重庆市主城区热岛效应与植被覆盖关系研究

摘要

为了研究重庆市主城区热岛效应与植被覆盖的关系，利用重庆市主城区2008年TM遥感数据，提取了NDVI(植被归一化)指数，并结合野外实地调查，获取了地表植被覆盖度数据，利用GIS空间分析技术及数理统计方法进行了分析。结果表明，重庆市主城区热岛效应明显，在空间上呈大片、连续分布状态；热岛效应与植被覆盖度呈负相关关系，即随着植被覆盖度的提高而降低，在植被覆盖度高于50%后热岛效应消失。城市绿地面积越大，内外温差也越大，从而形成热岛中的“冷岛”，城市绿地对热岛效应具有重要的减缓作用。%In order to study the relationship between urban heat island effect and vegetation cover in the core area of Chongqing City, the NDVI (Normalized Difference Vegetation Index) is extracted from TM images of the core area of the city in 2008, and the land surface’s vegetation cover data are obtained by field investigation. The relationship between vegetation cover and urban heat island effect was analyzed on the basis of GIS data and corresponding mathematical statistics. The analysis results show that the urban heat island effect in the city core area is very obvious, which extensively appears in a large and connected areas; the urban heat island effect is negatively interrelated with vegetation cover, it reduces with the increase of vegetation cover rate and disappears if the vegetation cover rate is greater than 50%. The bigger area of urban green space is, the bigger temperature differ-ence exists, thereby forming a"cool island" in the heat island. Therefore, the urban green space has an important role in mitiga-ting the urban heat island effect.