Characteristics of Heat Island in Nanjing and Relationship Between Heat Island and Land Use/cover

Landsat TM thermal infrared band data of Nanjing city in July was used in this study and according to single-window algorithm,the land surface temperature of Nanjing city was obtained.Then the urban heat island characteristic of Nanjing city was discussed and the reason of it was analyzed.Through the combination of the remote sensing and geography information system techniques,the land use/cover types of Nanjing were abstracted.Then the thermal radiation character of different land use/cover was analyzed and the relationship between land surface temperature and land use/cover types,especially plant cover was quantificationally analyzed.The results showed that there were three urban heat island centers in summer of Nanjing,and the land surface temperature in city proper was higher than that in suburban district.Through comparison,the average land surface temperature in city proper was 3.5 ℃ and 5.7 ℃ higher than that in the edge of city and suburban district.Urban heat island effect was very distinct.The land surface temperature of different land cover types had great discrepancies,which were urban built land,farm land,grass land,forest land and water from high to low in order.The land surface temperature can reach 14 ℃ between urban built land and water.There was evident negative relationship between land surface temperature and vegetation cover rate,the lower land cover rate was the main reason to urban heat island.