Multivariate Assessment of Groundwater Depletion and Recharge Prospect in a Sub-tropical Basin of Eastern India

Abstract

Abstract The present study aims to highlight the groundwater-stress condition of the Quaternary 一 recent alluvial region escalated by anthropogenic extraction of water resources in the western Bengal Basin (Purba Bardhaman, West Bengal, India). With the rapid development of irrigation technology, high crop yield, water- consumed rice varieties, and high cropping intensity, the farmers of the river basin go to deeper underground aquifers (>180 m bgl) to extract water for summer rice (Boro) cultivation. In this study, the five semi-critical blocks (Mangolkote, Bhatai; Manteswai; Purbasthali II, and Memari II) of Purba Bardhaman district have experienced statistically significant pre-monsoon fall (0.404 m yr- 1 to 1.099 m yr-1) and post-monsoon fall of groundwater level from 0.486 m yr-1 to 2.214 m yr-1. Principal component analysis reflects that annual irrigation draft, annual replenishable groundwater unit, net groundwater availability, Boro rice cultivation area, area to be covered on each day irrigation for Boro, and daily pump discharge required for Boro irrigation are the key factors to escalate groundwater decline. This study reveals that Galsi II, Bardhaman I and II, Katwa I, and Purbasthali I blocks will experience a water-stress or groundwater drought in future. The model of groundwater recharge potential zone shows four principal categories of groundwater prospect area in the basin, viz., poor (0.08 %), moderate (5.78 %), good (68.96 %), and very good (25.18 %). These findings provide the relevant information for planners of groundwater resources to upscale groundwater management procedures and enhance the sustainability of agricultural systems in the study area.