP) to the Modified Linear Decision Rule (MLDR) policy is considered as a solution to mitigate the impacts of climate change on dams and reservoir operation. The two policies were compared by using five reservoir system performance indices (reliability, resiliency, vulnerability, sustainability and meeting demands) and three hydropower energy generation indices. This study pertained to the Karaj hydropower dam reservoir in Iran and speculated on 2020–2039. Changing the operation policy from current SOP to the MLDR policy can mitigate the adverse effects brought by climate change. According to the results, the SOP policy works best for reservoir operation if there is enough water (optimistic scenario). In the case of pessimistic scenarios (shortage of water), operating the reservoir system with SOP policy would turn into a crisis in supplying drinking water. On the other hand, the MLDR policy prevents the complete draining of the reservoir. In all water-demand scenarios, the MLDR policy reduces the amount of time (by over 90%) in which the reservoir remains empty, compared to the SOP policy. The final results demonstrate how the MLDR policy can mitigate the undesirable effects of climate change.
5 Zavalloni, M.; Raggi, M.; Viaggi, D. 2020. Irrigation reservoirs as blue clubs: governance and policy intervention. Water Resources and Economics, 29:100142. [doi: https://doi.org/10.1016/j.wre.2019.03.002]
Irrigation water ; Water reservoirs ; Water governance ; Policies ; Collective action ; Farmers ; Water use ; Groundwater management ; Water availability ; Models
(Location: IWMI HQ Call no: e-copy only Record No: H049640)
https://www.sciencedirect.com/science/article/pii/S221242841830032X/pdfft?md5=64c1cb1f458e93b00b098994c6fd443e&pid=1-s2.0-S221242841830032X-main.pdf
https://vlibrary.iwmi.org/pdf/H049640.pdf
https://vlibrary.iwmi.org/pdf/H049640.pdf
(1.27 MB) (1.27 MB)
6 Nurhusein, M. M. 2020. Water consumption by hydropower, does it worth allocation under Ethiopian context. Journal of Water Resource and Protection, 12(3):183-202. [doi: https://doi.org/10.4236/jwarp.2020.123012]
Hydropower ; Water use ; Water allocation ; Water reservoirs ; Development projects ; Hydroelectric power generation ; Water policy ; Evaporation ; Estimation / Ethiopia
(Location: IWMI HQ Call no: e-copy only Record No: H049691)
(0.56 MB) (576 KB)
The Ethiopian water policy strictly follows water allocation as a principle in setting out water consumption problems and demand projection. Hydroelectric power plants supply the larger share (88%) of the electricity in Ethiopia. 86% of Ethiopia’s plan to 2020 energy supply is expected to be from hydropower. This paper defines water consumption in hydropower production as the quantity of water that leaves the analyzed projects (reservoir regulated hydropower projects) through evaporation. Water consumed by hydropower development has never been studied at a country scale. Thus, in attempting to understand water consumption by the hydropower development, this study will be the first to acknowledge the water consumption by all storage regulated hydropower plants developed in Ethiopia. While studying and designing reservoir regulated hydropower production, the overall effect of water consumption by the projects is assumed to be minimal; thus ignoring water allocation to hydropower projects is a common procedure in Ethiopia. In this study, for multipurpose projects, to identify the water consumption by hydropower against the other purpose (irrigation) consumption, water consumption factors based on economic benefits were used. The study has shown that the 14 existing and under construction reservoir regulated hydropower projects will consume 1.881 billion m3 of water annually. This will make hydropower the second most water consuming water resource development next to Irrigation in the country. Together with the 22 upcoming projects the water consumption will be 3.756 billion m3/year. The results also show that hydropower consumption in the country will take an average of 2.41% of the total water stored in a reservoir. This value is in the range of nearly zero for power projects that use natural lakes as their reservoir (Tana Beles, Tis Abay I & II) and GERD to 10.64%. The total reservoir volume that will be created in the country after completion of the 22 planned projects is larger than 233 BCM, which is greater than the surface water volume the country possesses. This indicates that the future water consumption by hydropower plants shall be revised in accordance with changes made in the final design of each planned projects. Nonetheless, this research provides scientific support for the argument that the production of hydroelectricity by reservoir regulated hydropower schemes, in countries like Ethiopia, is a water consumer. Thus, water allocation shall not ignore its demand.
