南昌市城市不透水面及其与城市热岛的关系分析

Analysis on the Relationship between Impervious Surface Area and Urban Heat Island in Nanchang City

通过分析南昌市不透水面和城市热岛的相关关系从而为缓解城市热岛效应提供技术指导.以南昌市2002年、2014年Landsat TM/TIRS遥感影像作为数据源.采用改进的归一化水体指数(modified normalized difference water index,MNDWI)进行水体的提取,结合归一化差值不透水面指数法(normalized difference impervious surface index,NDISI)对南昌市不透水面信息进行提取,然后采用单窗算法进行温度反演.分析比较2个时期的不透水面分布图和地表温度分布图,在2002-2014年间,南昌市不透水面面积与高温分布面积都明显增加,且主要是沿赣江两岸扩张.而从二者的线性回归方程式中可以看到,它们之间存在着显著的正相关性,这说明城市不透水面面积的增加会加剧城市热岛效应.

By analyzing the relationship between the impervious surface and urban heat island of Nan-chang City so as to provide technical guidance for relieving urban heat island effect. Taking the Landsat TM/TIRS remote sensing image of Nanchang City in 2002 and 2014,as the data source.The modified nor-malized difference water index （ MNDWI） was used to extracted water and normalized difference impervi-ous surface index （ NDISI） was used to extract the impervious surface information,then the single window algorithm was used for temperature inversion.The impervious surface distribution and surface temperature distribution of the two periods were analyzed and compared.The result shows that,the impervious surface area and high temperature area significantly increased during the period of 2002-2014 in Nanchang City, and they mainly expanded along the both sides of the Ganjiang River. It can be seen from the linear re-gression equations of the two distribution diagrams that there is a significant positive correlation between them,which indicates that the city impervious surface area increases will increase urban heat island effect.