Your search found 19 records
1 Yitayew, M.; Melesse, A. M. 2011. Critical water resources issues in the Nile River Basin. In Melesse, A. M. (Ed.). Nile River Basin: hydrology, climate and water use. Dordrecht, Netherlands: Springer. pp.401-416.
Water management ; River basins ; Geography ; Climate change ; Lakes ; Hydrology ; Hydroclimatology ; Political aspects / Africa / Ethiopia / Nile River Basin
(Location: IWMI HQ Call no: 551.483 G136 MEL Record No: H044040)
2 Yitayew, M. 2008. Critical water resources management issues in the Nile River Basin. In Abtew, W.; Melesse, A. M. (Eds.). Proceedings of the Workshop on Hydrology and Ecology of the Nile River Basin under Extreme Conditions, Addis Ababa, Ethiopia, 16-19 June 2008. Sandy, UT, USA: Aardvark Global Publishing. pp.295-309.
Water management ; Water resources ; River basins ; Hydroclimatology ; Political aspects ; Climate change / Ethiopia / Nile River Basin
(Location: IWMI HQ Call no: 551.48 G136 ABT Record No: H044331)
(1.01 MB)
3 Jaramillo, F.; Destouni, G. 2015. Local flow regulation and irrigation raise global human water consumption and footprint. Science, 350(6265):1248-1251. [doi: https://doi.org/10.1126/science.aad1010]
Water use ; Water footprint ; Freshwater ; Runoff ; Irrigation ; Evapotranspiration ; Hydroclimatology ; Catchment areas
(Location: IWMI HQ Call no: e-copy only Record No: H047405)
(0.89 MB)
Flow regulation and irrigation alter local freshwater conditions, but their global effects are highly uncertain. We investigated these global effects from 1901 to 2008, using hydroclimatic observations in 100 large hydrological basins. Globally, we find consistent and dominant effects of increasing relative evapotranspiration from both activities, and decreasing temporal runoff variability from flow regulation. The evapotranspiration effect increases the long-term average human consumption of fresh water by 3563 ± 979 km3/ year from 1901–1954 to 1955–2008. This increase raises a recent estimate of the current global water footprint of humanity by around 18%, to 10,688 ± 979 km3/year. The results highlight the global impact of local water-use activities and call for their relevant account in Earth system modeling.
4 Nanteza, J.; de Linage, C. R.; Thomas, B. F.; Famiglietti, J. S. 2016. Monitoring groundwater storage changes in complex basement aquifers: an evaluation of the GRACE satellites over East Africa. Water Resources Research, 52(12):9542-9564. [doi: https://doi.org/10.1002/2016WR018846.]
Groundwater ; Water storage ; Monitoring ; Aquifers ; Satellite observation ; Surface water ; Soil moisture ; Water balance ; Models ; Lakes ; Wells ; Water use ; Hydroclimatology ; Climate change ; Precipitation ; Rain ; Estimation / East Africa / Kenya / Uganda / Tanzania / Burundi / Rwanda / Upper Nile Basin / Lake Victoria / Lake Tanganyika / Lake Malawi / Lake Turkana / Lake Albert / Lake Mweru / Lake Edward
(Location: IWMI HQ Call no: e-copy only Record No: H048049)
(3.24 MB)
Although the use of the Gravity Recovery and Climate Experiment (GRACE) satellites to monitor groundwater storage changes has become commonplace, our evaluation suggests that careful processing of the GRACE data is necessary to extract a representative signal especially in regions with significant surface water storage (i.e., lakes/reservoirs). In our study, we use cautiously processed data sets, including GRACE, lake altimetry, and model soil moisture, to reduce scaling factor bias and compare GRACE-derived groundwater storage changes to in situ groundwater observations over parts of East Africa. Over the period 2007–2010, a strong correlation between in situ groundwater storage changes and GRACE groundwater estimates (Spearman's = 0.6) is found. Piecewise trend analyses for the GRACE groundwater estimates reveal significant negative storage changes that are attributed to groundwater use and climate variability. Further analysis comparing groundwater and satellite precipitation data sets permits identification of regional groundwater characterization. For example, our results identify potentially permeable and/or shallow groundwater systems underlying Tanzania and deep and/or less permeable groundwater systems underlying the Upper Nile basin. Regional groundwater behaviors in the semiarid regions of Northern Kenya are attributed to hydraulic connections to recharge zones outside the subbasin boundary. Our results prove the utility of applying GRACE in monitoring groundwater resources in hydrologically complex regions that are undersampled and where policies limit data accessibility.
