Environmental hazards of water scarcity: the role of Varthur Lake’s water quality in groundwater depletion

Water scarcity is an escalating global issue, intensified by the declining quality of surface water bodies. This study examines the link between surface water pollution in Varthur Lake and its impact on groundwater depletion, highlighting the environmental hazards associated with water scarcity. Varthur Lake, located in the rapidly urbanizing Bangalore region of India, has seen severe water quality deterioration due to industrial effluents, untreated sewage, and agricultural runoff. Over nearly 2 years (July 12, 2022, to May 22, 2024), water quality data from the Karnataka State Pollution Control Board (KSPCB) was analyzed. Key parameters such as pH, COD, BOD, Dissolved Oxygen, Turbidity, Conductivity, Chloride, and Nitrate were assessed using machine learning techniques and multivariate statistical analyses, including PCA, Canonical Correlation Analysis (CCorA), and Factor Analysis (FA). Findings indicate that elevated levels of Chemical Oxygen Demand (COD) and Chloride significantly contribute to organic and inorganic pollution, worsening groundwater depletion. Managing BOD, pH, and Dissolved Oxygen is crucial to preventing further adverse impacts on groundwater quality. This research emphasizes the urgent need for integrated water management strategies, combining pollution control and sustainable water use to tackle the intertwined challenges of surface water pollution and groundwater scarcity. The insights provided can guide policymakers and stakeholders in developing effective interventions to protect water resources and ensure environmental sustainability in the region.