城市绿色空间可达性与居民分布的空间匹配与影响因素

城市居民的绿色空间可达性是衡量城市基础设施公平分配的指向标，关乎城市民生福祉。以宁波为研究区，基于高德地图路径规划Application Programming Interface（API）测度了绿色空间可达性，融合多源数据模拟了人口空间分布，分析了绿色空间可达性与人口分布的空间匹配状态，并采用地理探测器探讨其影响因素。研究表明：①宁波绿色空间可达性由各区中心向郊区衰减，高可达性空间占比不高，反映了绿色服务供给不足的现状。高可达性空间集中于三江口、鄞州新城、北仑城区和镇海老城区，低可达性空间则主要分布在东部郊区、西部山区和南部农业区。②宁波居民的绿色空间可达性在空间上表现为市中心高人口密度—高可达性和郊区低人口密度—低可达性的空间匹配特征，在规模上仅不及半数的居民享有15min绿色空间可达性，在乡镇尺度上呈现显著的城区—郊区二元类型分异。③城市居民绿色空间可达性受多重影响因子驱动，按照重要性依次为区位特征、人类活动、开发强度、社会经济和地形条件。

Spatial match between urban residents' distribution and green space accessibility and its driving force

The accessibility of urban residents to green spaces is not only an essential indicator of equitable distribution of urban infrastructure but also a basic component to build livable city, which is linked with urban resident''s well-being. In this study, taking Ningbo urban area as a case, we calculated the accessibility of urban green space using the Amap route planning Application Programming Interface. We also simulated the spatial distribution of urban resident based on multi-source data, including land use, nightlight, Normalized Difference Vegetation Index (NDVI), Point of Interest (POI), and road network. The spatial match between green space accessibility and urban residents'' distribution was thus analyzed on the grid scale with a resolution of 100 m. Furthermore, the drivers for the accessibility of urban residents to green spaces was explored using the GeoDetector. The results show that the accessibility of green space in Ningbo is descending from each district''s downtown to peripheral area, with a large proportion of poor accessibility coverage, indicating the weak green service on the whole. The area with good accessibility to green space is concentrated in the confluence of Yao River, Fenghua River and Yong River, Yinzhou new city, Beilun downtown, and Zhenhai old urban area, while the area with poor accessibility is distributed in the eastern and western mountainous area and the southern agricultural region. The accessibility of urban residents to green spaces in Ningbo shows two characteristics:high-density population and good green space accessibility in the downtown and low-density population and poor green space accessibility in the urban periphery. Also, it tends to evolve into an urban-rural dual structure at sub-district scale, which can be classified as three types including downtown, urban periphery, and industrial cluster/agricultural region/ecological conservation area. The proportion of urban residents living with green space accessibility within 15 min is less than 50%, reflecting the limited green service for urban residents in Ningbo. The drivers for the accessibility of urban residents to green spaces analyzed by the GeoDector show that five indicators as proxies for drivers are both significant. The ranking of drivers for the accessibility of urban residents to green spaces is location, human activity, development intensity, social economy, and terrain condition.