Evaluating groundwater potential in water-deficit laterite zones of Eastern India using RS and GIS techniques, combining an analytical hierarchical process for sustainable water resources management

Abstract

Sustainable groundwater management in water-deficit, laterite-dominated regions need urgent planning, which involve accurate identification of groundwater potential zones (GWPZs). While unsustainable water extraction has exacerbated groundwater availability in laterite zones, laterite is globally known for its limited groundwater potential but has received relatively little research attention. Therefore, the present study aims to examine the role of laterite formation on groundwater potentiality and its relationship with the stage of groundwater development in Paschim Medinipur district of West Bengal in eastern India. This study integrated cost-effective and efficient time-saving tools like remote sensing, and GIS and to produce thematic map layers for overlay analysis and analytical hierarchy process (AHP) to delineate the GWPZs precisely using n = 10 parameters, while a consistency check was performed prior to the integration of these parameters to ensure low subjectivity in the GWPZ. The three identified GWPZ classes cover 30% of ‘good’, 44% of ‘moderate’ and 26% of ‘poor’ zones. The yield data and water level fluctuation analysis revealed that 70% and 60% match the delineated GWPZs. The cross-validation with the receiver operating characteristic curve also demonstrated good (75.1%) prediction accuracy. We found that hydrogeological factors like laterite formations witness around 80% of moderate to poor GWPZ, while poor GWPZ covers half of the laterite belt. However, flood plains and valley fill deposits in the lateritic parts demonstrate moderate to good GWPZ, suggesting laterite formation at variable depths that control groundwater recharge potential. The laterite regions with lower groundwater recharge potential have experienced a 17% increase in water extraction compared to non-laterite areas. Whereas four blocks within the district are partly overlapped with laterite formations and poor GWPZ, which encounter high stages of groundwater development (70–90%), leading to semi-critical to critical conditions. It is attributed to anthropogenic perturbations and hydrogeological conditions, which need urgent planning to ensure sustainable groundwater usage.