基于改进引力模型的公园绿地空间可达性及供需平衡分析方法

探究高密度城市公园绿地资源空间配置的有效性和供需平衡问题对城市规划和居民生活具有重要意义。已有研究较少从多尺度、多交通出行模式以及结合地图大数据算法的角度对公园绿地可达性进行探究。本文以广州市越秀区为例,利用百度地图多交通出行数据,提出一种结合多类型公园绿地多级可达时间阈值的改进型引力模型,对越秀区公园绿地的空间可达性及其供需平衡特征进行研究。结果表明：① 越秀区各尺度和各类型公园绿地可达性差异显著,城区尺度可达性大体上呈现由北向南逐层递减趋势,街道尺度可达性则表现出明显的“极化”现象,大型公园绿地可达性远高于社区公园和街头游园且在城市整体可达性中占主体地位;② 从空间集聚情况来看,城区尺度公园绿地可达性值呈现明显的空间集聚分布特征,由北向南表现为高值聚类、不显著、低值聚类,街道尺度相比城区尺度高值聚类减少,低值聚类和无统计意义的区域增多;③ 基于供需平衡视角的空间可达性结果显示,公园绿地供给与居民需求在城区尺度和街道尺度分别呈现出整体平衡和局部失衡的现象,局部失衡主要集中在公园绿地资源相对匮乏的街道。

Spatial Accessibility and Supply-demand Balance Analysis Method of Park Green Space based on Modified Gravity Model

Exploring the effectiveness of the spatial allocation of park green space resources and the balance of supply and demand is of great significance for urban planning and residents' life in high density cities. Previous studies have rarely explored the accessibility of park green space from the perspectives of multi-scale, multi-traffic travel modes, and combination with big data algorithms. Therefore, the paper proposed an improved gravity model that combines multi-type park green space and multi-level travel time thresholds based on the multi-traffic travel data obtained from Baidu Map, and analyzed the spatial accessibility of park green space and the characteristics of the balance between supply and demand in Yuexiu District of Guangzhou City. The results show that: (1) There are significant differences in the accessibility of multi-scale and multi-type parks in Yuexiu District. The district scale accessibility generally shows a decreasing trend from north to south, and the subdistrict scale accessibility shows obvious "polarization" phenomenon. The accessibility of large parks is much higher than that of community parks and street gardens, which occupies a dominant position in the overall accessibility of the city; (2) In terms of spatial aggregation, the accessibility of district scale park green space shows obvious spatial aggregation and stratification, with high-value clustering, insignificant, low-value clustering from the north to south. Compared to the district scale, the subdistrict scale has fewer high-value clusters, and low-value clusters and non-statistically significant areas have increased; (3) The spatial accessibility results based on the perspective of supply and demand balance show that there is overall balance and local imbalance between the supply of park green space and the demand of residents in Yuexiu District. The local imbalance is mainly concentrated in areas with dense residential areas and relatively sparse park green space resources.