城市地域地表温度与土地覆盖定量关系分析

利用Landsat TM影像,以合肥市区为研究区,采用最大似然法对合肥市影像进行土地覆盖分类,同时反演合肥市地表温度,然后计算NDVI(归一化差异植被指数)、MNDWI(改进的归一化差异水体指数)、NDBI(归一化差异建筑指数)和NDBaI(归一化差异裸土指数)4种指数.在此基础上,对合肥市城市热岛的空间分布特征、地表温度与土地覆盖类型以及各种影响因子之间的关系进行定量研究分析.结果表明,不同土地覆盖类型的地表温度存在较大差异,建筑用地和裸地是城市热岛强度的主要贡献因素,植被和水体具有较好的降温作用.地表温度与4种归一化指数的回归分析表明,它们之间存在明显的相关性.

The Quantitative Relationship between Land Surface Temperature and Land Cover Types Based on Remotely Sensed Data in Hefei City

Taking Hefei city as the case study area,The land cover types were classified in the study area by maximum likelihood method,and the land surface temperature(LST)was retrieved using Landsat TM data,then,NDVI,MNDWI,NDBI and NDBaI indices were calculated.On this basis,the spatial distribution characteristic of Urban Heat Island(UHI)in the study area and the relationship between LST and land cover types and various affecting factors were studied quantitatively. The research results show that the LST in different land cover types was remarkably different.The built-up area and barren land seem to be the major factors responsible for UHI intension,while the vegetation and the water body play an important role in reducing LST.Regression analysis shows that there exists a significant correlation between LST and the four indices.