An Analysis Of Time-space Characteristics Of Heat Island Effect Using Landsat Satellite Data In Fuzhou

Land surface temperature(LST) is a major factor of the urban heat island(UHI) research.With the in-depth study of urban thermal environment,how to monitor and calculate LST comes significantly in the current urban thermal environment research. Supporting by RS and GIS,Fuzhou which was an open coastal city and urbanizating rapidly since the period of reform and opening was studied.LST was retrieved from band 6 by three Landsat TM/ETM+ images during the year of 1989,1996 and 2001.Based on retrieved LST maps of the studying area,the author analysed the LST spatial distribution feature and its space-time change law.The water,vegetation,bareness and urban built-up land of study area were extracted with the relevant model,including the expansion law and driving force of urban built-up land.LST of study area was retrieved using Image-based method.According to the density segmentation image,retrieved LST maps of study area were divided into different levels to analyse spatial distribution feature and its space-time change law.Space-time change of UHI intensity was studied through typical sample.The trend and features of UHI was analyzed through a representative profile line.Finally,the relationship between UHI and land cover types was summarized through the method of statistical analysis.The results show that:the area of high-temperature mainly distributes regions of intensive buildings and bareness.The scope of heat island enlarges year by year,and the speed was accelerating,UHI intensity increases gradually,but the speed slows up.The mean of LST from small to large in turn is:water,vegetation,bareness,built-up land,and the variance is:water,vegetation,built-up land,bareness.