Influence Of Urban Spatial Structure On Urban Thermal Environment Effect Of Beijing

In recent years, China’s urbanization process is accelerating, the social economy is therefore developing rapidly, but it also leads to many problems:the urban scale continues to expand, urban spatial structure is irrational, a waste of energy resources and environmental pollution etc.In many factors that affect urban environmental quality, urban thermal environment is an important factor affecting the quality of urban environment, the influence of urban spatial structure on urban thermal environment is also increasingly concerned. This research based on the Landsat series remote sensing image as basic data, combined with high resolution remote sensing image and land use data, and analyzed the relationship between urban spatial structure and urban thermal environment from three aspects of Beijing urban building density structure, the structure of urban green space and urban expansionThe results show that the main building density regions are the medium density building regions within the fifth highway ring in Beijing. The distribution of high density building regions is slightly less than that of medium density building regions. There are great differences between the distribution of different building density regions between different highway rings. The relationship between land surface temperature and building density in urban building regions is significantly positive, the greater the density of urban buildings, the higher the average land surface temperature. From the aspect of the change of heat island intensity during 2010-2015, in general, only the tendency of heat island intensity in the high-rise building regions is weakened. While the tendency of heat island intensity in high, medium and low density building regions are enhanced, and the increase of heat island intensity in high density regions is the largest. Base on many researches, appropriately reducing the density of urban building can effectively ease the urban heat island effect.The landscape composition of urban parks has a significant impact on its internal temperature. The average temperature of the urban parks is mainly affected by water body area and the proportion of ground constructions. Properly increasing the area of water surface, reducing the proportion of the construction area can effectively reduce the internal temperature of the urban park. The cooling effect of urban parks is affected significantly by its morphological characteristics and spatial pattern. Urban parks have obvious cooling effect on their surrounding thermal environment. The cooling range of selected urban park is between 389.27-2905.18m, among them the largest cooling rate is 7.48℃ of the Summer Palace. To improve the overall thermal environment of the city, the internal landscape composition needs to be improved.Beijing is in the process of rapid expansion, new urban construction land expand on both sides of the north and south direction along the east-west axis. The expansion of main urban region of Beijing is northward based on the original urban, and the expansion of Miyun, Huairou and Shunyi District is more obvious. From the view of the distribution of temperature, high temperature regions is mainly concentrated in the main urban, and the area showed a trend of sustained growth in 2005-2013. The distribution of the middle temperature regions in 2005-2013 is shown as the trend of continuous reduction. The contribution of urban land to surface thermal effect is the largest, and the contribution of water to the surface thermal effect is the least. The trend of the center of gravity of the high temperature regions is consistent with that of the center of gravity of urban land, proving that urban expansion is an important factor which leads to the change of surface thermal environment in Beijing. Rational allocation of urban spatial structure and rational planning of urban development is the foundation of urban sustainable development.