Your search found 6 records
(Location: IWMI HQ Call no: e-copy only Record No: H051429)
(5.79 MB)
For decades, millions of farmers in Bangladesh have been capturing more water than even the world’s largest dams. They did so simply by irrigating intensively in the summer dry season using water from shallow wells. The ability to use groundwater to irrigate rice paddies during the dry seasons (January to May) helped Bangladesh become food self-sufficient by the 1990s, which was no small feat for one of the most densely populated countries in the world. Researchers proposed that lowering of the groundwater table as a result of intensive irrigation practices in the dry season created conditions for recharge from monsoon rains (June to September), which then replenishes the groundwater (1). On page 1315 of this issue, Shamsudduha et al. (2) present a quantitative analysis of this depletion-replenish process and show that this recharge has indeed been happening at a large scale, in a process they call the Bengal Water Machine (BWM).
(Location: IWMI HQ Call no: e-copy only Record No: H051446)
(7.73 MB)
(Location: IWMI HQ Call no: e-copy only Record No: H051447)
(7.50 MB)
(Location: IWMI HQ Call no: e-copy only Record No: H051557)
(16.50 MB) (16.5 MB)
The Meki catchment in the Central Rift Valley basin of Ethiopia is currently experiencing irrigation expansion and water scarcity challenges. The objective of this study is to understand the basin’s current and future water availability for agricultural intensification. This was done by simulating scenarios through an integrated SWAT-MODFLOW model to assess the water balance. The scenarios were co-developed with communities who expressed their aspirations for agricultural intensification in conjunction with projected climate change. The results show that with the present land use and climate, the catchment is already water stressed and communities cannot meet their irrigation water demand, particularly in the first irrigation season (October–January). However, in the second irrigation season (February–May) water resource availability is better and increasing irrigated area by 50% from the present extent is possible. With a climate change scenario that favours more rainfall and shallow groundwater use, agricultural intensification is feasible to some extent.
(Location: IWMI HQ Call no: e-copy only Record No: H051807)
(9.32 MB) (9.32 MB)
Study region: Lake Tana sub-basin of the Upper Blue Nile River Basin, Ethiopia.
Study focus: Groundwater use for small-scale irrigation is increasing in the Lake Tana sub-basin. However, the abstraction amount and its impact are not well understood. In this study, a new methodological approach was utilized to estimate the irrigation water abstraction amount, which is based on groundwater level monitoring before, during, and at the end of the irrigation season (2021/2022). The monitoring was conducted on 361 hand-dug wells distributed throughout the sub-basin, which is subdivided into East, Southwest, and North zones.
New hydrological insights for the region: Groundwater abstraction for irrigation and associated groundwater level decline estimates are 10.6 × 106 m3 and 2.43 m in the East, 4.2 × 106 m3 and 3.23 m in the Southwest, and 0.6 × 106 m3 and 1.32 m in the North. These abstractions account for 103%, 97%, and 62% of the mean annual groundwater recharge in the East, Southwest, and North zones, respectively. Groundwater is overexploited in the East and Southwest zones although, at the sub-basin scale, the amount of groundwater used for irrigation is small compared to the renewable groundwater resource. However, if groundwater-based irrigation continues to expand especially in the East and Southwest zones, groundwater scarcity at the local scales will worsen. Adaptive management strategies are required to minimize the potential adverse effects on groundwater resources.
6 Indika, S.; Hu, D.; Wei, Y.; Yapabandara, I.; Cooray, T.; Makehelwala, M.; Jinadasa, K. B. S. N.; Weragoda, S. K.; Weerasooriya, R.; Pang, Z. 2023. Spatiotemporal variation of groundwater quality in North Central Province, Sri Lanka. ACS EST Water, 12p. (Online first) [doi: https://doi.org/10.1021/acsestwater.2c00490]
(Location: IWMI HQ Call no: e-copy only Record No: H051914)
(7.18 MB)
This study focused on fulfilling the demand for a comprehensive investigation of groundwater quality in the North Central Province (NCP) of Sri Lanka to achieve United Nations Sustainable Development Goal 6 (Ensure availability and sustainable management of water and sanitation for all). The NCP was selected as the study area due to its highest prevalence of chronic kidney disease with unknown etiology within Sri Lanka. Here, 334 shallow and deep groundwater samples were collected at the end of wet and dry seasons, respectively. Results revealed that elevated and unexpected levels of salinity, hardness, fluoride, nitrate, sulfate, and dissolved organic carbon and the alkaline nature of groundwater were the main issues, and the Ca-HCO3 type was dominant in the groundwater. Water quality index analyses showed that 8.9% and 13.8% of wells had poor quality undrinkable groundwater in wet and dry seasons, respectively. Only 7% of samples were susceptible to sodium and salinity hazards for irrigational use. Reverse osmosis technology with a softening and activated carbon pretreatment process was identified as the most suitable way to treat groundwater with high salinity for many regions of the NCP. The groundwater quality atlas for the NCP created by this study was very useful for making a master plan of safe drinking water supplies and developing and implementing cost-effective water purification technologies in the NCP.
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