Exploring the influence of land use land cover change on the urban thermal environment

The rapid urbanization in developing countries is accompanied by a significant increase in built-up surfaces, such as concrete structures, buildings, and paved roads, which ultimately results in elevated land surface temperature (LST). Specifically, the middle-tier cities, such as Patna, which is developing at a rapid rate, are experiencing a significant shift in their land use pattern. This trend results in the intensification of the urban heat island (UHI) effect, making cities and towns significantly hotter than rural areas and reducing thermal comfort for residents. To address this issue, the study aimed to analyze the temporal and spatial variation of UHI and its correlation with land use indices in the Patna district, which has a population density well above the national average. UHI and Urban Thermal Field Variance Index (UTFVI) maps were generated to assess the severity of impact of built-up surfaces in the region. The findings revealed a significant increase of 179.72% in the built-up area from 2017 to 2023. The land surface temperature (LST) ranges from 27 °C to 67 °C, with a significant increase in the area of higher temperature ranges. UHI formation reveals that the extent of the very strong heat island zone expanded from the southwest to cover the entire study area by 2023. The UTFVI results indicated that the environmental condition category of the region is deteriorating over time and across space. The results of this study will contribute significantly to the development of strategies for green space planning and enhancing thermal comfort in developing cities.