Spatio-Temporal Dynamics of Water Quality in Bheemanakuppe Lake Amidst Anthropogenic Alterations, Bangalore District, Karnataka

Freshwater lakes are indispensable economic, ecological, and cultural lifelines. Urgent action against degradation and biodiversity loss is critical to ensure sustainable water resources, protect human health, and safeguard national economies. In this study, water quality parameters such water quality parameters such as Temperature (27 ± 0.5), pH (7.4 ± 0.1), Total Dissolved Solids (TDS) (360 ± 10), Electrical Conductivity (EC) (460 ± 10), Total Hardness (TH) (122.33 ± 2.52), Dissolved Oxygen (DO) (7.5 ± 0.3), Biological Oxygen Demand (BOD) (1.17 ± 0.15), Chemical Oxygen Demand (COD) (27.67 ± 2.52), Chloride (32.33 ± 2.52), Calcium (82.33 ± 2.52), Magnesium (31.67 ± 1.53), Sodium (27.67 ± 2.52), and Potassium (22 ± 2) were analyzed at Bheemanakuppe Lake in 2024-25. The data were analyzed using Pearsons's correlation matrix and Water Quality Index (WQI) to evaluate the overall health and suitability of lake water. Highly positive correlations were observed between Chloride (Cl) and Sodium (Na) (0.92), as well as between COD and Chloride (0.92). A strong positive correlation was also found between BOD and pH (0.85). In contrast, strong negative correlations were observed between Total Alkalinity (TA) and Sodium, Chloride, and COD (ranging from −0.85 to −0.89). Additionally, Potassium (K) showed moderate negative correlations with BOD and Sodium (approximately −0.75). The Water Quality Index (WQI) was used to condense these parameters into a single, interpretable value, which remained within the “Good†category, with an average of 45.1 during the 2024–2025 period. The study emphasizes the importance of continuous monitoring and the implementation of strategic measures for the preservation and sustainable management of Bheemanakuppe Lake. It also provides valuable insights for local communities, enabling them to make informed decisions to protect and safeguard this vital water resource.