River Ganga drying up in summers due to groundwater depletion: Study
According to recent study conducted by IIT-Kharagpur, River Ganga has witnessed unprecedented low levels of water in several lower reaches in last few summer seasons. The study was carried out under IIT-KGP Science and Heritage Initiative (SANDHI) Initiative, which focuses on river systems and its relationship with settlement system. It had used combination of satellite images of groundwater levels of Ganga, numerical simulations and chemical analyses to draw the conclusion.
Highlights of Study
Drying of Ganga River in recent years during summer seasons is possibly related to groundwater depletion in Gangetic aquifers. The decline of groundwater inflow (base flow) is also impacting health of river. Present day base flow to Ganga from adjoining aquifers may be third or more of total river water volume in pre-monsoon months. The base flow might have dipped by 50% from beginning of irrigation-pumping phase in 1970s. In forthcoming summers, for next 30 years, groundwater contribution to river Ganga will continue decreasing. This trend can lead to disastrous effect on riverine ecology and lead to food scarcity for 115 million people in Ganga basin.
Significance of Study: It is of interest to hydrology, global change community and policymakers. It can help general public understand wider implications of groundwater depletion. It also brings out scientific reasons for the decreased flows of the river Ganga, especially in the lower reaches. The findings will be extremely helpful in providing quantitative data for future planning of water resources projects in Ganga basin.