Impact of Land Conversion on Land Surface Temperature Over the Coastal Area: A Spatiotemporal Study of Cox’s Bazar District, Bangladesh

Sustainable methods to manage and predict environmental degradation can be achieved through changing land use and land cover patterns (LULC) and regular monitoring of land surface temperature (LST). LST increases impact the environmental quality of urban areas and significantly increase the number of urban hot spots (UHS). The aim of this study is to assess the impact of urban development on land cover area (LCA) and LST in Cox’s Bazar. Based on remote sensing data collected in 1990, 2000, 2010, and 2020, the study examines regional trends in LST and LULC. According to the study’s results, the largest LST ever recorded occurred in 2020 at a temperature of 55 °C. However, the lowest LST value was recorded between 2000 and 2010 at 17.93 °C. During the period from 2000 to 2010, significant fluctuations in LST were observed in most areas. Moreover, the vegetation area decreased by 144,947 km² between 1990 and 2020, while the water area decreased by 119,541 km². In contrast, the built-up area of Cox’s Bazar grew by 200,707 km². The maximum likelihood classification method was used to assess land use and land cover (LULC) changes between 1990 and 2020. During this time, the built-up area grew by 6.669% annually, which represented a significant expansion. This growth is largely due to the sharp increase in refugee numbers, which has led to forests and other natural vegetation being cleared to make room for infrastructure and emergency shelters. Changes in LULC were found to correlate with this increase in LST. According to the Normalized Difference Vegetation Index (NDVI), plants had the highest abundance value in 2010 with a value of 0.98 and the lowest abundance value in 2020 with a value of 0.34. In contrast, the Normalized Difference Built-Up Index (NDBI) had a standard deviation of 0.08 and reached its maximum average value of 0.15 in 2018. This indicates an increase in developed land as well as fill, sand, and vacant land areas indicating steady growth in developed areas. This study analyzes the current state of the area compared to several years ago when it was in its natural state. The results of this study have the potential to support relevant authorities and international humanitarian organizations in developing a land management strategy that is inclusive, sustainable, and environmentally friendly to ensure strategic humanitarian operations in the region while protecting forest biodiversity.