Study On The Status Quo Of Heat Island Effect And Greenbelt Reduction Effect In Taiyuan City

With the development of China's economy and society,urbanization has been continuously strengthened,cities have been expanding,urban energy consumption has increased,and more artificial heat has been released.In addition,due to the increase of new high-rise buildings,a large amount of heat is accumulated in the urban area,which is not easy to spread,which further aggravates the heat island effect in the built-up area.Solving the urban thermal environment problem has become an urgent task,so based on the remote sensing image data,combined with the boundary change range of the sixth phase of Taiyuan 's built-up area,the thermal environment status of Taiyuan City and the thermal environment pattern of Taiyuan City in the past 20 years have been studied;In the past 20 years,the spatial pattern of green space in Taiyuan has changed;qualitative and quantitative analysis of the reduction of green land on heat islands,changes in park green space and its cooling effect.The research results are as follows:(1)Based on the changes in the built-up area of Taiyuan City in the past 20 years,the establishment of a buffer zone around the built-up area proves that there is a heat island effect in the built-up area of Taiyuan City,and the quadrant analysis method proves that the center of gravity of the urban heat island is consistent with the direction of urban expansion.The urban thermal environment in Taiyuan City gradually deteriorated from 1999 to 2014,and the urban thermal environment improved from 2014 to 2018.The range of heat island distribution changes with the type of urban land use cover.The temperature of unused land and construction land is higher,and the temperature of vegetation and water area is lower.(2)In the past 20 years,the number of green patches in Taiyuan City has been statistically compared by quadrant analysis,and the number of patches in the northwest quadrant has decreased first and then increased.The number of patches in the northeast quadrant has increased first and then decreased.The southeast quadrants showed a trend of decreasing first and then increasing.The comparison between the surface temperature and the normalized vegetation index map shows that the two have opposite trends.The higher the normalized vegetation index,the lower the surface temperature.Further quantitative analysis of the negative correlation between normalized vegetation index and surface temperature.The landscape analysis pattern software calculates the green space index that affects the surface temperature and finds that the patch density,the positive difference of the patch surface and the surface temperature have a strong correlation,both of which fall within a certain range as the index increases.(3)In the past 20 years,the number of parks in Taiyuan City and the overall coverage of park vegetation have increased.By analyzing the morphological characteristics of the park,it is concluded that the larger the area and perimeter of the park,the lower the average temperature inside the park,and as the shape index increases,the average temperature inside the park also increases.By analyzing the internal composition of the park,it is concluded that the vegetation and water area have a better cooling effect on the average surface temperature inside the park.By comparing the cooling range of the park's green space,it is found that the cooling effect becomes worse and worse as the distance from the park increases,and the cooling effect over a certain range will no longer be obvious.