5 Khan, H. F.; Morzuch, B. J.; Brown, C. M. 2017. Water and growth: an econometric analysis of climate and policy impacts. Water Resources Research, 53(6):5124-5136. [doi: https://doi.org/10.1002/2016WR020054]
Water stress ; Economic growth ; Climate change ; Policy making ; Econometrics ; Regression analysis ; Models ; Intensive farming ; Hydroclimatology ; Weather hazards ; Precipitation ; Temperature ; River basins ; Surface runoff
(Location: IWMI HQ Call no: e-copy only Record No: H048200)
(1.76 MB)
Water-related hazards such as floods, droughts, and disease cause damage to an economy through the destruction of physical capital including property and infrastructure, the loss of human capital, and the interruption of economic activities, like trade and education. The question for policy makers is whether the impacts of water-related risk accrue to manifest as a drag on economic growth at a scale suggesting policy intervention. In this study, the average drag on economic growth from water-related hazards faced by society at a global level is estimated. We use panel regressions with various specifications to investigate the relationship between economic growth and hydroclimatic variables at the country-river basin level. In doing so, we make use of surface water runoff variables never used before. The analysis of the climate variables shows that water availability and water hazards have significant effects on economic growth, providing further evidence beyond earlier studies finding that precipitation extremes were at least as important or likely more important than temperature effects. We then incorporate a broad set of variables representing the areas of infrastructure, institutions, and information to identify the characteristics of a region that determine its vulnerability to water-related risks. The results identify water scarcity, governance, and agricultural intensity as the most relevant measures affecting vulnerabilities to climate variability effects.
6 Moalafhi, D. B.; Sharma, A.; Evans, J. P. 2017. Reconstructing hydro-climatological data using dynamical downscaling of reanalysis products in data-sparse regions - application to the Limpopo Catchment in southern Africa. Journal of Hydrology: Regional Studies, 12:378-395. [doi: https://doi.org/10.1016/j.ejrh.2017.07.001]
Hydroclimatology ; Climatic data ; Models ; Simulation ; Meteorological observations ; Precipitation ; Temperature ; Arid climate ; Catchment areas ; River basins / Southern Africa / Limpopo Basin
(Location: IWMI HQ Call no: e-copy only Record No: H048295)
http://www.sciencedirect.com/science/article/pii/S2214581817302537/pdfft?md5=b8200e131bda5cfd71db88e4288c6253&pid=1-s2.0-S2214581817302537-main.pdf
https://vlibrary.iwmi.org/pdf/H048295.pdf
https://vlibrary.iwmi.org/pdf/H048295.pdf
(2.28 MB) (2.28 MB)
This study is conducted over the data-poor Limpopo basin centered over southern Africa using reanalysis downscaled to useful resolution.
Reanalysis products are of limited value in hydrological applications due to the coarse spatial scales they are available at. Dynamical downscaling of these products over a domain of interest offers a means to convert them to finer spatial scales in a dynamically consistent manner. Additionally, this downscaling also offers a way to resolve dominantatmospheric processes, leading to improved accuracy in the atmospheric variables derived. This study thus evaluates high-resolution downscaling of an objectively chosen reanalysis (ERA-I) over the Limpopo basin using Weather Research and Forecasting (WRF) as a regional climate model.
The model generally under-estimates temperature and over-estimates precipitation over the basin, although reasonably consistent with observations. The model does well in simulating observed sustained hydrological extremes as assessed using the Standardized Precipitation Index (SPI) although it consistently under-estimates the severity ofmoisture deficit for the wettest part of the year during the dry years. The basin's aridity index (I) is above the severe drought threshold during summer and is more severe in autumn. This practically restricts rain-fed agriculture to around 3 months in a year over the basin. This study presents possible beneficial use of the downscaled simulations foroptimal hydrologic design and water resources planning in data scarce parts of the world.
Reanalysis products are of limited value in hydrological applications due to the coarse spatial scales they are available at. Dynamical downscaling of these products over a domain of interest offers a means to convert them to finer spatial scales in a dynamically consistent manner. Additionally, this downscaling also offers a way to resolve dominantatmospheric processes, leading to improved accuracy in the atmospheric variables derived. This study thus evaluates high-resolution downscaling of an objectively chosen reanalysis (ERA-I) over the Limpopo basin using Weather Research and Forecasting (WRF) as a regional climate model.
The model generally under-estimates temperature and over-estimates precipitation over the basin, although reasonably consistent with observations. The model does well in simulating observed sustained hydrological extremes as assessed using the Standardized Precipitation Index (SPI) although it consistently under-estimates the severity ofmoisture deficit for the wettest part of the year during the dry years. The basin's aridity index (I) is above the severe drought threshold during summer and is more severe in autumn. This practically restricts rain-fed agriculture to around 3 months in a year over the basin. This study presents possible beneficial use of the downscaled simulations foroptimal hydrologic design and water resources planning in data scarce parts of the world.
