Groundwater depletion in India: the influence of seasonal precipitation and land use land cover

TL;DR

India's groundwater is rapidly depleting, especially in the north, due to seasonal rainfall changes and land use shifts like urbanization and cropland expansion.

Contribution

The study identifies regional and temporal correlations between groundwater levels, seasonal precipitation, and land use changes using multi-source datasets.

Findings

Northern India shows a negative correlation between groundwater levels and urbanization and cropland expansion.

Seasonal precipitation variability is most severe in northeastern India.

Land use changes include significant increases in croplands, deciduous forests, mixed forests, and urban areas.

Abstract

The rapid depletion of groundwater across India has been revealed through data from the Gravity Recovery and Climate Experiment (GRACE) satellites, particularly in the northern plains. In India, groundwater supports more than 60% of the irrigated area. The impact of seasonal precipitation and land use land cover change (LULCC) on groundwater was investigated through a correlation analysis of multi-source datasets. The data comprised of regional-level monthly precipitation data from ECMWF Reanalysis v5 (ERA5), LULCC data from the NASA MODIS satellite sensor, and groundwater storage estimates derived from the GRACE satellites’ Center for Space Research (CSR) RL06 Mascon solutions alongside the global land data assimilation system (GLDAS) products. Analysis revealed substantial variability in seasonal precipitation, with the steepest declines observed in northeastern India. Significant expansions in land use types were found for croplands (9%), deciduous broadleaf forests (53%), mixed forests (21%), and urban areas (5%). In northern regions, a negative correlation between groundwater levels and both urbanization and cropland expansion was observed. Moreover, the relationship between seasonal precipitation and groundwater storage demonstrated marked regional and temporal differences. These findings underscore the necessity for integrated water management strategies, including optimizing and diversifying water sources for agriculture, promoting aquifer recharge, and enhancing wastewater treatment practices.

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