The Study Of Urban Heat Island Effect About The City Of Nanchang Using Landsat Data

This paper is based on the theory and technology of remote sensing and the heat island effect at home and abroad,used the series of Landsat images and calculated MNDWI、NDBI、NDVI,inverted the images of Nanchang by Atmospheric correction. And this paper analyse reasons for the spatio-temporal changes and affection of the layout of urban thermal environment.Using example based feature extraction to classify the land-use in Nanchang and analyze the impact of the change of land use on the urban heat island and the relationship between those two through the tool of spatial overlay analysis of Arc GIS10.1. Especially using the buffer analysis to analyse the influence of green land and wetland park on land temperature.The main content and innovations in this paper as follows:(1)The city of Nanchang has obvious phenomenon of urban heat effect,and it indicates that a trend of increase of surface temperature.The urban heat effect appear on the municipal district of Nanchang.From 2000 to 2014,the scale of extremely high temperature area and higher temperature area is decrease,but at the same time,the scale of middle temperature,less low temperature,low temperature and extremely low temperature area is decrease.The scale of less high temperature area is increase.Next,Nanchang only has obvious phenomenon of urban heat effect in summer and autumn.In spring and winter,the range of urban heat effect is very small.(2)The expending city leads to the increase in land temperature.From 2000 to 2014,the area of arable land and vegetation is decreased.And all of these decreased parts transform into the area of the built land.The temperature of the built land is the highest in seven kinds of land,which cause a expansion to the urban heat effect of Nanchang.(3)The degree of urban heat effect and man-made land surface was positively correlated,but has negative correlation with natural land surface.The profile analysis shows that water and vegetation coverage have the ability of cool the surrounding temperatures.The distance to the water and vegetation more far,the temperature of land surface lower.Protecting the vegetation and water and increasing the area of urban vegetation is a good way to remit urban heat effect.