7 Nasr-Azadani, F.; Khan, R.; Rahimikollu, J.; Unnikrishnan, A.; Akanda, A.; Alam, M.; Huq, A.; Jutla, A.; Colwell, R. 2017. Hydroclimatic sustainability assessment of changing climate on cholera in the Ganges-Brahmaputra Basin. Advances in Water Resources, 108:332-344. [doi: https://doi.org/10.1016/j.advwatres.2016.11.018]
Climate change ; Hydroclimatology ; Sustainability ; Assessment ; Health hazards ; Infectious diseases ; Cholera ; Stream flow ; Flow discharge ; Forecasting ; River basins ; Models / Bangladesh / Ganges Basin / Brahmaputra Basin / Meghna Basin / Bengal Delta
(Location: IWMI HQ Call no: e-copy only Record No: H048327)
(4.30 MB)
The association of cholera and climate has been extensively documented. However, determining the effects of changing climate on the occurrence of disease remains a challenge. Bimodal peaks of cholera in Bengal Delta are hypothesized to be linked to asymmetric flow of the Ganges and Brahmaputra rivers. Spring cholera is related to intrusion of bacteria-laden coastal seawater during low flow seasons, while autumn cholera results from cross-contamination of water resources when high flows in the rivers cause massive inundation. Coarse resolution of General Circulation Model (GCM) output (usually at 100 – 300 km)cannot be used to evaluate variability at the local scale(10–20 km),hence the goal of this study was to develop a framework that could be used to understand impacts of climate change on occurrence of cholera. Instead of a traditional approach of downscaling precipitation, streamflow of the two rivers was directly linked to GCM outputs, achieving reasonable accuracy (R2 = 0.89 for the Ganges and R2 = 0.91 for the Brahmaputra)using machine learning algorithms (Support Vector Regression-Particle Swarm Optimization). Copula methods were used to determine probabilistic risks of cholera under several discharge conditions. Key results, using model outputs from ECHAM5, GFDL, andHadCM3for A1B and A2 scenarios, suggest that the combined low flow of the two rivers may increase in the future, with high flows increasing for first half of this century, decreasing thereafter. Spring and autumn cholera, assuming societal conditions remain constant e.g., at the current rate, may decrease. However significant shifts were noted in the magnitude of river discharge suggesting that cholera dynamics of the delta may well demonstrate an uncertain predictable pattern of occurrence over the next century.
8 Ghale, Y. A. G.; Baykara, M.; Unal, A. 2019. Investigating the interaction between agricultural lands and Urmia Lake ecosystem using remote sensing techniques and hydro-climatic data analysis. Agricultural Water Management, 221:566-579. [doi: https://doi.org/10.1016/j.agwat.2019.05.028]
Farmland ; Lakes ; Ecosystems ; Agricultural development ; Water management ; Hydroclimatology ; Remote sensing ; Techniques ; Landsat ; Satellite imagery ; Soil salinity ; Desertification ; Land cover change ; Irrigated land ; Anthropogenic factors ; Climatic factors / Iran / Urmia Lake
(Location: IWMI HQ Call no: e-copy only Record No: H049260)
(6.51 MB)
Urmia Lake (UL) located in the northwest of Iran, is one of the largest hypersaline lakes in the world. In recent years, most of the lake has been rendered to unusable lands. Drought and rapid increase in agricultural activities are the most important reasons behind the shrinkage of the lake. In this study, hydro-climatic data, Landsat satellite images and image processing techniques were used to detect the spatio-temporal land cover changes and salinization progress in Urmia Lake Basin (ULB) between 1975 and 2019. Increasing the area of irrigated lands from 1265 km2 in 1975 to 5525 km2 in 2011 in contrast to decreasing the water surface area of UL from 5982 km2 in 1995 to 586 km2 in 2014 and extension of salinization in the basin are the most important and thoughtful results of this study. Even the agricultural lands in the regions close to the lake have been affected by this environmental problem. The climatic conditions have gradually improved after 2014 and the government has released more water from dams to the lake. On the other hand, the area of irrigated lands has gradually decreased by 12% in the same period. As a result of these positive changes, the water surface area of the lake has gradually increased over 1000 km2. Based on the results of this study, both anthropogenic and climatic factors have played a positive role in UL restoration. Improvement of agricultural methods and providing a sustainable agricultural water management system under a changing climate can play the most effective role in the lake rehabilitation.