7 Wu, P.-Y.; You, G. J.-Y.; Chan, M.-H. 2020. Drought analysis framework based on copula and poisson process with nonstationarity. Journal of Hydrology, 588:125022. (Online first) [doi: https://doi.org/10.1016/j.jhydrol.2020.125022]
Drought ; Water resources ; Water reservoirs ; Watersheds ; Stream flow ; Water supply ; Meteorological factors ; Hydrology ; Precipitation ; Models ; Case studies / Taiwan / Zengwen Reservoir / Shihmen Reservoir
(Location: IWMI HQ Call no: IWMI HQ Record No: H049757)
(2.50 MB)
Droughts have been occurring with increased frequency and bringing with them considerable losses. Due to its nature, the best approach to monitoring and assessing droughts is in terms of stochastic theories. As a consequence, this study applied SPI in the hydrological drought detection, and examine/interpret drought-related phenomena. The 3-month SPI is used to decide the drought development and terminate phases based on the coincidence of hydrological drought and anomalies in precipitation.
Four primary characteristics were determined to clarify the descriptions of drought magnitude and occurrence: duration, deficit, occurrence time and recurrence year. A stochastic process of drought is established to take account these characteristics using the copula function and a Poisson process as well as non-stationarity. Case study on the Shihmen and Zengwen reservoir watersheds in Taiwan revealed that hydrological drought events often coincide with meteorological drought, but some inconsistencies due to unusual hydrological hysteresis in rainfall and runoff. Our analysis raised several issues, including the choice of drought identification parameters and SPI time scale/ threshold, which should take into account anthropogenic activity and hydrological characteristics. A positive correlation between drought duration and drought deficit and a negative correlation between them and occurrence time were identified. It was also observed that subsequent drought event may be more severe due to the partial recovery of hydrological condition. In terms of non-stationarity, our results do not show strong evidence of long-term trend for drought characteristics. Some limitations could be due to the percentile-to-percentile basis of copula. This issue may need to be examined using non-stationary copula analysis or time-variant correlation-covariance models. In the end, we demonstrated that this framework can apply in forecasting drought conditions and generating synthetic droughts for use in the formulation of water resources management strategies and the development of drought preparedness plans.
Four primary characteristics were determined to clarify the descriptions of drought magnitude and occurrence: duration, deficit, occurrence time and recurrence year. A stochastic process of drought is established to take account these characteristics using the copula function and a Poisson process as well as non-stationarity. Case study on the Shihmen and Zengwen reservoir watersheds in Taiwan revealed that hydrological drought events often coincide with meteorological drought, but some inconsistencies due to unusual hydrological hysteresis in rainfall and runoff. Our analysis raised several issues, including the choice of drought identification parameters and SPI time scale/ threshold, which should take into account anthropogenic activity and hydrological characteristics. A positive correlation between drought duration and drought deficit and a negative correlation between them and occurrence time were identified. It was also observed that subsequent drought event may be more severe due to the partial recovery of hydrological condition. In terms of non-stationarity, our results do not show strong evidence of long-term trend for drought characteristics. Some limitations could be due to the percentile-to-percentile basis of copula. This issue may need to be examined using non-stationary copula analysis or time-variant correlation-covariance models. In the end, we demonstrated that this framework can apply in forecasting drought conditions and generating synthetic droughts for use in the formulation of water resources management strategies and the development of drought preparedness plans.
