Reviving the “Ganges Water Machine”: where and how much?

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dc.creatorMuthuwatta, Lal P.
dc.creatorAmarasinghe, Upali A.
dc.creatorSood, Aditya
dc.creatorLagudu, S.
dc.date2017
dc.date2017-09-08T04:41:49Z
dc.date2017-09-08T04:41:49Z
dc.date.accessioned2026-06-27T18:35:07Z
dc.descriptionRunoff generated in the monsoon months in the upstream parts of the Ganges River basin (GRB) contributes substantially to downstream floods, while water shortages in the dry months affect agricultural production in the basin. This paper examines the potential for subsurface storage (SSS) in the Ganges basin to mitigate floods in the downstream areas and increase the availability of water during drier months. The Soil and Water Assessment Tool (SWAT) is used to estimate “sub-basin” water availability. The water availability estimated is then compared with the sub-basinwise unmet water demand for agriculture. Hydrological analysis reveals that some of the unmet water demand in the subbasin can be met provided it is possible to capture the runoff in sub-surface storage during the monsoon season (June to September). Some of the groundwater recharge is returned to the stream as baseflow and has the potential to increase dry season river flows. To examine the impacts of groundwater recharge on flood inundation and flows in the dry season (October to May), two groundwater recharge scenarios are tested in the Ramganga sub-basin. Increasing groundwater recharge by 35 and 65 % of the current level would increase the baseflow during the dry season by 1.46 billion m3 (34.5 % of the baseline) and 3.01 billion m3 (71.3 % of the baseline), respectively. Analysis of pumping scenarios indicates that 80 000 to 112 000 ha of additional wheat area can be irrigated in the Ramganga sub-basin by additional SSS without reducing the current baseflow volumes. Augmenting SSS reduces the peak flow and flood inundated areas in Ramganga (by up to 13.0 % for the 65 % scenario compared to the baseline), indicating the effectiveness of SSS in reducing areas inundated under floods in the sub-basin. However, this may not be sufficient to effectively control the flood in the downstream areas of the GRB, such as in the state of Bihar (prone to floods), which receives a total flow of 277 billion m3 from upstream sub-basins.
dc.identifierhttps://hdl.handle.net/10568/83360
dc.identifier.urihttp://hdl.handle.net/123456789/160097
dc.languageen
dc.publisherCopernicus GmbH
dc.rightsOpen Access
dc.sourceMuthuwatta, Lal; Amarasinghe, Upali A.; Sood, Aditya; Lagudu, S. 2017. Reviving the “Ganges Water Machine”: where and how much? Hydrology and Earth System Sciences, 21:2545-2557. doi: 10.5194/hess-21-2545-2017
dc.subjectsurface water
dc.subjectrunoff water
dc.subjectmonsoon climate
dc.subjectupstream
dc.subjectflooding
dc.subjectriver basin management
dc.subjectgroundwater recharge
dc.subjectwater storage
dc.subjectwater availability
dc.subjectwater demand
dc.subjectagriculture
dc.subjectsoil management
dc.subjectsoil water
dc.subjectflood control
dc.titleReviving the “Ganges Water Machine”: where and how much?
dc.typeJournal Article

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