城市扩张与生态空间非线性动态耦合关系梯度分析模型

Modelling Gradient Changes of Non-linear Dynamic Coupling Relationships between Urban Expansion and Ecological Land

探索城市发展与生态保护的交互耦合关系是科学实施新型城镇化战略的重要支撑。现有研究多关注宏观城市系统要素、结构、功能与生态环境之间的耦合关系,较少从微观尺度尤其是城市圈层结构视角揭示二者之间的非线性动态耦合关系及其空间梯度性。基于此,本文提出了城市扩张-生态空间复合系统的多维度量化指标体系,构建了城市扩张与生态空间演化之间动态耦合协调度的评估模型,分析了1985—2020年武汉市域、绕城高速环线和中心城区等不同空间梯度内城市扩张与生态空间的动态耦合关系变化规律。研究表明,城市扩张与生态空间的动态耦合协调度在武汉市行政区划范围与绕城高速环线-武汉市界范围内整体呈“S”型变化,2010年之前处于缓慢发展状态,之后快速升至高度协调状态;绕城高速环线范围内耦合协调度总体呈现“波浪式”上升,2005年之后在高速极限发展与螺旋式上升阶段波动变化;绕城高速环线范围内以及城市主城区的耦合协调度均接近“S”型,其中绕城高速环线至主城区之间的耦合协调度在2010年之前持续升至螺旋式上升阶段,之后则缓慢下降至高速极限发展阶段,而主城区的耦合协调度在2000—2005年已处于高速极限发展状态,之后则呈现围绕高值上下波动的状态。不同空间梯度内城市扩张与生态空间之间的耦合协调关系存在显著差异性,未来城市空间管控与绿色基础设施规划应因地制宜制定对应措施。

Exploring the coupling between urban development and ecological protection plays a key role in promoting the new urbanization strategy.The existing studies have largely focused on the coupling of urban system elements,structures,and functions,and the ecological environment at the macro scale,while their nonlinear dynamic relationships have been rarely explored across the spatial gradient.Here,we established a multi-criteria indicator system to quantify the urban-ecological composite system and proposed an integrated analytical framework to assess the dynamic coupling of this composite system.Taking Wuhan city as an example,we investigated the dynamic coupling between the urban expansion processes and the ecological space changes at different spatial domains(i.e.,the area within the third-ring road,the area around the high-speed ring road,and the urban center)during the period of 1985-2020.The results show that the area of construction land experienced a continuous growth from 1985 to 2020 with an increasing rate from the urban center to rural areas,while the area of ecological land decreased rapidly.The urban center had a more significant decline in ecological land than other areas.With the rapid urban expansion,the coupling of the urban expansion process and ecological degradation presented a S-shaped change in the urban center area and the area around the high-speed ring road in Wuhan city,which was less obvious before 2010 and afterwards became significant.In the area of the high-speed ring road,the coupling level showed an overall increase with fluctuations,e.g.,it fluctuated between the phase of highspeed development and the phase of spiral rise after 2005.For the area between the high-speed ring road and the urban center,the coupling level exhibited an approximate S shape,with a transition from a slow coordination state to the spiral-up state before 2010 and then a decline to the high-speed development state.In the urban center area,the coupling level was already at the stage of the high-speed development during the period of 2000-2005,and then fluctuated around high values.There were significant differences in the changes of coupling of urban-ecological system across spatial gradients of a city,which indicated that future urban space management and green infrastructure planning should be adapted to local conditions.