基于MODIS影像的沈阳城市热岛效应及其与植被指数的关系研究

Study on the Relation Between Urban Heat Island Effect and Vegetation Cover Index Using MODIS Image

采用2001年和2008年沈阳MODIS遥感影像,运用分裂窗算法反演沈阳地表温度,并以郊区平均地表温度为准,将沈阳市辖区的温度划分为4级,研究沈阳城市热岛效应的空间变化特征,并分析了城市热岛强度与NDVI之间的关系。结果表明:沈阳存在明显的热岛效应,总体呈现由市中心向外逐渐扩张的空间特征。与2001年相比,2008年城市热岛范围明显扩大,2级弱热岛效应区的面积明显增加,增加129km2,3级和4级热岛效应区的面积增加相对较少,但1级非热岛效应区却急剧减少,减少857km2。城市热岛效应和NDVI之间存在极显著的负相关关系,植被对减缓城市热岛强度有着积极的作用。

Based on MODIS images of Shenyang in 2001 and 2008,land surface temperature was retrieved with split window algorithm,average surface temperature was valid.The Shenyang municipal districts of temperature was divided into four study,study spatial variation of urban heat island effect in Shenyang,and analysis relationships between urban heat island intensity and NDVI.The results showed that：（1） It has obvious heat island effect in Shenyang,showing an overall gradual expansion outward from the center of the spatial characteristics.Compared with 2001,urban heat island significantly expanded in 2008,the areas of increase two grade weak heat island effect increased significantly（129km2）,the areas of 3 and 4 grade heat island effect relatively smaller increased,but a non-heat island area dropped sharply（reducing 857km2）.（2） NDVI and urban heat island effect has significantly negative correlations,vegetation play a positive role in mitigating urban heat island intensity.