Urban Heat Vulnerability Assessment From The Perspective Of Living And Working Function

Global climate change and rapid urbanization aggravate the frequency of extreme events.Heat wave,as a typical effect,poses a great threat to urban ecological environment and residents' health.As the risk of urban thermal risk is not evenly distributed,it is necessary to study the differences of human activities and functional types in the city,which is of great significance to improve the accuracy of assessment and guide the practice of differentiation.Taking Beijing as an example,based on the combination of POI data and mobile location data to divide urban functional areas,this paper identifies the residential,industrial and office functions that are most closely related to human activities from the perspective of living and working function.Based on the theoretical system of vulnerability assessment,through the framework of ‘exposure-sensitivity-adaptability',the assessment indexes are constructed according to the difference of each function.The weight of the indexes under the three functions is determined by AHP and entropy weight method,and the vulnerability index is calculated.Statistical analysis and spatial analysis are used to identify the high exposure,high sensitivity,low adaptability and high heat in residential,industrial and office functions The main conclusions are as follows:(1)The high thermal vulnerability area of residential function is far away from the urban center,mainly located in the new urban development area and ecological conservation development area.High exposure areas are more concentrated in the functional development areas around the city center and scattered in the new urban development area;high sensitivity areas are distributed in the areas with high population density,such as Xicheng,Haidian,Chaoyang,Fengtai and Changping,and low adaptability is located in the most peripheral areas of Beijing.(2)The high heat vulnerability area of industrial function is located in Tongzhou and Fangshan District of Beijing New Urban Development Zone.Through the verification and analysis of remote sensing base map,it can be seen that there are a large number of bare land,clothing factory with blue steel roof,industrial park and logistics area around the high thermal vulnerability area of industrial function,high surface temperature,densely populated villages nearby,low overall economic level,lack of green vegetation and medical facilities coverage.High exposure and high sensitivity areas are scattered in new urban development areas and functional development areas;low adaptability areas are scattered in Tongzhou and Fangshan areas of Beijing new urban functional areas.(3)In the office function,the high heat vulnerability area is mainly distributed in the ecological conservation area and the new urban development area.The urban functional core area and the functional expansion area in the urban center are high exposure,high sensitivity and high adaptability areas,and the low adaptability mainly exists in the peripheral areas of Beijing.(4)From the perspective of comprehensive residential,industrial and office functions,the high-temperature vulnerability is mainly distributed in the new urban development zone,with high-tech industry and manufacturing industry as the main industries,carrying the role of evacuating the city's central population and industry;the second is the Ecological Conservation Development Zone in the outskirts of Beijing,where human activities are relatively small,with agriculture and leisure tourism industry as the main industries and high green vegetation coverage,Medical resources are extremely scarce.High exposure and high sensitivity were in the central area of each functional range,and low adaptability was in the periphery.At the same time,the areas with high thermal vulnerability are all areas with high exposure,high sensitivity and low adaptability.Therefore,adaptability plays an important role in reducing the urban thermal vulnerability.At present,the central city gathers high-density public resources.The following resource layout of urban management,such as traditional Chinese medicine services,needs to be inclined to the most peripheral areas of Beijing.