Remote sensing-based assessment of land use/land cover changes and climate variability in Akkulam Lake, Kerala, India

Urban lake systems in Thiruvananthapuram play a crucial role in flood buffering, groundwater recharge, and sustaining urban water security in a monsoon-driven environment experiencing rapid urban expansion. Akkulam Lake has been subject to sustained human interference for over two decades, raising serious concerns about its ecological integrity and hydrological functioning. The present study adopts a multi-temporal geospatial approach to analyze land-use and land-cover changes within the lake’s watershed from 2000 to 2024 and to examine their relationship with surface thermal dynamics and soil erosion processes. Satellite imagery was processed using supervised classification techniques, supported by accuracy assessment and spectral indices to quantify shifts in vegetation cover, expansion of built-up areas, and changes in surface water extent. Land surface temperature and surface urban heat island analyses were conducted to evaluate the influence of urbanization on local microclimatic conditions. Further, soil erosion risk was modeled using the Revised Universal Soil Loss Equation within a geographic information system framework to identify spatial patterns of vulnerability. The findings reveal a significant shift toward impervious surfaces at the expense of vegetation and wetlands, leading to elevated surface temperatures, increased thermal stress, and altered hydrological responses. Erosion modeling further identifies emerging hotspots that may intensify sediment inflow and accelerate lake degradation if left unmanaged. Thus, the study highlights the cumulative impacts of rapid urban growth and the need for geospatially guided, watershed-scale interventions to enhance urban water resilience and sustainable lake management in Kerala.