9 Walker, D.; Haile, Alemseged Tamiru; Gowing, J.; Forsythe, N.; Parkin, G. 2019. Guideline: selection, training and managing para-hydrologists. Oxford, UK: University of Oxford. REACH Programme. 31p. (REACH Working Paper 6)
Hydrologists ; Training ; Guidelines ; Capacity building ; Participatory approaches ; Rural communities ; Hydroclimatology ; Hydrometeorology ; Water security ; Water resources ; Groundwater management ; Land degradation ; Monitoring ; Equipment / Ethiopia / India
(Location: IWMI HQ Call no: e-copy only Record No: H049390)
https://reachwater.org.uk/wp-content/uploads/2019/06/2019_06_Walker-et-al_2nd-Working-paper.pdf
https://vlibrary.iwmi.org/pdf/H049390.pdf
https://vlibrary.iwmi.org/pdf/H049390.pdf
(4.83 MB) (4.83 MB)
10 Walker, D.; Haile, Alemseged Tamiru; Gowing, J.; Legesse, Y.; Gebrehawariat, G.; Hundie, H; Berhanu, D.; Parkin, G. 2019. Guideline: community-based hydroclimate monitoring. Planning, establishing and operating. Oxford, UK: University of Oxford. REACH Programme. 59p. (REACH Working Paper 5)
Hydroclimatology ; Monitoring ; Planning ; Community involvement ; Participatory approaches ; Hydrometeorology ; Water resources ; Water management ; Water security ; Groundwater table ; Water extraction ; Watersheds ; Rivers ; Wells ; Land degradation ; Rural communities ; Sustainable land management ; Living standards ; Stakeholders ; Training / Ethiopia
(Location: IWMI HQ Call no: e-copy only Record No: H049391)
https://reachwater.org.uk/wp-content/uploads/2019/05/2019_05_Walker-et-al_Working-paper3.pdf
https://vlibrary.iwmi.org/pdf/H049391.pdf
https://vlibrary.iwmi.org/pdf/H049391.pdf
(5.58 MB) (5.58 MB)
11 Schulte-Kellinghaus, Nikola. 2019. Flood-based farming systems and human-water dynamics in the Ayeyarwady Delta, Myanmar. Thesis submitted to the Department of Geography, University of Bonn, Germany, in partial fulfillment of the requirement for the Master of Science. 100p.
Farming systems ; Flooded rice ; Floodplains ; Deltas ; Climate change ; Extreme weather events ; Biodiversity ; Flooded land ; Land use ; Surface water ; Hydroclimatology ; Monsoon climate ; Rain ; Rivers ; Soils ; Salinity ; Crop yield ; Farmers ; Market access ; Socioeconomic environment ; Models ; Uncertainty / Myanmar / Ayeyarwady Delta / Ayeyarwady River
(Location: IWMI HQ Call no: e-copy only Record No: H049445)
(8.57 MB)
The flood-based farming systems in the Ayeyarwady Delta in Myanmar are changing. Change describes the modification of the flood pattern which is constituted by depth and duration of flooding and is the determining factor for rice cultivation. Flood-induced crop loss poses the major challenge to the farmers in the delta. To understand the flood-based farming systems in the Ayeyarwady Delta, the random forest algorithm was applied to generate rice suitability location models and to create suitability maps. Thus, correlations were observed between the developed definitions for the three rice growing areas based on quantitative interviews with farmers and the physical factors obtained from the input datasets – mainly remote sensing data concerning surface water and vegetation. To underpin the information of the generated suitability maps, human-water dynamics in the Ayeyarwady Delta are exemplified in terms of the pluralistic water research (PWR) framework (EVERS ET AL. 2017). Socio-economic and hydro-climatic drivers control this system and besides determine the suitable location of the three rice growing areas. This concept facilitates an understanding of the relationships and feedbacks of the human-water dynamics and is able to analyse flood risk mitigation in the Ayeyarwady Delta.
12 Pavelic, Paul; Hoanh, Chu Thai; Viossanges, Mathieu; Vinh, B. N.; Chung, D. T.; D’haeze, D.; Dat, L. Q.; Ross, A. 2019. Managed aquifer recharge for sustaining groundwater supplies for smallholder coffee production in the central highlands of Vietnam: report on pilot trial design and results from two hydrological years (May 2017 to April 2019). Contribution to WLE project - Sustainable Groundwater. Colombo, Sri Lanka: International Water Management Institute (IWMI). 68p.
