Groundwater pumping to increase food production causes persistent groundwater drought in India

TL;DR

This study reveals that increased groundwater pumping for agriculture in India has led to persistent groundwater droughts, with climate factors becoming less influential, emphasizing the need for sustainable water management.

Contribution

It demonstrates the decoupling of groundwater storage from precipitation post-2012 and highlights the dominant role of groundwater pumping over climate in India’s groundwater depletion.

Findings

Groundwater drought persists despite increased precipitation in northwest India.

Groundwater pumping has become the primary factor affecting groundwater storage since 2012.

Vegetation growth influences groundwater storage more than precipitation in northwest India.

Abstract

Rapid groundwater depletion in India is a sustainability challenge. However, the crucial role of climate and groundwater pumping on persisting groundwater drought remains unrecognized. Using the data from Gravity recovery climate experiment (GRACE) satellites and more than 5000 observational wells, here we show that the increase in precipitation in northwest India (NWI) no longer helps to recover from groundwater drought that started after 2012. Groundwater storage anomaly (GWSA) from the GRACE well observations is strongly linked with accumulated precipitation for 153, 105, and 18 months for NWI, northcentral (NCI), and south India (SI). Precipitation and GWSA have decoupled in NWI after 2012 indicating the higher influence of groundwater pumping for crop production than climate. The relative contribution of vegetation growth (R2=0.26) on GWSA is higher than precipitation (R2=0.02) for 2002-2016 in NWI than in NCI and SI. Our findings highlight the urgent need of reducing groundwater pumping in India.