8 Cecchi, P.; Forkuor, G.; Cofie, Olufunke; Lalanne, F.; Poussin, J.-C.; Jamin, J.-Y. 2020. Small reservoirs, landscape changes and water quality in Sub-Saharan West Africa. Water, 12(7):1967. [doi: https://doi.org/10.3390/w12071967]
Water reservoirs ; Water quality ; Land use change ; Land cover change ; Anthropogenic factors ; Watersheds ; Landsat ; Satellite imagery ; Farmland ; Vegetation ; Lakes ; Dry season ; Population density ; Indicators / Africa South of Sahara / West Africa / Burkina Faso
(Location: IWMI HQ Call no: e-copy only Record No: H049806)
(2.94 MB) (2.94 MB)
Small reservoirs (SRs) are essential water storage infrastructures for rural populations of Sub-Saharan West Africa. In recent years, rapid population increase has resulted in unprecedented land use and land cover (LULC) changes. Our study documents the impacts of such changes on the water quality of SRs in Burkina Faso. Multi-temporal Landsat images were analyzed to determine LULC evolutions at various scales between 2002 and 2014. Population densities were calculated from downloaded 2014 population data. In situ water samples collected in 2004/5 and 2014 from selected SRs were analyzed for Suspended Particulate Matter (SPM) loads, an integrative proxy for water quality. The expansion of crop and artificial areas at the expense of natural covers controlled LULC changes over the period. We found a very significant correlation between SPM loads and population densities calculated at a watershed scale. A general increase between the two sampling dates in the inorganic component of SPM loads, concomitant with a clear expansion of cropland areas at a local scale, was evidenced. Results of the study suggest that two complementary but independent indicators (i.e., LULC changes within 5-km buffer areas around SRs and demographic changes at watershed scale), relevantly reflected the nature and intensity of overall pressures exerted by humans on their environment, and locally on aquatic ecosystems. Recommendations related to the re-greening of peripheral areas around SRs in order to protect water bodies are suggested.
9 Annys, S.; Van Passel, S.; Dessein, J.; Ghebreyohannes, T.; Adgo, E.; Nyssen, J. 2020. Small-scale irrigation expansion along the dam-regulated Tekeze River in northern Ethiopia. International Journal of Water Resources Development, 23p. (Online first) [doi: https://doi.org/10.1080/07900627.2020.1808446]
Farmer managed irrigation systems ; Small scale systems ; River regulation ; Dams ; Water reservoirs ; Hydropower ; Irrigated farming ; Farming systems ; Farmland ; Land tenure ; Policies ; Markets ; Models / Ethiopia / Tekeze River
(Location: IWMI HQ Call no: e-copy only Record No: H049983)
(9.58 MB)
Based on extensive field information, farmer-led small-scale irrigation systems along the dam-regulated Tekeze River is investigated and the likelihood of future irrigation expansion within the area with modelled potential is discussed, considering facilitating and hampering factors. Due to dam-induced hydrologic alterations, downstream socio-ecological systems have strongly transformed as the irrigated area has quadrupled and the post-dam potential for perennial crop cultivation has attracted numerous migrant investors to the area, inducing inequalities but also providing opportunities. Future dam construction should involve tailored policy interventions to facilitate irrigation expansion, while safeguarding equal and sustainable access to water and land.
10 Nguyen-Khoa, S.; McCartney, Matthew; Funge-Smith, S.; Smith, L.; Senaratna Sellamuttu, Sonali; Dubois, M. 2020. Increasing the benefits and sustainability of irrigation through the integration of fisheries: a guide for water planners, managers and engineers. Rome, Italy: FAO; Penang, Malaysia: WorldFish; Colombo, Sri Lanka: International Water Management Institute (IWMI). 92p. [doi: https://doi.org/10.4060/cb2025en]
Fishery production ; Sustainability ; Irrigation systems ; Integrated management ; Water resources ; Water management ; Guidelines ; Irrigation management ; Aquatic ecosystems ; Habitats ; Aquaculture ; Irrigated farming ; Infrastructure ; Livelihoods ; Food security ; Nutrition security ; Socioeconomic environment ; Monitoring and evaluation ; Environmental Impact Assessment ; Trends ; Sustainable Development Goals ; Community management ; Participatory approaches ; Water governance ; Institutions ; Stakeholders ; Conflicts ; Rural areas ; Water reservoirs ; Rivers ; Floodplains / Africa / Asia
(Location: IWMI HQ Call no: e-copy only Record No: H050111)
(2.84 MB)
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.
