Urban expansion and urban heat island effects on Bangkok metropolitan area in the context of eastern economic corridor

Abstract

The unprecedented and fast urban expansion process can violate the livability of cities by forming Urban Heat Island (UHI) and exposing the public to heat related health risk due to vegetation area declination and urban area inclination. The study is focused on the changes of Land Use Land Cover (LULC), Land Surface Temperature (LST), UHI, Urban Density (UD) and Urbanization Rate (UR) of Bangkok Metropolitan Area (BMA) along with the development of Eastern Economic Corridor (EEC) Project. We used Landsat-7, Landsat-8, and Sentinel-2 data from 2015 to 2022 to perform the analysis. Different normalized indices are computed to achieve the high accuracy of LULC result maps. UHI maps are computed by LST maps and UD is computed by dividing the urban area by the total area of the resulted LULC Maps. UD of each study year is used to generate Ring Map to present the temporal distribution of urban growth. Analysis results stated that 8.4% of increased urban areas can create 3.15 °C increased in LST within an 8-years period. For the study periods (2015, 2017, 2021, and 2022), the computed average LST in Bangkok Province were 27.49 °C, 30.99 °C, 30.91 °C, and 31.22 °C respectively. Analysis results of UD and UR stated that the urban areas in the BMA shifted from 1053.91 to 1177.7213 km2, corresponding to the urban proportion in land cover structure of 67.1% and 75.5% in 2015 and 2022, in turn. Therefore, the study suggested policy makers and city planners to apply urban resilience and sustainable urban development to reduce the risks and provide effective solutions.