Research On Interpreting Land Surface Temperature And Fitting Air Temperature From Remote Sensing In Shanghai

With the development of city economy and urban expansion, the thermal environment change, represented by urban heat island (UH) effect, is becoming an influential factor of the city environment. China, as the largest developing country, is experiencing rapid urbanization. Researching spatial-temporal evolvement of thermal environment in the cities, establishing the protection and improvement plan for high temperature condition in cities have already become critical tasks. Shanghai is a typical international metropolis by high level urbanization and high population density. Researching the characteristics and its evolvement of UHI in Shanghai will provide technical supports for improving the living environment, the urban planning and land use planning.In this paper, the temporal and spatial variations of Shanghai in last decade are researched by interpreting surface thermal field from the Landsat images. The air temperature is fitted from MODIS images and the measured data of weather stations so that specific spatial distribution of air thermal field can be got and the spatial distribution of air thermal field and structural characteristics of UHI can be researched. In the end, the surface thermal field and the air thermal field of Shanghai are compared to disscuss the similarities and differences of UHI form between them.The results show that the area of high temperature experiences a process of increasing, decreasing and multi-center distribution in surface thermal field from1997to2008. It is closely related with the adjustment of industrial layout and planting of large-scale green of Shanghai in the past10years. Center district, Pudong district, Minhang district and Baoshan district is the4main centers of UHI in surface thermal field. Jiading district, Songjiang district and so on are becoming new UHI centers in the same time. With the rapid expansion of built-up area in the last decade, the surface thermal field of UHI has a significant character of multi-center in Shanghai.In the land of Shanghai, the interpreting surface temperatures from MODIS images in spring and autumn are more suitable to fit air temperature than in summer and winter. The heat island intensity is about3-4℃in the air thermal field. The heat island intensity is little larger in spring than in autumn. In the spatial distribution, the relatively high temperature regions in Shanghai temperature thermal field are mainly concentrated in the center and northeast region of the city. The main central feature of urban heat island is more obvious in the center district.There are significant differences in the spatial distribution between surface thermal field and air thermal field. The changes in landuse have more direct impact to the surface thermal field, such as green building, urban development, and industrial layout adjustment. The surface thermal field of UHI has a significant character of multi-center in Shanghai, but the main central feature of urban heat island is more obvious in the center district.