11 Cooley, S. W.; Ryan, J. C.; Smith, L. C. 2021. Human alteration of global surface water storage variability. Nature, 591(7848):78-81. [doi: https://doi.org/10.1038/s41586-021-03262-3]
Surface water ; Water storage ; Water resources ; Water management ; Water levels ; Lakes ; River basins ; Water reservoirs ; Dams ; Satellite observation ; Uncertainty
(Location: IWMI HQ Call no: e-copy only Record No: H050280)
(5.76 MB)
Knowing the extent of human influence on the global hydrological cycle is essential for the sustainability of freshwater resources on Earth1,2. However, a lack of water level observations for the world’s ponds, lakes and reservoirs has limited the quantification of human-managed (reservoir) changes in surface water storage compared to its natural variability3. The global storage variability in surface water bodies and the extent to which it is altered by humans therefore remain unknown. Here we show that 57 per cent of the Earth’s seasonal surface water storage variability occurs in human-managed reservoirs. Using measurements from NASA’s ICESat-2 satellite laser altimeter, which was launched in late 2018, we assemble an extensive global water level dataset that quantifies water level variability for 227,386 water bodies from October 2018 to July 2020. We find that seasonal variability in human-managed reservoirs averages 0.86 metres, whereas natural water bodies vary by only 0.22 metres. Natural variability in surface water storage is greatest in tropical basins, whereas human-managed variability is greatest in the Middle East, southern Africa and the western USA. Strong regional patterns are also found, with human influence driving 67 per cent of surface water storage variability south of 45 degrees north and nearly 100 per cent in certain arid and semi-arid regions. As economic development, population growth and climate change continue to pressure global water resources4, our approach provides a useful baseline from which ICESat-2 and future satellite missions will be able to track human modifications to the global hydrologic cycle.
12 Housh, M.; Aharon, T. 2021. Info-gap models for optimal multi-year management of regional water resources systems under uncertainty. Sustainability, 13(6):3152. (Special issue: Sustainable Water Resource Management in a Changing Climate) [doi: https://doi.org/10.3390/su13063152]
Water resources ; Water management ; Water supply ; Uncertainty ; Climate change ; Water reservoirs ; Watersheds ; Surface water ; Decision making ; Sensitivity analysis ; Policies ; Case studies ; Hydrology ; Models / Israel / Sea of Galilee
(Location: IWMI HQ Call no: e-copy only Record No: H050309)
(3.02 MB) (3.02 MB)
The common practices for the planning and management of Water Resources Systems (WSSs) have been challenged in the last few decades by global climate change processes, which are observed around the world in increasing frequencies. Climate change is manifested by climate variability, temperature increase, and extreme events such as droughts and floods, which have a decisive effect on natural resource availability and in turn on water quality. Historical records may not be sufficient to reliably account for uncertain future predictions under climate change conditions. While such highly uncertain situations become the “normal” case worldwide, the traditional practices of probabilistic risk measures cannot be used to appropriately quantify the uncertain phenomena under non-stationarity conditions. To better account for uncertain future conditions, the objective of this study is to develop a water management model based on Info-Gap Decision Theory (IGDT) using optimization under deep uncertainty conditions. The Info-Gap theory is a framework that measures the confidence in the operational decisions by quantifying the robustness to uncertainty without accounting for any probabilistic data. To demonstrate the method as a tool to better guide the long-term sustainable operation of the water supply system under uncertain future conditions, we applied the Info-Gap model to the Sea of Galilee (SoG) regional WSS, which is a significant part of the Israeli National Water System (INWS). For Israel, which is, like other Middle East semi-arid regions, prone to dry conditions and limited water availability, there are well-founded concerns that prolonged periods of drought lie ahead, as a consequence of the global climate change processes. This study contributes a management tool for decision making under deep uncertainty to improve the decision-making process and better adapt to unpredictable uncertain future conditions. We demonstrate how the IGDT could be formulated and used to analyze WSSs under different settings and demonstrate how decisions could be derived from the IGDT formulation. We also show a sensitivity analysis for the obtained solutions.
