Water accounting for Kanpur metropolitan area in Ganges river basin

Abstract Groundwater is a vital source of irrigation water, and it provides over 80% of the irrigated water supply in Bangladesh. The study aimed to assess the status of irrigation water of the Ganges river basin areas in the middle-west part of Bangladesh through the hydrogeochemical characterization and classification of groundwater. The study parameters were pH, EC, TDS, Ca2+, Mg2+, total hardness, Na+, K+, B, Cl−, HCO3 −, SO 42−, NO3 −, and PO43− along with irrigation water quality index (IWQindex), Na%, soluble sodium percentage, sodium adsorption ratio, residual sodium bicarbonate, magnesium adsorption ratio, permeability index, and Kelley’s ratio. The results showed that most of the water samples were acidic in the pre-monsoon and alkaline in the post-monsoon seasons, and the water type was Ca-HCO3. The significant geochemical process in the area determined was calcite and dolomite mineral dissolution, and there was no active cation exchange, and silicate weathering occurred. The statistical analyses showed that both the geogenic and anthropogenic sources were controlling the chemistry of the groundwater aquifers. Concerning irrigation water quality, the results revealed that all the quality parameters and IWQindex (32.04 to 45.39) were within the safety ranges, except for the EC and total hardness. The study results would be useful for future groundwater monitoring and management of the Ganges basin areas of Bangladesh part.

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Reviving the Ganges Water Machine: why?

Hydrology and Earth System Sciences Discussions ◽

10.5194/hessd-12-8727-2015 ◽

2015 ◽

Vol 12 (9) ◽

pp. 8727-8759 ◽

Cited By ~ 3

Author(s):

U. A. Amarasinghe ◽

L. Mutuwatte ◽

L. Surinaidu ◽

S. Anand ◽

S. K. Jain

Keyword(s):

Water Supply ◽

River Basin ◽

Water Use ◽

Water Demand ◽

Monsoon Season ◽

Subsurface Water ◽

Ganges River ◽

Hot Weather ◽

The Ganges ◽

Ganges River Basin

Abstract. The Ganges River Basin may have a major pending water crisis. Although the basin has abundant surface water and groundwater resources, the seasonal monsoon causes a mismatch between supply and demand as well as flooding. Water availability and flood potential is high during the 3–4 months of the monsoon season. Yet, the highest demands occur during the 8–9 months of the non-monsoon period. Addressing this mismatch requires substantial additional storage for both flood reduction and improvements in water supply. Due to hydrogeological, environmental, and social constraints, expansion of surface storage in the Ganges River Basin is problematic. A range of interventions that focus more on the use of subsurface storage (SSS), and on the acceleration of surface–subsurface water exchange, have long been known as the "Ganges Water Machine". One approach for providing such SSS is through additional pumping prior to the onset of the monsoon season. An important necessary condition for creating such SSS is the degree of unmet water demand. This paper highlights that an unmet water demand ranging from 59 to 119 Bm3 exists under two different irrigation water use scenarios: (i) to increase Rabi and hot weather season irrigation to the entire irrigable area, and (ii) to provide Rabi and hot weather season irrigation to the entire cropped area. This paper shows that SSS can enhance water supply, and provide benefits for irrigation and other water use sectors. In addition, it can buffer the inherent variability in water supply and mitigate extreme flooding, especially in the downstream parts of the basin. It can also increase river flow during low-flow months via baseflow or enable the re-allocation of irrigation canal water. Importantly, SSS can mitigate the negative effects of both flooding and water scarcity in the same year, which often affects the most vulnerable segments of society – women and children, the poor and other disadvantaged social groups.

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