Relationships between urban heat island intensity and land use/cover factors based on Landsat ETM+ in urban agglomeration of Guangdong, China

Abstract

Ten cities with different urban sizes located in the Pearl River Delta, Guangdong Province, China were selected to study the relationships between surface urban heat island (S-UHI) intensity and land use/cover factors like urban size, development area, water proportion and mean NDVI, etc. All the cities are almost at the same latitude, show similar climate and have the same solar radiation, the influence of which shall be eliminated during our computation and comparative study. A variance-segmenting method was proposed to compute the S-UHI intensity for each city from the retrieved land surface temperature (LST). Factors like urban size, development area and water proportion were extracted directly from the classification images of the same ETM+ data. The urban mean NDVI value was used to quantify the urban vegetation abundance. Regression and correlation analyses were performed to study the relationships between the S-UHI intensity and these land use/cover factors, and the results show that S-UHI intensity is highly correlated to urban size (r = 0.83) and development area (r = 0.74). It was also proved that negative correlations existed between S-UHI intensity and urban mean NDVI (r = -0.62), and water proportion (r = -0.54). Linear and logarithm functions between S-UHI intensity and land use/cover factors were established respectively.