Abstract
RE: Ganga clean-up: Smaller scale strategies are preferredAbhik Gupta, University professor,Department of Ecology & Environmental Science, Assam University, IndiaOther Contributors:Ben J Kefford, University associate professor,Institute for Applied Ecology, University of Canberra, Australia (16 November 2018)
In this editorial, Shah et al. have revived the "Ganges water machine" (GWM) concept put forward in the 1970’s (1), and advocated for recently (e.g. 2). Essentially, this strategy involves intensive winter and pre-monsoon drawing down of groundwater which are then refilled by monsoon rains, floodwaters and snowmelt. The GWM is designed to increase dependence on groundwater so as to leave more surface water for maintaining environmental flow to flush pollutants from the river. However, this prescription needs to be examined carefully from several standpoints before adoption. Firstly, six of the seven sub-basins where the GWM was assessed to have high efficacy (3) have high arsenic concentrations, and groundwater irrigation has already resulted in widespread As contamination of soil, vegetables, rice, and other crops (4). Secondly, groundwater use for irrigation already accounts for 67% of irrigation water within the Ganges Basin (5). It is not certain how pushing it further would significantly control flood and increase lean-season flow. Thirdly, land subsidence due to intensive pumping may occur in places (2). Instead of going for spectacular action plans, it may be more prudent to implement smaller scale strategies including improvement of discharge water quality and generating mass awareness among riparian communities to adopt eco-friendly practices – with the help of religious and cultural leaders - throughout the Ganges basin.
In this editorial, Shah et al. have revived the "Ganges water machine" (GWM) concept put forward in the 1970’s (1), and advocated for recently (e.g. 2). Essentially, this strategy involves intensive winter and pre-monsoon drawing down of groundwater which are then refilled by monsoon rains, floodwaters and snowmelt. The GWM is designed to increase dependence on groundwater so as to leave more surface water for maintaining environmental flow to flush pollutants from the river. However, this prescription needs to be examined carefully from several standpoints before adoption. Firstly, six of the seven sub-basins where the GWM was assessed to have high efficacy (3) have high arsenic concentrations, and groundwater irrigation has already resulted in widespread As contamination of soil, vegetables, rice, and other crops (4). Secondly, groundwater use for irrigation already accounts for 67% of irrigation water within the Ganges Basin (5). It is not certain how pushing it further would significantly control flood and increase lean-season flow. Thirdly, land subsidence due to intensive pumping may occur in places (2). Instead of going for spectacular action plans, it may be more prudent to implement smaller scale strategies including improvement of discharge water quality and generating mass awareness among riparian communities to adopt eco-friendly practices – with the help of religious and cultural leaders - throughout the Ganges basin.
Original language | English |
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Pages (from-to) | 1-1 |
Number of pages | 1 |
Journal | Science |
Volume | 362 |
Issue number | 6414 |
Publication status | Published - 16 Nov 2018 |