13 Kibret, S.; McCartney, Matthew; Lautze, Jonathan; Nhamo, Luxon; Yan, G. 2021. The impact of large and small dams on malaria transmission in four basins in Africa. Scientific Reports, 11:13355. [doi: https://doi.org/10.1038/s41598-021-92924-3]
Malaria ; Disease transmission ; Dams ; River basins ; Vector-borne diseases ; Risk ; Water reservoirs ; Infrastructure ; Population density / Africa South of Sahara / Limpopo River Basin / Omo-Turkana River Basin / Volta River Basin / Zambezi River Basin
(Location: IWMI HQ Call no: e-copy only Record No: H050499)
(1.51 MB) (1.51 MB)
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 (< 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.
14 Guan, T.; Xu, Q.; Chen, X.; Cai, J. 2021. A novel remote sensing method to determine reservoir characteristic curves using high-resolution data. Hydrology Research, 52(5):1066-1082. [doi: https://doi.org/10.2166/nh.2021.035]
Water reservoirs ; Water levels ; Surface water ; Remote sensing ; Satellite imagery ; Landsat ; Datasets / China / Zhejiang / Jinshuitan Reservoir / Shitang Reservoir / Ou River Basin
(Location: IWMI HQ Call no: e-copy only Record No: H050701)
https://iwaponline.com/hr/article-pdf/52/5/1066/950733/nh0521066.pdf
https://vlibrary.iwmi.org/pdf/H050701.pdf
https://vlibrary.iwmi.org/pdf/H050701.pdf
(1.20 MB) (1.20 MB)
A novel method of determining reservoir characteristic curves based on high-resolution resource satellite data was proposed in this paper, using remote sensing processing and analysis technology. According to the physical characteristics of absorption, radiation and reflection of surface water on ultraviolet, visible, near-infrared bands, etc., the satellite images at different reservoir water level and different periods were processed to analyze the relationship of measured water level corresponding to the water area. Based on the relationship, the relevance among reservoir water level, water surface area, and reservoir capacity was established, so as to determine the reservoir characteristic curve. The method was applied and validated at Jinshuitan Reservoir and Shitang Reservoir in the Ou River Basin. The results show that this method has high accuracy, and the maximum relative error between calculating values and measured values at different water level are -2.33% and -2.11% in Jinshuitan Reservoir and Shitang Reservoir, respectively. The method improves the convenience of determining the reservoir characteristic curve greatly, and the storage capacity of the reservoir can be calculated rapidly by this method.
15 Elsayed, H.; Djordjevic, S.; Savic, D.; Tsoukalas, I.; Makropoulos, C. 2022. Water-food-energy nexus for transboundary cooperation in eastern Africa. Water Supply, 21p. (Online first) [doi: https://doi.org/10.2166/ws.2022.001]
International waters ; Water resources ; Food production ; Energy ; Nexus ; International cooperation ; River basins ; Dams ; Water reservoirs ; Water management ; Water demand ; Water shortage ; Water policies ; Water allocation ; Water governance ; Hydroelectric power generation ; Modelling / East Africa / Ethiopia / Sudan / Egypt / Nile River Basin / Grand Ethiopian Renaissance Dam
(Location: IWMI HQ Call no: e-copy only Record No: H050861)
https://iwaponline.com/ws/article-pdf/doi/10.2166/ws.2022.001/999156/ws2022001.pdf
https://vlibrary.iwmi.org/pdf/H050861.pdf
https://vlibrary.iwmi.org/pdf/H050861.pdf
(1.11 MB) (1.11 MB)
Establishing cooperation in transboundary rivers is challenging especially with the weak or non-existent river basin institutions. A nexus-based approach is developed to explore cooperation opportunities in transboundary river basins while considering system operation and coordination under uncertain hydrologic river regimes. The proposed approach is applied to the Nile river basin with a special focus on the Grand Ethiopian Renaissance Dam (GERD), assuming two possible governance positions: with or without cooperation. A cooperation mechanism is developed to allocate additional releases from the GERD when necessary, while a unilateral position assumes that the GERD is operated to maximize hydropower generation regardless of downstream users' needs. The GERD operation modes were analysed considering operation of downstream reservoirs and varying demands in Egypt. Results show that average basin-wide hydropower generation is likely to increase by about 547 GWh/year (1%) if cooperation is adopted when compared to the unilateral position. In Sudan, hydropower generation and water supply are expected to enhance in the unilateral position and would improve further with cooperation. Furthermore, elevated low flows by the GERD are likely to improve the WFE nexus outcomes in Egypt under full cooperation governance scenario with a small reduction in GERD hydropower generation (2,000 GWh/year (19%)).
