Study On The Relationship Between Land Use/Cover Change And Heat Island Effect

The study of urban heat island effect has been paid more attention since the concept of urban heat island effect was put forward for the first time.At present,not only is the problem of urban heat island effect hot spot of academic research,but also the first problem needs to be considered which constructs the urbanization.Nanchang is the capital city of Jiangxi Province.In recent years,the pace of urbanization has been accelerated,the urban construction land area has been expanding,the land use and cover types have changed greatly,which lead to the urban heat island effect has become more and more serious and many ecological problems are coming.Based on this,the paper gives an analysis of the land surface temperature distribution of the different times of each country in Nanchang by atmospheric correction method inversion the land surface temperature in Nanchang City,using the 2000,2005 and 2009 Landsat-5 TM and 2014,2016 Landsat-8 OLI image data.At the same time,according to the outcome of land use type of Nanchang,which explores the correlationship of bare land,urban construction land,green land,water and land surface temperature.And extract indexes of normalized difference vegetation index,the normalized difference construction index and normalized difference water index in study area,by constructing the linear regression equation of each indexes and land surface temperature,giving an quantitative analysis of each index and land surface temperature.The results show that:(1)From 2000 to 2014,the land surface temperature of Nanchang has been increasing,and the temperature of Nanchang city center is obviously higher than other counties.According to the mean-standard deviation method,The results show that the heat island effect of Nanchang is gradually increasing,which is mainly extended from the center of the city to other areas such as Xinjian County and Jinxian County.And the intensity of the heat island effect is different in different seasons.The seasonal heat island effect in Nanchang is mainly the strongest in autumn,followed by summer and spring,and the weakest in winter.(2)In the process of urbanization development,the land use type of Nanchang has changed greatly,mainly due to the significant reduction of urban green space and water area,and the expansion of urban construction land and bare land area is obvious,and their increase mainly comes from the green area cut back(3)In the city,the average value of the construction land is the highest,followed by bare land and green land,the lowest land surface temperature is water.And the construction land and bare land and the growth trend of the land surface temperature is consistent,the green space,water and then showed a reverse growth trend.(4)There is a significant correlation between each normalized difference index and land surface temperature.Among them,NDVI and NDWI showed a significant negative correlation with land surface temperature,and the negative correlation between NDWI and land surface temperature was higher than NDVI.NDBI and land surface temperature showed significant positive correlation.That is to say,in the city the construction land and bare land on the surface of the heating effect of the greatest contribution,and green space and water has a strong cooling effect on surface temperature,and the cooling effect of water is better than green.