基于TM数据的合肥市城市热岛效应研究

Research on the Urban Heat Island Effect of Hefei Based on Landsat TM Data

城市热岛的空间分布与其下垫面环境极其相关。基于Landsat TM数据反演出合肥市市区地表温度;并分析合肥城市热岛分布、变化情况以及城市地表温度与其下垫面土地覆盖类型之间的关系。对合肥市市区2007年7月17日的地表温度分布图的分区统计显示出较大的温度差异:城镇用地具有高的平均温度(31.19℃),自然地表具有较低的平均温度(30.15℃),而水体的平均温度更低(26.88℃)。分别用%ISA(不透水面率)、NDVI值和MNDWI值来提取城市的不透水面、植被和水体信息;并对地表温度与%ISA、NDVI、MNDWI进行回归分析。结果表明,地表温度与%ISA和NDVI值有较好的相关性。

The Spatial distribution of urban heat island is closely related to city underlying surface. Land surface temperature of Hefei city was retrieved based on Landsat TM data,and the relationship between characteristic land uses and land surface temperature was analyzed. Zonal statistics on land surface temperature distribution image of Hefei on July 17 th 2007; revealed statistically significant differences between high average temperature for urban land use（ 31. 19 ℃）,and low average temperature for natural surfaces（ 30. 15 ℃） and water bodies（ 26. 88℃）. Furthermore,% ISA（ the percentage of impervious surface area）,NDVI value,MNDWI value was used to extract the impervious surface rates of city,vegetation and water,the relationship between land surface temperature and impervious surface rate,NDVI,MNDWI was analyzed by the regression analysis. Finally,some measures to help relieve the urban heat island effect for the future development of Hefei are put forward.