16 Eriyagama, Nishadi; Smakhtin, V.; Udamulla, L. 2022. Sustainable surface water storage development: measuring economic benefits and ecological and social impacts of reservoir system configurations. Water, 14(3):307. (Special issue: Relationship of Energy and Water Resource Availability) [doi: https://doi.org/10.3390/w14030307]
Surface water ; Water storage ; Economic benefits ; Ecological factors ; Social impact ; Water reservoirs ; River basins ; Sustainability ; Equity / Sri Lanka / Malwatu Oya Basin / Kalu Ganga Basin
(Location: IWMI HQ Call no: e-copy only Record No: H050900)
(5.43 MB) (5.43 MB)
This paper illustrates an approach to measuring economic benefits and ecological and social impacts of various configurations of reservoir systems for basin-wide planning. It suggests indicators and examines their behavior under several reservoir arrangement scenarios using two river basins in Sri Lanka as examples. A river regulation index is modified to take into account the volume of flow captured by reservoirs and their placement and type. Indices of connectivity illustrate that the lowest river connectivity in a basin results from a single new reservoir placed on the main stem of a previously unregulated river between the two locations that command 50% and 75% of the basin area. The ratio of the total affected population to the total number of beneficiaries is shown to increase as the cumulative reservoir capacity in a river basin increases. An integrated index comparing the performance of different reservoir system configurations shows that while results differ from basin to basin, the cumulative effects of a large number of small reservoirs may be comparable to those with a few large reservoirs, especially at higher storage capacities.
17 Kumar, S.; Machiwal, D.; Tetarwal, A. S.; Ramniwas; Vaishnav, M. 2022. Managing irrigation supplies effectively under interrupted electricity supply: lesson from an arid region of India. Agricultural Water Management, 263:107465. (Online first) [doi: https://doi.org/10.1016/j.agwat.2022.107465]
Electricity supplies ; Groundwater irrigation ; Irrigation water ; Arid zones ; Irrigation systems ; Groundwater extraction ; Tube wells ; Pumps ; Water reservoirs ; Water levels ; Irrigated farming ; Surface water ; Water storage ; Groundwater table ; Indigenous knowledge ; Evaporation ; Models / India / Gujarat / Kachchh / Sanyra
(Location: IWMI HQ Call no: e-copy only Record No: H050890)
(5.30 MB)
Groundwater extraction through electrically operated tubewells offers a resilient source of irrigation supply in arid regions especially during droughts. However, interrupted and low-voltage electric supply with limited availability and frequent trips increases repair and maintenance costs of tubewell irrigation and reduces tubewell discharge resulting in less-efficient and non-uniform water application. This study evaluates performance of an indigenous system of groundwater irrigation that was evolved over the generations in arid region of Gujarat, India to address electricity-triggered issues of irrigated agriculture. In this system, groundwater extracted during electricity availability hours is stored in surface reservoirs for later supplying to irrigate crops under gravity flow irrespective of electricity availability. A comprehensive survey of the indigenous system is conducted in a village of Gujarat to make inventory of all tubewells and storage reservoirs about their depth, size, pump type and horsepower, command area, crops, irrigation timing and frequency, etc. Discharge of tubewells was measured and their locations were recorded. Results revealed that the indigenous system is advantageous over the direct tubewell-irrigation in terms of 37.4% higher water-delivery rate and 50% more average irrigation capacity. These findings prove adequacy of the indigenous system in regulating irrigation supplies to deal with electricity-induced intricacies of irrigated agriculture. Amount of water lost through unit area of earthen (seepage and evaporation ~2.77 m) and masonry (evaporation ~1.22 m) reservoirs collectively accounts for a negligible proportion (0.9%) of groundwater draft. Furthermore, a methodology is devised to precisely estimate village-level groundwater draft for irrigation, which is validated by 0.9% deviation between observed and predicted values of groundwater draft. Moreover, the indigenous system is simple, cost-effective and easy to implement in other parts of the world especially in arid regions of the developing countries where low-voltage and intermitted electricity supply persists.
