Urban Health Spaces Recognition And Its Impact On Vulnerable Groups Based On Walkability And PM2.5 Exposure

Urban public health has become one of the important issues for sustainable urban development in the world.Health is not only related to physical activity obtained by residents during their daily travel,but also affected by external environment such as air pollution.While emphasizing the improvement of walkability to increase residents’outdoor physical activity,ignoring the risk of pollutant exposure is doubtful for improving residents’health.The identification of urban health space with high walkability and low PM2.5 exposure can help residents improve their awareness of health risks and safety and better avoid unhealthy space.This study took the main urban area of Wuhan City as the research area,used the walkability evaluation model and land use regression model to evaluate the walkability status and PM2.5 exposure based on multi-source data.Combined with the results of walkability and PM2.5 exposure,the urban space was classified and identified to find out the urban health space with high walkability and low PM2.5 exposure.Based on the comparison of distribution characteristics of various health spaces in age structure,this paper explored the influence of various health spaces in Wuhan City on vulnerable groups,and put forward corresponding suggestions.Main findings included:(1)The average walk score in Wuhan City was 73.23,and the walkability was good on the whole.The average walking index in the main urban area of Wuhan City is 73.23,and the walkability is better.At multiple scales,walkability was distributed in circles,and the walk score gradually decreased from the city center to the periphery.Specifically,at the whole scale,65.05%of the areas with walk score greater than 70was distributed in Hankou and Wuchang areas.The area with poor walkability accounted for 13.32%,mainly distributed in the periphery.At the ring road scale,the average walk scores of the inner and second ring areas were greater than 85,and the walkability of the areas outside the third and third rings were significantly reduced.At the district scale,Jianghan District had the best walkability,with an average walk score of 91.02;the walkability of Qingshan District,Wuhan Economic and Technological Development Zone were general,with the average walk scores below 70.At the street scale,31.91%of the streets had an average walk score higher than 90,which were mostly distributed in the city center.15.96%of the streets with an average walk score below 70 were distributed in the outskirts of the main urban area.(2)The average PM2.5 concentration in Wuhan City was 95.61μg/m~3 and the overall PM2.5 exposure risk was relatively high.At multiple scales,the exposure risk of PM2.5showed a trend of high in the west and low in the east,low in the periphery of the Yangtze River and East Lake,and high in Hankou and Hanyang areas.At the whole scale,only 34%of regions had a PM2.5 concentration lower than 95.13μg/m~3,and the rest of the regions were at high or severe risk of PM2.5 exposure.At the district scale,Jianghan District has the most serious PM2.5 exposure risk,with an average PM2.5concentration of 99.49μg/m~3,followed by Hanyang District and Qiaokou District.The PM2.5 exposure risk of East Lake Scenic Area of Wuhan was the lowest,with an average PM2.5 concentration of 91.10μg/m~3.At the street scale,the PM2.5concentration in 23 streets was lower than 95.05μg/m~3,and most of them were adjacent to the Yangtze River and East Lake,with a low risk of PM2.5 exposure.The 21 streets faced serious PM2.5 exposure risks,with an average PM2.5 concentration greater than98.52μg/m~3,mainly distributed in areas north of the Yangtze River and industrial areas in the northeast,covering a wide area.(3)In Wuhan City,health space with high walkability and low PM2.5 exposure accounted for 25.65%of the total area,covering 32 streets,mainly distributed along the Yangtze River and south of the Yangtze River,showing a trend of more in the east and less in the west.The proportion of non-health space with low walkability and high PM2.5 exposure was 20.54%,covering 11 streets and mainly distributed in industrial areas outside the main urban area.In addition,there were 39.17%spaces with high walkability and high PM2.5 exposure in Wuhan City.In these areas,emphasizing one-sidedly on increased walking was associated with health risks.The population coverage of different types of health space was significantly different in Wuhan City.More than40%of the population was distributed in healthy space,while less than 10%of the population was distributed in non-healthy space.From the perspective of age structure,healthy space and non-healthy space had no obvious tendency to vulnerable groups.Children faced more serious environmental health problems than the elderly.From this,policy suggestions were put forward:optimizing the stock land to improve the allocation of daily living service facilities;increasing PM2.5 pollution control measures to improve air quality;rationally arranging urban green space and daily living service facilities;and continuing to pay attention to the differentiation of living space suitable for people of child-bearing age and children.