基于G2SFCA的武汉市中心城区公园绿地空间公平性分析

Spatial equity of public green in Wuhan central districts based on gravity two-step floating catchment area method

公园绿地空间布局和结构会影响到城市居民的健康和城市生态格局,对城市规划建设至关重要。因此,评价城市公园绿地的空间分布具有重要的现实指导意义。本文以武汉市七个中心城区为例,采用含有距离衰减系数的重力型两步移动搜索法(G2SFCA),探讨居住区尺度下不同等级公园绿地的空间公平性。结果表明:(1)距离因素会改变公园绿地的空间公平性,并且不同等级公园绿地的空间公平性变化存在差异;(2)武汉市中心城区公园绿地空间公平性评价结果并不理想,"严重不公平"级别所占面积比重始终比较大;(3)区域性公园绿地的空间公平性要优于全市性公园绿地的空间公平性;(4)公园绿地空间分布呈现不均衡特征,空间公平性的区域差异较大。街道人口数量、公园绿地数量、公园绿地的服务能力是造成其空间公平性区域差异的重要因素。因此,应该结合人口需求科学地规划公园绿地的数量和等级,以实现公共资源的有效利用。

Public green plays a significant role in improving living standards. As an important public resource, the service scope of public green must cover a larger area to satisfy the recreational needs of residents and make good use of its social service functions. The commonly used indices for measuring the function of public green ,such as average public green and overall percentage green area can hardly reflect the distribution of public green. Previous studies usually measured accessibility of public green spaces in order to allocate resources but have failed to reveal relationships between demand from population and supply generated by public green, and neglected the influence of range attenuation on supply and need. To discuss spatial equity of public green at resident parcel, this article chooses seven administrative districts in Wuhan as a case study area and uses the gravity two-step floating catchment area method with distance decay. The results show that：（1） the distance can change the pattern of spatial equity and there are existing notable differences in different level of public green when the catchment makes changes. （2） Majority of case area have an oversupply or undersupply service of public green, while some area has insufficient access to public green within the catchment sizes of 0.50h or 0.75h. （3） Within the same catchment size, the local level of public green can provide better services for residents than district public green. （4） The vast area characterized by unbalanced distribution of spatial equity, which have differences at different sub-districts. The primary factors, such as service capacity, amount of population or public green, have effect on the pattern of spatial equity. The article demonstrates that it is necessary to allocate public green considering the demand from residents to utilize public facility effectively.