18 Ficklin, D. L.; Null, S. E.; Abatzoglou, J. T.; Novick, K. A.; Myers, D. T. 2022. Hydrological intensification will increase the complexity of water resource management. Earth’s Future, 10(3):e2021EF002487. [doi: https://doi.org/10.1029/2021EF002487]
Water resources ; Water management ; Hydrological cycle ; Intensification ; Climate change ; Forecasting ; Precipitation ; Evapotranspiration ; Infrastructure ; Water reservoirs ; River basins ; Drought ; Flooding ; Soil moisture ; Vegetation ; Models
(Location: IWMI HQ Call no: e-copy only Record No: H051012)
https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/2021EF002487
https://vlibrary.iwmi.org/pdf/H051012.pdf
https://vlibrary.iwmi.org/pdf/H051012.pdf
(1.90 MB) (1.90 MB)
Global warming intensifies the hydrological cycle by altering the rate of water fluxes to and from the terrestrial surface, resulting in an increase in extreme precipitation events and longer dry spells. Prior hydrological intensification work has largely focused on precipitation without joint consideration of evaporative demand changes and how plants respond to these changes. Informed by state-of-the-art climate models, we examine projected changes in hydrological intensification and its role in complicating water resources management using a framework that accounts for precipitation surplus and evaporative demand. Using a metric that combines the difference between daily precipitation and daily evaporative demand (surplus events) and consecutive days when evaporative demand exceeds precipitation (deficit time), we show that, globally, surplus events will become larger (+11.5% and +18.5% for moderate and high emission scenarios, respectively) and the duration between them longer (+5.1%; +9.6%) by the end of the century, with the largest changes in the northern latitudes. The intra-annual occurrence of these extremes will stress existing water management infrastructure in major river basins, where over one third of years during 2070–2100 under a moderate emissions scenario will be hydrologically intense (large intra-annual increases in surplus intensity and deficit time), tripling that of the historical baseline. Larger increases in hydrologically intense years are found in basins with large reservoir capacity (e.g., Amazon, Congo, and Danube River Basins), which have significant populations, irrigate considerable farmland, and support threatened and endangered aquatic species. Incorporating flexibility into water resource infrastructure and management will be paramount with continued hydrological intensification.
