Research on the Spatial Effect of Urban Construction on Heat Island Effect in Shanghai Based on Remote Sensing Data

Since the twentieth Century,global urbanization process is constantly accelerating,while the landscape pattern dominated by vegetation was gradually replaced by the landscape pattern dominated by artificial buildings.The change of climate and temperature caused by the expansion of urban construction land and the population aggregation,has aroused widespread concern.Under the background of national new type urbanization,improving the urban environment is the inevitable path to the new type urbanization. Urban heat island effect is the most prominent feature of human activities impact on temperature,and it has many effects on environment,economy,society,health and so on. Among the existing researches related to urban heat island effect,the influence of urbanization on it has not been paid enough attention.Therefore, the research on the effect of urban construction on the heat island effect is incompletable,and the method is limited to the quantitative analysis as the spatial analysis is insufficient. Based on the existing research,while under the background of urban planning major,taking Shanghai as a typical case, this paper concentrates on the urban heat island effect under the influence of Shanghai urban construction. First of all,this paper takes the Landsat-7 ETM+ remote sensing image data of Shanghai in 01/08/2000,28/07/2010 and 28/07/2016 as the basic research data.ENVI software is used to retrieve land surface temperature on the thermal infrared band.Then this paper divides the heat island effect level,analyses the spatiotemporal distribution of land surface temperature in different years in Shanghai,and summarizes the evolution characteristics of urban heat island effect, analyzing the spatial impact of urban construction related factors such as urban scale, spatial structure and land use. Analysis shows that city construction land expansion will aggravate the urban heat island effect.The increment of built construction in the city,the size of the resident population,as well as the population density have significant correlation with urban heat island effect,but the spatial distribution of population density and spatial distribution of heat island effect has no significant correlation.In various types of landuse,residential,industrial and mining,warehousing, commercial services,and transportation land can significantly aggravate the heat island effect, land types like green land, water area and farmland,etc can produce urban cold island effect in some individual area.At the same time,the location, area and shape of the green space and water area have an effect on the distance of reducing the heat island effect.