城市生态空间冲突分析与系统优化方法

Conflict analysis and system optimization of urban ecological space

为适应国土空间整合理论方法的迫切需求,建立由冲突源、冲突区、冲突影响组成的城市生态空间冲突分析框架,其案例应用表明:城市生态空间的社会经济第一冲突源并不突出,政策驱动力构成首要冲突源;城市汇水区渗透性能下降,产流增加,汇流速度加快,形成上游高地型、中下游沿岸型、下游低洼型及沿山型等4种冲突类型,采用城市雨洪模型(SWMM)辨识出4种内涝区及分布类型;针对冲突源、空间优化核心和末端排水建立城市生态空间系统优化目标体系,重点提出"点线面"结合的空间优化核心路径。研究为国土空间整合提供理论与方法支撑,并涵盖国际雨洪管理演替过程,有助于对当前大规模土地开发转型及海绵城市建设理念的本土认识。

On the basis of the needs of national land space integration theory and method, the paper explores the system optimization method of urban ecological space adapting to the local development characteristics of China’s rapidly urbanized areas.(1) Firstly, from the perspective of landscape or land composition based on CHANS(coupled human and nature system), the elements of urban ecological space system are deconstructed as ecological space and urban space. Then, the process framework of urban ecological space conflict analysis is established,which includes three aspects: conflict source, conflict area and conflict impact. The conflict source refers to the driving force of urban spatial growth and the source of ecological spatial change. The pressure of urban spatial change on ecological space results in the formation of ecological spatial conflict area under the conflict source. The consequences of various urban ecological functions(processes) are caused by conflict factors and conflict areas. Lastly, the way of system optimization is proposed based on the systematic diagnosis of conflict process and causes.(2) The case study of rapid urbanization shows that the first conflict source of social and economic activities in urban ecological space conflict is not prominent, and the policy driving force constitutes the main conflict source and runs through the whole conflict process. Through the analysis of road network and land layout planning process, the type and conflict mechanism of conflict area between urban and natural catchment areas are revealed,and the SWMM model is used to simulate and identify four flooding types and key causes.(3)Therefore, the system optimization objectives of urban ecological space are constructed respectively for conflict sources, conflict areas and conflict impact. The traditional optimization objectives aim at the drainage process and facilities formed by end-conflict impacts, and the core objectives aim at the key causes of formation of flooding areas, i.e. the enhancement of storage function and reconstruction of spatial elements in conflict areas of urban ecological space change. The fundamental optimization objectives aim is to change system, policy and planning of urban ecological space. The spatial optimization framework consisting of three types of main functional optimization areas, six types of key points and five types of key channels is identified for the case area. The framework of conflict analysis and the method of system optimization in the paper provide reference for the study of national land spatial integration. The case study covers the succession process of international stormwater management as a whole, which is helpful for the local understanding of the current large-scale land development transformation and the concept of sponge city construction.