19 Wable, P. S.; Garg, K. K.; Nune, R; Venkataradha, A.; Anantha, K. H.; Srinivasan, V.; Ragab, R.; Rowan, J.; Keller, V.; Majumdar, P.; Rees, G.; Singh, R.; Dixit, S. 2022. Impact of agricultural water management interventions on upstream-downstream trade-offs in the Upper Cauvery Catchment, southern India: a modelling study. Irrigation and Drainage, 71(2):472-494. [doi: https://doi.org/10.1002/ird.2662]
Agriculture ; Water management ; Catchment areas ; Upstream ; Downstream ; Water balance ; Water reservoirs ; Runoff ; Land use ; Land cover ; Groundwater ; Water storage ; Rain ; Models / India / Karnataka / Upper Cauvery Catchment
(Location: IWMI HQ Call no: e-copy only Record No: H051055)
(89.40 MB)
The Cauvery basin in southern India is experiencing transboundary issues due to increasing water demand. This study analysed water balance components and the impact of agricultural water management (AWM) interventions in the upper Cauvery catchment of the Cauvery basin. Results showed that the study catchment receives an average of 1280 mm of annual rainfall. Of this, 29% (370 mm) flows downstream, 54% (700 mm) contributes to evapotranspiration (ET) and 17% (215 mm) contributes to groundwater recharge and surface storage. Rainfall varies from 700 to 5400 mm and the Western Ghats (mountain pass) are the main source of freshwater generation. The estimated ET in different catchments ranged from 500 to 900 mm per annum. An increase in the allocation of fresh water supplied by all three reservoirs (Hemavathi, Harangi and KRS) was observed in the canal command areas, from 1450 million cubic metres (MCM) yr ¹ in 1971–1980 to 3800 MCM yr ¹ in 2001–2010. AWM interventions harvested 140–160 MCM (13–20 mm) of surface runoff upstream of the upper Cauvery and reduced inflow into the Krishnaraja Sagar reservoir by 2–6%. The study findings are useful for designing and planning suitable water management interventions at basin scale.
20 Jayawardena, I. M. S. P.; Punyawardena, B. V. R.; Karunarathne, M. D. R. K. 2022. Importance of integration of subseasonal predictions to improve climate services in Sri Lanka case study: southwest monsoon 2019. Climate Services, 26:100296. [doi: https://doi.org/10.1016/j.cliser.2022.100296]
Climate services ; Forecasting ; Monsoons ; Case studies ; Rain ; Precipitation ; Water reservoirs ; Hydroelectric power generation ; Decision making / Sri Lanka
(Location: IWMI HQ Call no: e-copy only Record No: H051064)
https://www.sciencedirect.com/science/article/pii/S2405880722000140/pdfft?md5=ef9c00f2a20476f596bd3405d25519b7&pid=1-s2.0-S2405880722000140-main.pdf
https://vlibrary.iwmi.org/pdf/H051064.pdf
https://vlibrary.iwmi.org/pdf/H051064.pdf
(7.53 MB) (7.53 MB)
The climate outlook for the 2019 southwest monsoon (SWM) season was prepared through an expert assessment of the prevailing global climate conditions and forecasts from different climate models from around the world during the fourteenth session of the South Asian Climate Outlook Forum (SASCOF14). Above-normal rainfall was predicted over Sri Lanka for SWM 2019, and information was shared at the monsoon forum. Even though SWM 2019 seasonal rainfall wasslightly above average, highly uneven rainfall distribution with a deficit of rainfall at the beginning and a surplus of rainfall during the latter part of the season was observed. Unusual dry conditioned prevailed during the month of May 2019, which led to delay the onset of SWM by 2 weeks. Due to the delay of onset and rainfall deficit during the early part of 2019 SWM, late cultivation of paddy was observed. Hydro-catchment areas recorded large shortfalls in early part Southwest Monsoon rainfall reducing hydropower generation to 15–18%, from May to July.
The suppressed phase of Madden Julian Oscillation (MJO) (phase 6 to 8) with anomalous easterly winds over Sri Lanka was evident from 04th May to 25th May. As MJO being a major predictive source in subseasonal timescale and Sri Lanka being a country located in the heart of the MJO envelope, integration of subseasonal information into seasonal outlook provide much greater value to decision-makers in Agriculture and Energy sector.
The suppressed phase of Madden Julian Oscillation (MJO) (phase 6 to 8) with anomalous easterly winds over Sri Lanka was evident from 04th May to 25th May. As MJO being a major predictive source in subseasonal timescale and Sri Lanka being a country located in the heart of the MJO envelope, integration of subseasonal information into seasonal outlook provide much greater value to decision-makers in Agriculture and Energy sector.
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