Evaluating the Impact of Land Use/Land Cover Changes on the Surface Urban Heat Island intensity: The case study of Kabul city, Afghanistan

Abstract

The purpose of this paper is to detect the areas which are affected by urban heat island (UHI) based on the relationship between land surface temperature and land use /land cover (LU/LC) changes during 1998, 2011, and 2020 for the major city of Kabul, the capital of Afghanistan, using multispectral and multi-temporal Landsat data (TM and OLI/TIRS). To achieve the objectives, the emissivity corrected land surface temperature method was examined to calculate Land Surface Temperature (LST), and the Land-use/Land-cover map was prepared using the support vector machine (SVM) supervised algorithm. The LU/LC was categorized into five major classes (vegetation, water-body, built-up, bare-land, and soil). According to the LST map estimated by processing the thermal band of the satellite image, areas influenced by Urban Heat Island (UHI) were detected to evaluate their anomalies to the existing LU/LC types. The findings of LST illustrate, that the mean recorded LST in 1998 was 39.42˚C, whereas the mean recorded LST in 2020 was 41.25˚C, which demonstrates a 1.83 ˚C increase for the whole study period. Specifically in 1998 only five districts (1,16,9,15, and 19) were affected by surface UHIs, while in 2011, the surface UHIs influenced areas increased to eight districts (15, 16, 1, 21, 17, 12, 13, and 8), and in 2020, the surface UHIs affected regions are improved to ten districts (1,19, 15,16, 9,17, 22, 11, 13, and 2) over the Kabul City. These variations and improvements are mostly due to the status of LU/LC in the study area, and it demonstrates the strong link between land cover and land surface temperature. Furthermore, Normalized difference vegetation index (NDVI), and normalized difference built-up index (NDBI) were also extracted. The relationship of NDVI and NDBI with LST was evaluated. Based on the results, a strong negative relationship between LST and NDVI was observed, while a positive relationship between LST and NDBI was recorded. The findings of this work show that an increase in non-evaporation areas and a decline in the greenery surfaces increased the LST. Consequently, the outcomes of this study are significant for decision-makers and urban planners to manage the drawbacks of urbanization temperature in arid and semi-arid areas.