Spatio-temporal patterns of land use and land cover, and their impact on groundwater quality in the industrialized Muvattupuzha basin

Rapid urbanization and industrialization drive profound land use and land cover (LULC) transformations across India, placing unprecedented pressure on groundwater resources. This study presents a two-decade (2003-2023) spatio-temporal assessment of LULC dynamics and groundwater quality in the industrialized Muvattupuzha River Basin, Kerala. Multi-temporal Landsat imagery was classified using the Support Vector Machine (SVM) algorithm, achieving high classification performance (overall accuracy 89%, Kappa 0.86). Results reveal a striking 32.09% expansion of built-up areas, accompanied by a 17.91% decline in forest cover and a 4% reduction in agricultural land, reflecting accelerated urban sprawl and landscape conversion. The Entropy-based Groundwater Quality Index (EGWQI) exhibited a strong inverse relationship with built-up areas (r = - 0.91) and a highly positive association with forests and water bodies (r ≥ 0.98), underscoring the buffering role of natural ecosystems. Although 86.7% of wells remain in the 'Excellent' category, persistent contamination hotspots were identified near industrial and agricultural clusters, with risks amplified during monsoonal runoff events. Proximity and correlation analyses confirmed that industrial zones and quarries are critical drivers of localized groundwater degradation. These findings highlight the urgent need for integrated land-water governance, implementation of green infrastructure, and strict effluent management protocols to mitigate anthropogenic impacts and safeguard long-term groundwater sustainability in rapidly urbanizing tropical basins.