Groundwater recharge ; Aquifers ; Sustainability ; Water supply ; Agricultural production ; Coffee industry ; Highlands ; Groundwater table ; Water quality ; Cost benefit analysis ; Smallholders ; Farmers' attitudes ; Hydroclimatology ; Rain ; Wells ; Monitoring ; Filtration ; Modelling / Vietnam
(Location: IWMI HQ Call no: e-copy only Record No: H049492)
(2.77 MB) (2.77 MB)
13 Hasan, E.; Tarhule, A. 2020. GRACE: Gravity Recovery and Climate Experiment long-term trend investigation over the Nile River Basin: spatial variability drivers. Journal of Hydrology, 586:124870. [doi: https://doi.org/10.1016/j.jhydrol.2020.124870]
River basins ; Climate change ; Water storage ; Hydroclimatology ; Anthropogenic changes ; Precipitation ; Runoff ; Soil moisture ; Population density ; Evapotranspiration ; Vegetation ; Water resources ; Models ; Case studies / Africa / Nile River Basin
(Location: IWMI HQ Call no: e-copy only Record No: H049830)
(11.30 MB)
GRACE (Gravity Recovery and Climate Experiment) long-term terrestrial water storage anomaly (TWSA) is attributed to the complex interaction of climatic, physical and anthropogenic drivers. This paper, therefore, explores how different hydroclimatic and anthropogenic processes interact and combine over “space” to produce the mass variations that GRACE-TWSA detects. Using the Nile River Basin (NRB) as a case study, it explicitly analyzes nine hydroclimatic and anthropogenic processes, as well as their relationship to the TWSA in different climatic zones. The analytic method employed the long-term trends derived for both the dependent (TWSA) and independent (explanatory) variables via applying two geographically multiple regression (GMR) approaches: (i) an ordinary least square regression (OLS) model in which the contributions of all variables to TWSA variability are deemed equal at all locations; and (ii) a geographically weighted regression (GWR) which assigns a weight to each variable at different locations based on clustering occurrences. The models’ efficacy was investigated using standard goodness of fit diagnostics. The OLS explains that the basin at large TWSA spatial variability significantly attributed to five variables, i.e., precipitation, runoff, surface water storage, soil moisture storage, and population density, (p < 0.0001). The OLS model, however, produced an R2 value of 0.14 with skewed standardized residuals. In contrast, the GWR model retained varying explanatory variables by different climate zone. For instance, the results showed that all nine variables contribute significantly, with varying ranking, to the trend in TWSA in the tropical zone. The evapotranspiration (ET) and population density are the only significant variables in the semiarid zone; population density contributes significantly to TWSA variability in all zones. The GWR model yielded R2 values with a median of 0.71 and normally distributed standard residuals. To evaluate the robustness of the GWR approach, the basin-wide TWSA pattern was simulated using the GWR model outputs. Herein, the GWR highlights the importance of the spatial locations to attribute the spatial variability in GRACE TSWA long-term trends. This spatial information, therefore, is critical for developing robust statistical models for reconstructing time series of proxy GRACE anomalies that predate the launch of the GRACE and for gap-filling between GRACE and GRACE Follow-On (GRACE-FO) mission.
14 Singh, R.; Pandey, Vishnu Prasad; Kayastha, S. P. 2021. Hydro-climatic extremes in the Himalayan watersheds: a case of the Marshyangdi Watershed, Nepal. Theoretical and Applied Climatology, 143(1-2):131-158. [doi: https://doi.org/10.1007/s00704-020-03401-2]
Watersheds ; Hydroclimatology ; Extreme weather events ; Temperature ; Precipitation ; Forecasting ; River basins ; Stream flow ; Climate change ; Spatial distribution ; Trends ; Models ; Hydrological factors ; Meteorological stations / Nepal / Himalayan Region / Marshyangdi Watershed
(Location: IWMI HQ Call no: e-copy only Record No: H050018)
(5.06 MB)
Climate change/variability and subsequent exacerbation of extremes are affecting human and ecological health across the globe. This study aims at unpacking hydro-climatic extremes in a snow-fed Marshyangdi watershed, which has a potential for water infrastructure development, located in Central Nepal. Bias-corrected projected future climate for near (2014–2033) and mid-future (2034–2053) under moderate and pessimistic scenarios were developed based on multiple regional climate models. Historical (1983–2013) and future trends of selected climatic extreme indices were calculated using RClimDex and hydrological extremes using Indicators of Hydrologic Alteration tool. Results show that historical trends in precipitation extremes such as number of heavy and very heavy precipitation days and maximum 1-day precipitation are decreasing while the temperature-related extremes have both increasing and decreasing trends (e.g., warm spell duration index, warm days and summer days are increasing whereas cold spell duration index, cool days and warm nights are decreasing). These results indicate drier and hotter conditions over the historical period. The projected future temperature indices (hot nights, warm days) reveal increasing trend for both the scenarios in contrast with decreasing trends in some of the extreme precipitation indices such as consecutive dry and wet days and maximum 5-day precipitation. Furthermore, the watershed has low mean hydrological alterations (27.9%) in the natural flow regime. These results indicate continuation of wetter and hotter future in the Marshyangdi watershed with likely impacts on future water availability and associated conflicts for water allocation, and therefore affect the river health conditions.
