Analysis Of Three Dimensional Urban Heat Island Effect

With the rapid development of economy,the arrival of the era of global big data,accelerate the process of city construction,frequent human activities,so that the original green vegetation,agricultural land was replaced by the buildings and roads,even the mountain was also dug Ping as the development of city land.This series of activities changed the structure of the underlying surface of the city,so that the original thermal properties have undergone tremendous changes,thus affecting the ecological environment of the whole city.As a famous tourist attraction,Guilin has become the most suitable city for human habitation because of its unique geological features and excellent ecological environment.Therefore,under the background of increasingly bad greenhouse effect,how to maintain a good ecological environment in Guilin has become an important factor affecting the future development of Guilin.Therefore,it is necessary to study the structural characteristics of heat island effect in Guilin.In this paper,the ground observation method,thermal infrared remote sensing technology and the establishment of DEM elevation model are combined.The thermal infrared remote sensing method is used to study the three-dimensional thermal environment of Guilin city.It can be through the previous research,by 2006,2010 and 2016 three different years in the same season,Landsat5 Landsat 8 remote sensing images,the image data acquired and DEM SRTM3 elevation data were preprocessed by ENVI5.1 remote sensing image processing software,the image data from different remote sensing satellite sensors the selection of atmospheric correction method to calculate the surface temperature.The surface temperature results were divided into low density separation,extremely high temperature zone and high temperature zone,intermediate zone and low temperature area,while the area,normalized income segmentation density corresponding,divided into strong heat island area,island area,middle area,green area and strong green area.The 3D normalized thermal field effect distribution map is obtained by performing the corresponding data fusion with the 3D image,so that the distribution characteristics of thermal environment can be analyzed.Using the landscape pattern analysis software Fragstats3.3,the 5 thermal landscapes are analyzed,which reveals the change law of the land surface temperature under the different elevation difference.The main conclusions of this study are as follows:(1)Guilin City area has obvious regional thermal environment,high temperature and concentrated in the Lijiang River basin center based in densely populated areas,low-lying areas,surrounded by mountains,the rest of the relatively high elevation area temperature did not change significantly.This shows that,for mountainous areas,ground elevation differences really affect the formation of thermal environment.(2)Through the analysis of the thermal landscape type can get the change regularity of Guilin city thermal environment,indicates that with the passage of time and the height difference,change of thermal landscape pattern obviously prominent,strong heat island areafragmentation is still high,and the green zone and the middle zone fragmentation degree is relatively low.(3)There is a negative correlation between urban heat island effect and ground elevation.The higher the elevation and the lower the temperature,the higher the fragmentation degree of the thermal landscape,the lower the temperature in the plain low-lying area and the lower fragmentation of the thermal landscape.At the same time,changes in topography and topography also have a certain impact on the thermal environment.(4)Within the city water,wetland park,green space,as an important means to alleviate the thermal environment of the region,with reasonable planning and construction of city,scattered population,ecological city building a green and harmonious,helps to reduce urban heat island effect.