Groundwater is a critical resource that supports human health, agricultural productivity, maintaining ecosystems and economic development, particularly in fragile mountainous regions like the lesser Himalayas. This study integrates an Entropy-based Water Quality Index (EWQI) with Geographic Information Systems (GIS) and chemometric analysis to comprehensively appraise groundwater quality in rapidly urbanizing Mandi City, Himachal Pradesh, situated in the Lesser Himalayas. Forty groundwater samples were systematically analysed to assess key physicochemical properties. The physicochemical analysis showed the cations concentration declined in the sequence Mg2+ > Ca2+ > Na+ > K+, while the major anions were distributed as Cl– > HCO₃^ - > SO₄^{2 - } > F–. The EWQI results identified Sanyarad and Mangwain wards as zones requiring immediate intervention. The Principal Component Analysis (PCA) and correlation analysis revealed that that groundwater chemistry is primarily governed by ion exchange, mineral dissolution, and anthropogenic factors such as agricultural discharge and surface runoff. A strong correlation between total hardness, electrical conductivity and major ion concentration further confirmed the impact of both geogenic and anthropogenic factors. Protecting groundwater in the Himalayan region is essential to ensure long time water security, ecological balance and sustainable development. The finding of this study highlights the urgent need for sustainable management of groundwater aligned with Sustainable Development Goal (SDG) 6. It contributes to the global agenda for clean water and sanitation through strategic resource management.
Awasthi et al. (2026) studied this question.