Intensity and Pattern of Land Surface Temperature in Hat Yai City, Thailand

Abstract

Land Surface Temperature (LST) is an important factor in global climate. LST is governed by surface heat fluxes, which are affected by urbanization. In order to understand urban climate, LST needs to be examined. This study aimed to investigate the intensity and pattern of LST and examine the relationships between LST and the characteristics of urban land use, indices, and population density in Hat Yai City. Landsat 5TM images were used for interpretation of land use characteristics and derivation of LST, normalized difference built-up index (NDBI) and normalized vegetation index (NDVI). The characteristics of land use were classified into 4 types: commercial/high density residential, medium density residential, minimum density residential and vegetation cover/park. The average maximum and minimum LST derived from Landsat 5TM were 25.9, 33.7 and 15.8 °C, respectively. The areas with high LST were located principally in central built-up areas, slightly northwest-southeast of the study area, including the commercial center and the newly expanded residential areas. The LST pattern was well related to land use types and population density. The relationship between LST and NDVI however portrayed negative correlation, while that between LST and NDBI highlighted a positive correlation. It is concluded that NDVI and NDBI can be used to evaluate the risk of Urban Heat Island (UHI) and may help city managers better prepare for possible impacts of climate change. doi: 10.14456/WJST.2015.7