Assessment of environmental degradation of lakes of Nainital district: an ecohydrological perspective

Abstract Human activities have degraded lakes in Uttarakhand, endangering their vital role urban sustainability, which includes providing essential services like water supply, flood mitigation, agriculture support, and biodiversity conservation the Himalayan region. This study focused on Nainital district lakes, utilizing remote sensing GIS techniques to assess condition. Time series Landsat 8 satellite imageries acquire by USGS earth explorer from 2017 2022 were captured, pre-processed, subjected spectral-based classification algorithms ArcGIS software calculate Normalised Difference Vegetation Index (NDVI), Water (NDWI), Built-up (NDBI) indices changes vegetation, bodies, build-up area around respectively. The results indicate a decrease built-up areas for 2022: Naini Lake (1.42%), Bhimtal (1.83%), Naukuchiatal (1.45%), Sattal (2.18%), Khurpatal (2.25%), Sariyatal (1.3%). Additionally, Bhimtal, Naukuchiatal, exhibited reductions shrub grass vegetation approximately 12%, 16%, 0% over five-year period. Notably, Khurapatal demonstrated significant decreases areas, likely attributed restoration efforts or landslides. Findings emphasize need conservation, sustainable land-use practices, effective management protect lake ecosystems.