A geospatial assessment of land use changes and their influence on land surface temperature in Koch Bihar district, West Bengal

Abstract

Land use and land cover (LULC) changes significantly impact regional climate, particularly their influence on land surface temperature (LST). This study employs remote sensing (RS) and geographic information system (GIS) techniques to assess LULC transitions and their thermal effects in the Koch Bihar district of West Bengal over the past three decades (1991–2021). Previous studies have predominantly concentrated on assessing land-use transformations, with limited attention given to the LST dimension and the systematic identification of major conversion patterns and temporal trends. Multi-temporal Landsat imagery was used to classify vegetation, agricultural land, built-up areas, fallow land and water bodies, revealing significant transformations. Results showed that agricultural land expanded by 6.31 %, while built-up areas increased by 5.18 %, primarily at the expense of vegetation cover (10.81 %), contributing to significant LST modifications. Seasonal temperature trends indicate a rise in summer LST from 37.52°C (1991) to 39.76°C (2021) and an increase in autumn temperatures, highlighting the urban heat island (UHI) effect. In the study area, Normalized Difference Vegetation Index (NDVI) values declined over time, confirming a loss of vegetative cover and reflecting intensified urbanisation. The spatial trend analysis indicates that urbanisation, agricultural intensification and deforestation have led to higher thermal loads across the region. The outcomes of this study may serve as a valuable resource for policymakers and enhance public awareness by offering a scientific foundation for sustainable land use planning and effective management strategies.