Identification of Urban Heat Island Effect on Land Use Land Cover Changes

Abstract

The effect of urban heat island (UHI), characterized by higher temperatures in urban areas compared to surrounding rural areas, is a significant consequence of rapid urbanization. As cities continue to grow and attract more people, the UHI effect intensifies due to increased heat-absorbing surfaces and reduced green spaces. This can lead to various environmental and health issues, specifically affecting vulnerable populations. This study investigates the phenomenon of UHIs in the Kalutara district of Sri Lanka and examines the relationship between Land Use Land Cover (LULC) changes, urbanization, and the intensity of UHIs. Landsat satellite images from 1991, 2001, 2011, and 2021 were analyzed using Remote Sensing and Geographic Information System (GIS) techniques to create land Surface Temperature (LST) maps and LULC maps. The results show a significant expansion of urban areas and a reduction in green areas within the Kalutara district over the study period, accompanied by an increase in the intensity of UHIs. Regression analysis indicates a negative correlation between the percentage of green areas and LST, highlighting the cooling effect of vegetation. Conversely, a positive correlation is found between LST and the percentage of urban areas. The research demonstrates the spread of UHIs from limited urban centers in 1991 to larger urban areas and adjacent regions in 2021. The findings emphasize the need for sustainable land management practices, preservation of green areas, and effective urban planning strategies to mitigate the adverse effects of UHIs.