Correlation between Urban Thermal Environment Effect and Land Use Pattern in Changchun

We obtained land surface temperature data for the city of Changchun and analyzed the spatial patterns of urban heat field distribution,then quantitatively described the land temperature characteristics of different land use types using ASTER and Spot data and GIS spatial analysis methods to study the effect of different spatial combinations of land use types on the urban thermal environment.The results showed a marked heat-island effect in the built-up area of Changchun,and prominent differences in land surface temperatures inside the heat island.The land surface temperature at the center of the heat island was relatively lower.Land surface temperatures for different kinds of urban land use had obvious discrepancies,with higher land surface temperature for industrial land and lower temperature for water.The descending order of the mean land surface temperature for every land use type was: industrial land,road site,commercial land,residential land,public building,other sites,public facilities,greenbelt,water.The spatial pattern of land use influenced the urban thermal environment,and mean land surface temperature for different kinds of urban land use showed remarkable discrepancies based on land use proportions in grid cells of 500m×500m.The descending order of the mean land surface temperature of land use type based on the 500m grid cells was: industrial land,commercial land,residential land,public building,other sites,road site,public facilities,greenbelt, water.Vegetation and water were significant in reducing the heat-island effect.The effect of water in weakening the land surface temperature is stronger than that of greenbelts.Land surface temperature of grid cells containing vegetative areas or water decreased gradually with increasing proportions of these land cover types,and when the proportion increased at the same rate,the effect of water was stronger than that of greenbelt in reducing the land surface temperature,and the decline in temperature can be simulated by linear equations.So when cities create vegetated areas,increasing the proportion of water is an even more effective way to reduce land surface temperatures.In addition,ameliorating urban thermal environment and urban heat-island effects should pay attention to the different spatial combination and distribution of land use types,and this is an area which would benefit from further study.