Assessment of surface urban heat island effects and associated surface biophysical indicators using MODIS imagery

摘要

This study focuses on using remote sensing for assessment of surface urban heat island and associated surface physical characteristics and selects Changsha city as study area. The TERRA/MODIS images acquired in 2005 for three different seasons were selected to generate land surface temperature maps and surface characteristics. The result showed that UHI effects were significant both in summer and spring. Land surface temperatures were 8°C and 10°C warmer than surrounding rural areas in spring and summer seasons, respectively. Although it is still existed in winter, the UHI effects are not so much significant. Land surface temperature was 4°C warmer than surrounding rural areas in winter. This study uses normalized difference building index (INBI) as indicator of impervious surfaces and investigates the relationship between NDBI and LST. Our analysis indicates there is strong positive linear relationship between NDBI and LST for all seasons. The amount of slop and intercept of linear relationship can indicate the magnitude of UHI for different seasons. Therefore, NDBI provides alternative physical indicator for analyzing LST quantitatively over the seasons for UHI study using remote sensing in an urbanized environment.