基于网络分析的城市生态空间结构优化——以常州市为例

经济社会的高速发展带来城市的快速扩张,造成城市生态空间的萎缩和生态功能的下降,城市生态安全受到严重威胁。系统研究城市生态空间结构,提出针对性保护和优化措施,对于城市的可持续发展具有重大意义。本研究以常州市为研究区,考虑城市生态空间的自然生态功能和社会服务功能两方面,构建基于自然生态的“源地-廊道”与基于人文生态的“供给-需求”两类生态网络,对于源地廊道生态网络,主要从节点重要性、网络连通性与稳定性进行定量分析,对于供给需求生态网络,主要从节点重要性、供需均衡与稳定性进行定量分析。结果表明: 常州市主城区源地廊道生态网络的连通性与稳定性水平不高,供给需求生态网络的稳定性水平一般且存在服务供给与需求的空间错位。从连通性与稳定性提升角度,提出新增12个源地节点与57条廊道的源地廊道生态网络优化方案;从供需均衡与稳定性提升角度,提出新增22个供给节点的供给需求生态网络优化方案。对比初始源地廊道生态网络,优化网络连通性水平提升10%,稳定性提升0.05;对比初始供给需求生态网络,优化网络的服务水平提升4%,网络稳定性提升0.10。最后,综合两类生态网络,分别针对现状保护斑块与新增节点两类对象,提出了保护与管理实施方案。

Optimization of urban ecological spatial structure based on network analysis: A case study of Changzhou City,China

The rapid development of economy and society leads to the rapid expansion of cities, resulting in the atrophy of urban ecological space and the decline of ecological function, as well as a serious threat to urban ecological security. It is of great significance for the sustainable development of a city to systematically analyze the structure of urban ecological space and put forward targeted protection and optimization measures. Taking Changzhou City as the research area and considering the natural ecological function and social service function of urban ecological space, we constructed two ecological networks, the “source-corridor” ecological network based on natural ecology and the “supply-demand” ecological network based on human ecology. For the “source-corridor” ecological network, quantitative analysis was mainly carried out from the importance of nodes, network connectivity and stability. For the “supply-demand” ecological network, quantitative analysis was mainly carried out from the importance of nodes, supply-demand equilibrium and stability. The results showed that the levels of connectivity and stability of the “source-corridor” ecological network in the main urban area of Changzhou were not high, the stability level of the “supply-demand” ecological network was general, and there was spatial mismatch between service supply and demands. From the perspective of connectivity and stability improvement, an optimization scheme of “source-corridor” ecological network with 12 additional source nodes and 57 corridors was proposed. From the perspective of supply-demand balance and stability improvement, an optimization scheme of “supply-demand” ecological network with 22 new supply nodes was proposed. Compared with the original “source-corridor” ecological network, the connectivity level of the optimized network was improved by 10%, and the network stability was improved by 0.05. Compared with the initial “supply-demand” ecological network, the service level of the optimized network was improved by 4%, and the network stability was improved by 0.10. Finally, we integrated the two ecological networks, and formulated the implementation plan of protection and management for both the current protected patches and the new ecological nodes.