Monitoring of seasonal change of urban heat island effect in Beijing using Aster data

Abstract

The urban heat island (UHI) refers to the temperature rise of any man-made area, which can make it distinctively protrude as a 'warm island' among the 'cool sea' that the lower temperature of their natural landscape represents. This paper focuses on the monitoring of UHI effect with seasonal change using Advance Spaceborne Thermal Emission and Reflection Radiometer (ASTER) data which is onboard the satellite Terra. Our study area is in central urban area of Beijing within fifth ring road. The ASTER data on January, 27, April 9, June 4, August 31, 2004 in daytime were collected and regarded as winter, spring, summer, and autumn respectively. In order to calculate the urban heat island intensity, the land surface temperatures were retrieved using an iterative way to compare the temperature difference between the urban and surrounding rural area. Some pre-processing procedures such as geometric rectification, radiometric correction, delineating and masking of features, and land cover classification should be performed using satellite images before calculating the UHI. The UHI was divided into normal, weak, strong, very strong, severe and extreme based on the calculated UHI intensity. Our result indicates that the UHI effect is weak, strong and extreme in sprint, summer and autumn respectively, and in winter, the central urban area of Beijing is in an urban heat sink. It means that the UHI effect is different with the seasonal change.