15 Taye, Meron Teferi; Haile, Alemseged Tamiru; Fekadu, A. G.; Nakawuka, P. 2021. Effect of irrigation water withdrawal on the hydrology of the Lake Tana sub-basin. Journal of Hydrology: Regional Studies, 38:100961. [doi: https://doi.org/10.1016/j.ejrh.2021.100961]
Irrigation water ; Water extraction ; Hydrology ; Irrigation schemes ; Small scale systems ; Water balance ; Dry season ; Water availability ; Water scarcity ; Irrigated land ; Hydroclimatology ; Crop production ; Water requirements ; Water use ; Rivers ; Smallholders ; Farmers / Ethiopia / Upper Blue Nile Basin / Lake Tana Sub-Basin
(Location: IWMI HQ Call no: e-copy only Record No: H050794)
https://www.sciencedirect.com/science/article/pii/S2214581821001907/pdfft?md5=7e540b0f0dc1c7747491b5c5fb401376&pid=1-s2.0-S2214581821001907-main.pdf
https://vlibrary.iwmi.org/pdf/H050794.pdf
https://vlibrary.iwmi.org/pdf/H050794.pdf
(7.37 MB) (7.37 MB)
Study region: The Lake Tana sub-basin, upper Blue Nile, Ethiopia.
Study focus: The Lake Tana sub-basin is one of the agricultural growth corridors for Ethiopia’s ambitious plan to expand irrigation. Despite the booming irrigation activities in the sub-basin, limited information exists on the rate of irrigation expansion and its impact on the water balance of the sub-basin. This study collected and organized smallholder irrigation data in the subbasin to identify the actual irrigated area, the abstracted irrigation water, and its implications on seasonal water availability. The area under small-scale irrigation was estimated through data obtained from ’woredas’ (districts) databases. Crop patterns were obtained through field surveys. Irrigation water abstracted at daily timescale was measured.
New hydrological insights for the Region: In the sub-basin, 38,694 ha was under small-scale irrigation in 2020/21. Surface water is the dominant water source, and it supplies about 80% of irrigation withdrawal. Water abstraction for small-scale irrigation is about 430 MCM per dry season (~50% of dry season flow). The eastern side of the sub-basin faces water shortages as the dry season flow is not sufficient for irrigation. With the prospects of more irrigation expansion, small-scale irrigation water withdrawals pose concerns of water scarcity at local level and to the water balance of the sub-basin. Hence, there is urgent need for adaptive management of the small-scale irrigation effect on the sub-basin’s hydrology.
Study focus: The Lake Tana sub-basin is one of the agricultural growth corridors for Ethiopia’s ambitious plan to expand irrigation. Despite the booming irrigation activities in the sub-basin, limited information exists on the rate of irrigation expansion and its impact on the water balance of the sub-basin. This study collected and organized smallholder irrigation data in the subbasin to identify the actual irrigated area, the abstracted irrigation water, and its implications on seasonal water availability. The area under small-scale irrigation was estimated through data obtained from ’woredas’ (districts) databases. Crop patterns were obtained through field surveys. Irrigation water abstracted at daily timescale was measured.
New hydrological insights for the Region: In the sub-basin, 38,694 ha was under small-scale irrigation in 2020/21. Surface water is the dominant water source, and it supplies about 80% of irrigation withdrawal. Water abstraction for small-scale irrigation is about 430 MCM per dry season (~50% of dry season flow). The eastern side of the sub-basin faces water shortages as the dry season flow is not sufficient for irrigation. With the prospects of more irrigation expansion, small-scale irrigation water withdrawals pose concerns of water scarcity at local level and to the water balance of the sub-basin. Hence, there is urgent need for adaptive management of the small-scale irrigation effect on the sub-basin’s hydrology.
