基于改进两步移动搜索法的上海市黄浦区公园绿地空间可达性分析

为解决高密度城市公园绿地供需不平衡的问题,论文提出了一套改进的两步移动搜索模型,并以上海市黄浦区为例,对其现有公园绿地进行步行条件下的空间可达性分析。首先从网络爬取研究范围内居住小区POI信息,将其聚合在边长100 m的正六边形蜂窝网内,计算得到每个人口单元的人数及人口密度,并利用百度地图API路径规划接口爬取各供给点和需求点间基于实时路况的出行时间;其次,以黄浦区2019年底已建公园绿地为例,从居住区人口需求、可达性分级、冷热点和盲区分析4个方面对其供需配置进行量化分析,结果表明,黄浦区公园绿地可达性水平整体北高南低,和人口密度分布呈负相关,存在供需错位问题,且仍有9.16%的显性盲区和16.5%的隐性盲区亟待消除。研究结果为进一步优化绿地空间布局和选址提供指导依据;最后从适度增量、盘活存量、社区共治3个方面提出建议,以期为黄浦区绿化“十四五”规划提供理论支持。

Spatial accessibility of park green space in Huangpu District of Shanghai based on modified two-step floating catchment area method

In order to solve the problem of unbalanced supply and demand of park green space in high density cities, this study used a Gaussian based two-step floating catchment area method to analyze the spatial accessibility of existing park green space in Huangpu District of Shanghai, under walking conditions. First, we extracted the point of interest (POI) data of residential areas from the Internet and aggregated them into a 100 m long hexagonal cellular network to calculate the number of people and population density, then through the Application Programming Interface (API) of Baidu Map we extracted the travel time between supply and demand points based on actual road conditions. Second, the paper took the park green space built by the end of 2018 in Huangpu District of Shanghai as an example, and considered the four aspects of residents' demand, accessibility classification, cold and hot spots, and blank areas. The results show that the accessibility level of park green space in Huangpu District is higher in the north and lower in the south, which is negatively correlated with the population density distribution. The dominant blind areas (9.16% of the total area) and the recessive blind areas (16.5% of the total area) should be eliminated. This study made a quantitative analysis on the supply and demand allocation, to provide guidance for the further optimization of green space layout and site selection. Finally, recommendations were made from three aspects of "increasing green space appropriately", "strengthening the quality of existing green space" and "community co-governance", in order to provide theoretical support for the Fourteenth Five-Year Plan of greening Huangpu District.