存量更新背景下综合公园-周边社区步行可达性评估及微更新分析——以石家庄市长安公园为例

Evaluating Pedestrian Accessibility and Adaptive Retrofit for Comprehensive Parks and Surrounding Communities:An Existing Stock Based Case Study of Chang'an Park in Shijiazhuang City

城市中心区的综合公园是提升周边社区生活品质的关键场所,也是城市生态和文化基础设施的重要节点。步行可达性对综合公园的日常使用至关重要,也是理解其潜在供需及周边中小绿地级配合理性的途径之一。直观、尽量精确且顾及尺度层级的步行范围评估有助于理解公园-社区可达性,并为确定具体干预位置和策略提供参考。以石家庄市长安公园为例,首先使用泰森多边形工具划分综合公园就近服务范围,然后抓取范围内所有住宅建筑至综合公园入口的百度地图规划路径,并根据不同距离阈值划分步行范围,发现综合公园周边的社区之间存在显著的空间差异。研究结果表明:在距离长安公园1 500m步行范围内,居民人口达14.28万人,占长安公园就近服务范围居民总人口的65.7%;周边中小绿地可以补偿服务4.58万人,但仍有2.88万居民位于合理的步行距离外。建议结合微更新理念,增设或调整公园和小区入口等以扩大现有综合公园的有效服务范围,在服务盲区内增建中小绿地以增加受惠居民的数量。

The comprehensive parks,particularly those near the city center,play irreplaceable roles as vital nodes of the ecological and cultural infrastructure,as well as an amenity for the surrounding residents.Convenient walking to the park is crucial for their frequent park visits,which provides a lens of understanding the potential supply-demand and rationalizing the hierarchy of various-sized green spaces nearby.In this study,an intuitive yet subjectively accurate,multiple-scale bridging approach is proposed to delineate pedestrian catchments,measure the park-community accessibility and specify the intervention location and tactics.The approach was explored and validated in a comprehensive park-Chang'an Park-in Shijiazhuang.Thiessen polygons were used to estimate the nearby service area of the comprehensive park as the first step.Subsequently,all residential buildings within the area and the relevant walking routes to the entrance of the comprehensive park were extracted from Baidu Maps with Python coding.Then,pedestrian catchments were delineated at different distance thresholds,revealing significant spatial disparities in the park's surrounding communities.Within a 1,500m walking distance from the park's entrances,the resident population reaches 142,800,accounting for 65.7%of that within the park's nearby service area.In the same area,the surrounding small green spaces can serve 45,800 people,yet there are still 28,800 residents located beyond a reasonable walking distance.Therefore,the adaptive retrofit by adding entrances of the park and communities at specific locations,and building small green spaces in the areas lack green space,etc.,is proposed.If implemented,these interventions would improve the residents'access to the green space,as demonstrated by the scenarios.