16 Wang-Erlandsson, L.; Tobian, A.; van der Ent, R. J.; Fetzer, I.; te Wierik, S.; Porkka, M.; Staal, A.; Jaramillo, F.; Dahlmann, H.; Singh, C.; Greve, P.; Gerten, D.; Keys, P. W.; Gleeson, T.; Cornell, S. E.; Steffen, W.; Bai, X.; Rockstrom, J. 2022. A planetary boundary for green water. Nature Reviews Earth and Environment, 3(6):380-392. [doi: https://doi.org/10.1038/s43017-022-00287-8]
Freshwater ; Water availability ; Climate change ; Resilience ; Risk ; Soil moisture ; Precipitation ; Vegetation ; Evaporation ; Hydroclimatology ; Biogeochemical cycle ; Carbon cycle ; Ecosystems ; Governance ; Deforestation ; Drylands
(Location: IWMI HQ Call no: e-copy only Record No: H051114)
(1.67 MB)
Green water — terrestrial precipitation, evaporation and soil moisture — is fundamental to Earth system dynamics and is now extensively perturbed by human pressures at continental to planetary scales. However, green water lacks explicit consideration in the existing planetary boundaries framework that demarcates a global safe operating space for humanity. In this Perspective, we propose a green water planetary boundary and estimate its current status. The green water planetary boundary can be represented by the percentage of ice-free land area on which root-zone soil moisture deviates from Holocene variability for any month of the year. Provisional estimates of departures from Holocene-like conditions, alongside evidence of widespread deterioration in Earth system functioning, indicate that the green water planetary boundary is already transgressed. Moving forward, research needs to address and account for the role of root-zone soil moisture for Earth system resilience in view of ecohydrological, hydroclimatic and sociohydrological interactions.
17 Orr, A.; Ahmad, B.; Alam, U.; Appadurai, A. N.; Bharucha, Z. P.; Biemans, H.; Bolch, T.; Chaulagain, N. P.; Dhaubanjar, S.; Dimri, A. P.; Dixon, H.; Fowler, H. J.; Gioli, G.; Halvorson, S. J.; Hussain, A.; Jeelani, G.; Kamal, S.; Khalid, I. S.; Liu, S.; Lutz, A.; Mehra, M. K.; Miles, E.; Momblanch, A.; Muccione, V.; Mukherji, Aditi; Mustafa, D.; Najmuddin, O.; Nasimi, M. N.; Nusser, M.; Pandey, V. P.; Parveen, S.; Pellicciotti, F.; Pollino, C.; Potter, E.; Qazizada, M. R.; Ray, S.; Romshoo, S.; Sarkar, S. K.; Sawas, A.; Sen, S.; Shah, A.; Ali Shah, M. Azeem; Shea, J. M.; Sheikh, A. T.; Shrestha, A. B.; Tayal, S.; Tigala, S.; Virk, Z. T.; Wester, P.; Wescoat, J. L. Jr. 2022. Knowledge priorities on climate change and water in the Upper Indus Basin: a horizon scanning exercise to identify the top 100 research questions in social and natural sciences. Earth's Future, 10(4):e2021EF002619. [doi: https://doi.org/10.1029/2021EF002619]
Climate change adaptation ; Water resources ; Water management ; Water availability ; River basins ; Governance ; Policies ; Sustainability ; Livelihoods ; Vulnerability ; Poverty ; Socioeconomic aspects ; Gender ; Agriculture ; Natural disasters ; Hydroclimatology ; Ecosystems ; Glaciers ; Mountains / Pakistan / India / China / Afghanistan / Hindu-Kush Karakoram Himalaya Region / Upper Indus Basin
(Location: IWMI HQ Call no: e-copy only Record No: H051443)
https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/2021EF002619
https://vlibrary.iwmi.org/pdf/H051443.pdf
https://vlibrary.iwmi.org/pdf/H051443.pdf
(2.20 MB) (2.20 MB)
River systems originating from the Upper Indus Basin (UIB) are dominated by runoff from snow and glacier melt and summer monsoonal rainfall. These water resources are highly stressed as huge populations of people living in this region depend on them, including for agriculture, domestic use, and energy production. Projections suggest that the UIB region will be affected by considerable (yet poorly quantified) changes to the seasonality and composition of runoff in the future, which are likely to have considerable impacts on these supplies. Given how directly and indirectly communities and ecosystems are dependent on these resources and the growing pressure on them due to ever-increasing demands, the impacts of climate change pose considerable adaptation challenges. The strong linkages between hydroclimate, cryosphere, water resources, and human activities within the UIB suggest that a multi- and inter-disciplinary research approach integrating the social and natural/environmental sciences is critical for successful adaptation to ongoing and future hydrological and climate change. Here we use a horizon scanning technique to identify the Top 100 questions related to the most pressing knowledge gaps and research priorities in social and natural sciences on climate change and water in the UIB. These questions are on the margins of current thinking and investigation and are clustered into 14 themes, covering three overarching topics of “governance, policy, and sustainable solutions”, “socioeconomic processes and livelihoods”, and “integrated Earth System processes”. Raising awareness of these cutting-edge knowledge gaps and opportunities will hopefully encourage researchers, funding bodies, practitioners, and policy makers to address them.
