Impact of Land Use Land Cover Change on Land Surface Temperature in Small and Medium Sized Cities in South Asia: A Remote Sensing Approach

Rapid urbanization impacts the surrounding urban environment in multiple ways, with the Urban Heat Island (UHI) effect being one of the most critical, driven by concrete surfaces and anthropogenic activities that create a rural–urban temperature difference. Climate change, coupled with these land use changes, increases the vulnerability of city dwellers to extreme heat. South Asia, home to millions of urban residents, faces heatwaves that are rising in both intensity and frequency. This study examines Land Use Land Cover (LULC) change in nine cities across five South Asian countries between 2003 and 2023 and explores its correlation with Land Surface Temperature (LST). Using the Random Forest machine learning model on the Google Earth Engine (GEE) platform, LULC classification was performed with 70–120 training points per land type for the year 2003 and 2023. Results show that built-up areas expanded in all cities, while vegetation, water, and other land types declined, except in Ahmedabad, where greenery increased due to planned vegetation. The LULC classification achieved high overall accuracy (>96%) with moderate validation accuracy. Mean annual LST increased across all cities, averaging 3.2°C. Correlation analysis indicates that built-up areas exert the strongest influence on LST, vegetation provides moderate cooling, and water has little impact due to its limited extent.