长春市城区热岛效应遥感分析

Remote sensing analysis of heat island effect in Changchun city

针对城市热岛效应对城市生态环境产生的诸多问题,该文以长春市为研究区,利用Landsat TM/TIRS遥感影像,采用普适单通道算法反演地表温度,分析各种驱动因子对地表温度的影响。结果表明:普适单通道算法反演得到的地表温度与卫星过境时测得的气温差值在2℃内。高程(DEM)、优化土壤调节植被指数(OSAVI)、改进归一化差异水体指数(MNDWI)均与地表温度呈负相关,归一化差异不透水面指数(NDISI)与地表温度呈正相关,城市中心区地表温度相对高。长春市1995-2017年间各土地覆盖类型中水体变化最为稳定,裸地变化最为活跃;各土地覆盖类型的平均温度均呈现:建设用地>裸地>林地>水体。因此,通过增加植被与水域的覆盖范围、减少人为不透水面面积可缓解城市热岛效应。

Aiming at many problems caused by urban heat island effect on urban ecological environment,the current work took Changchun city as the study area,used Landsat TM/TIRS remote sensing images,retrieved the land surface temperature by using the single-channel method,and analyzed the influence of various driving factors on the land surface temperature.The results showed that the temperature difference was within 2℃ between the land surface temperature obtained via the retrieval of the single-channel method and the temperature measured when the satellite transits.Digital elevation model(DEM),optimization of soil-adjusted vegetation indices(OSAVI),and modified normalized difference water index(MNDWI)were negatively and normalized difference impervious surface index(NDISI)was positively correlated with the land surface temperatures,respectively.The development of social economy would lead to an increase in the land surface temperature.In the land cover types of the study area from 1995to 2017, the change of water body was most stable,and the change of bare land was most active;the average temperature of each land cover type followed the order of construction land>bare land>forest land>water body.Therefore,the urban heat island effect could be alleviated by increasing the coverage of vegetation and waters and/or reducing the area of ISA.