A decadal analysis of land surface temperature dynamics in response to urban expansion and vegetation loss in Faridpur

Abstract

Land-atmosphere interactions, urban thermal environments, and the impacts of land-use and land-cover (LULC) alterations are effectively grasped through the precise measurement of land surface temperature (LST). In this work, Landsat-8 OLI/TIRS imagery from 2014 and 2024 was utilized to track ten-year variations in LST and plant health across Faridpur District of Bangladesh. Supervised classification was used to categorize the landscape into four specific LULC categories: vegetation, bare soil, built-up areas, and water bodies. Each examined year featured calculations for both LST and the Normalized Difference Vegetation Index (NDVI). Between 2014 and 2024, a massive urban expansion from 21.35% to 45.25% was recorded. Conversely, total vegetated area was reduced from 41.09% down to 25.87% over the same timeframe. A widespread surface warming pattern was clearly established by the thermal metrics. Specifically, the regional maximum LST increased from 42.69 °C to 45.33 °C, alongside a minimum LST increase from 15.55 °C to 21.31 °C. The deterioration of thick ecological canopies was signaled by a drop in peak NDVI scores from 0.999 to 0.883 over the past decade. Built-up and bare-soil surfaces primarily showed the highest LST values, according to spatial mapping. Meanwhile, cooler microclimates were sustained by water-covered zones and vegetated patches. These outcomes highlight the urgency of conserving green cover in Faridpur. Moreover, establishing small-scale urban green areas in the rapidly expanding towns and cities across the region is necessary to counteract the thermal consequences of ongoing urbanization.