基于改进两步移动搜索法的合肥市中心城区综合公园可达性评价

Accessibility evaluation of comprehensive parks in central urban area of Hefei City based on improved two-step floating catchment area method

为提高城市综合公园布局均衡性地定量评估的准确性,以合肥市中心城区为例,提出一种基于改进多出行模式的两步移动搜索法,利用高德地图的路径规划模型,结合双变量局部空间自相关、洛伦兹曲线以及基尼系数等方法,在手机信令数据的基础上对不同时间阈值下的城市综合公园的可达性及供需情况进行分析,进一步揭示中心城区综合公园布局的合理性。结果显示:合肥市中心城区综合公园的可达性空间差异显著,可达性较高区域通常分布在新城区以及综合公园周边地区,并且随着时间阈值的提高,可达性水平的空间分布呈现均衡态势;合肥市中心城区在15 min与30 min时间阈值下均只有近5%的居住网格处于供需匹配状态;近7%的居住网格处于供需显著不匹配状态,主要集中于老城区西部以及滨湖区北部区域,居住区密度与综合公园数量是影响供需匹配的重要原因。研究结果表明,通过利用手机信令数据与高德路径规划数据作为数据源对传统可达性的计算方法以及两步移动搜索模型进行改进,建立微观尺度下城市综合公园的可达性评价框架,能够精确地评估城市综合公园的可达性;通过优化城市交通的通达程度以提高居民综合公园游憩出行的阈值,能够显著促进城市综合公园整体的空间分布合理性。

A reasonable layout of urban park green space(UGS)is an important prerequisite for ensuring equal access to green space resources for urban residents and improving the living level of the city.In traditional UGS planning,the evaluation of urban comprehensive park services based on indicators including green space rate or green coverage rate is difficult to accurately and quantitatively evaluate the balance of the layout of urban comprehensive park.A two-step floating catchment area method based on improved multi-transport mode was proposed for the central urban area of Hefei City.The path planning model of Gaode map,combined with the methods of bivariate local spatial autocorrelation,Lorenz curve and Gini coefficient was used to analyze the accessibility and supply and demand of urban comprehensive parks under different time thresholds based on the signaling data of mobile phone.The rationality of the layout of comprehensive parks in the central urban area was further revealed.The results showed that the traditional method of calculating the accessibility and two-step mobile search model was improved by utilizing the signaling data of mobile phone and the path planning data of Gaode map as data sources.The accessibility evaluation framework of urban comprehensive parks at a micro scale was established,which can accurately evaluate the accessibility of urban comprehensive parks.The accessibility of comprehensive parks in the central urban area of Hefei City is significantly different in space.The areas with high accessibility are usually distributed in the new urban area and the surrounding areas of the comprehensive parks.With the increase of time threshold,the spatial distribution of accessibility level presents a balanced trend.Only about 5%of the residential grids in the central urban area of Hefei City are in the state of supply and demand matching under the time threshold of 15 minutes and 30 minutes.Nearly 7%of the residential grids are in a significant mismatch between supply and demand,mainly concentrated in the western part of the old city and the northern part of lakeside area.It is indicated that the density of residential areas and the number of comprehensive parks is important factors that affect the matching of supply and demand.Optimizing the accessibility of urban transportation to increase the threshold for recreational travel in comprehensive parks in residential areas can significantly promote the overall rationality of the spatial distribution of urban comprehensive parks.It will provide important guidance for optimizing the layout of comprehensive parks in the central urban area of Hefei City in the future.