Effect of urban thermal characteristics on wetlands based on remote sensing and GIS

Owing to urbanization rapidly and strongly resulting in the variation of urban land surface feature and energy circulation, urban development and its thermal feature change are tied together. This paper takes land surface temperature (LST) as the instruction factor of thermal feature, and selects satellite TM images acquired at different urban development stages to analyze the relationship between LST variation and urban sprawl. Then, together with Beijing wetland 2007 census data, the relationship between urban wetlands and urban thermal environment and the change of LST in different wetland buffer distance are analyzed with GIS spatial analysis techniques. (1) Due to the urban sprawl and the thermal inertia feature change of land surface, the variation of thermal feature is more and more serious, which is tied together with the urban development. On the other hand, during the retrieval of land surface temperature, if the content of atmospheric water vapor is calculated with remote sensing data and monitoring data observed with ground stations respectively, the difference of LST results is bigger in hill than plain zone. (2) Because wetland landscape and urban other surface has a significant difference in the thermal feature, spatial distribution of wetland and low-temperature zone in urban region are a very good positive correlation. Further more, analyses of relationship between wetlands and land surface temperature in different buffer distance have been done. Mean of the maximum regulation distance is about 267.34 meters for the typical urban wetlands.