18 Karesdotter, E.; Skoog, G.; Pan, H.; Kalantari, Z. 2023. Water-related conflict and cooperation events worldwide: a new dataset on historical and change trends with potential drivers. Science of The Total Environment, 868:161555. [doi: https://doi.org/10.1016/j.scitotenv.2023.161555]
Climate change ; Water security ; Drought ; Hydroclimatology ; Precipitation ; Evapotranspiration ; Conflicts ; Political aspects ; Freshwater
(Location: IWMI HQ Call no: e-copy only Record No: H051990)
https://www.sciencedirect.com/science/article/pii/S0048969723001705/pdfft?md5=b25774b3219af9ba9dbf8def7cfdd2bf&pid=1-s2.0-S0048969723001705-main.pdf
https://vlibrary.iwmi.org/pdf/H051990.pdf
https://vlibrary.iwmi.org/pdf/H051990.pdf
(2.44 MB) (2.44 MB)
Despite strong interest and conflict research spanning multiple disciplines, connections between water flows and conflicts remain unclear, due to incomplete datasets on water-related conflict-cooperation events and poor understanding of socioeconomic and biophysical causes of such conflicts. The dataset on water-related conflict-cooperation events compiled in this study extends to 2019, updating previous datasets that covered only up to 2008, yielding important new insights on cooperation-conflict trends. Global and regional trends were analyzed using the new events dataset, together with changes in hydroclimatic variables and population density. The analysis revealed that water-related cooperation was far more common than conflicts across all regions, in both drier and wetter climates, indicating that abundance and lack of water can both promote cooperation. However, conflict events were more common in drier climates where water is scarcer. This cooperation-conflict balance shifted in the 2000s, with conflict events increasing, to outnumber cooperation events in 2017. The main shift occurred in Africa and Asia, where increased conflicts in Africa coincided with a prolonged period of below-average precipitation and severe drought, while the shift in Asia coincided with increased evapotranspiration caused by human activities and increased population density. Differences between regions were confirmed by event descriptions, with events in Africa relating to water access and farmer-herder conflicts, and events in Asia relating to irrigation and dam construction. These differences highlight the need for regional-scale analysis of water-related conflict-cooperation trends and pathways. With climate change and human activities expected to increase, the increasing trend in conflict events could persist, with water resources becoming a more frequent cause of future conflict. Identifying these complex cooperation-conflict changes is vital in determining future actions required to reduce conflict events and promote cooperation on water.
19 Pokharel, P.; Regmi, R. K. 2024. Climate change and hydropower resilience in Nepal: an integrated modeling approach in the Madi River Basin. H2Open Journal, 7(2):199-221. [doi: https://doi.org/10.2166/h2oj.2024.110]
Climate change ; Hydropower ; Hydroelectric power generation ; Resilience ; Models ; Hydroclimatology ; Stream flow ; Energy security ; Renewable energy ; Precipitation ; Water management / Nepal / Madi River Basin
(Location: IWMI HQ Call no: e-copy only Record No: H052760)
https://iwaponline.com/h2open/article-pdf/7/2/199/1396837/h2oj0070199.pdf
https://vlibrary.iwmi.org/pdf/H052760.pdf
https://vlibrary.iwmi.org/pdf/H052760.pdf
(1.41 MB) (1.41 MB)
Responding to Nepal's hydropower sector's vulnerability to climate change, this study investigates its impact on energy security, focusing on the Madi River Basin's river systems. This study conducted a rigorous analysis of the basin's historical and future hydroclimatic trends, using the linear scaling method to correct inherent biases in 13 GCMs, resulting in the selection of 6 BCMs with above-satisfactory performance. Future projections reveal an increase in annual precipitation with a higher increment in SSP585 by the end of the century, and a temperature rise ranging from 1.8 to 3.5 °C from the baseline in the far future under moderate- to high-emission scenarios. These hydroclimatic projections are then forced into the calibrated soil and water assessment tool (SWAT) model with very good performance (both R2 and NSE greater than 0.8). The streamflow projection demonstrates an overall increasing trend, marked by significant flow reduction in early months and pronounced monsoon peaks. The analysis of three distinct hydropower projects reveals unique challenges and opportunities, underscoring the heterogeneous nature of projects and the need for location-specific planning and strategic management. This study provides crucial insights for sustainable development in renewable energy, laying the foundation for future research and policy in similar hydroclimatic settings.
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