The Indo-Gangetic Basin accounts for about a quarter of global groundwater extraction, supporting agriculture and livelihoods in large parts of South Asia, one of the most densely populated regions of the world. Sustainability of this resource is clearly of concern, given the levels of extraction for irrigation and drinking. In this study led by the British Geological Survey, researchers combine field measurements with existing datasets to reveal patterns of groundwater extraction over the last decade. The study finds that groundwater levels are falling in 30% of the basin, particularly near major cities, but are stable or even increasing across the other 70% due to recharge from leaky irrigation canals. However, it also finds that 60% of groundwater up to a depth of 200 metre, is contaminated by arsenic or salt. Contamination, therefore, presents a larger threat than depletion, making large volumes of groundwater unfit for drinking and irrigation.
The Department for International Development’s South Asia Research Hub supported this research as part of its Climate Research and Information Services in South Asia (CRISSA) programme.
MacDonald, A.M; Bonsor, H.C; Ahmed, K.M; Burgess, W.G; Basharat, M; Calow, R.C. Dixit, A; Foster, S.S.D; Gopal, K; Lapworth, D.J; Lark, R. M; Moench, M; Mukherjee, A.; Rao, M.S; Shamsudduha, M.; Smith, L.; Taylor, R. G; Tucker, J.; van Steenbergen, F.; Yadav, S.K. Groundwater quality and depletion in the Indo-Gangetic Basin mapped from in situ observations. Nature Geoscience (2016) [doi:10.1038/ngeo2791]
Groundwater quality and depletion in the Indo-Gangetic Basin mapped from in situ observations (subscription or purchase of article required)