城镇化进程中生态承载力系统耦合时空格局及影响因素——以洞庭湖区为例

Spatiotemporal Pattern and Influencing Factor of Coupling of Ecological Carrying Capacity in the Process of Urbanization:A Case Study of Dongting Lake Region

基于城镇化过程中生态承载力耦合关系的形成机理,构建生态承载力3个子系统评价指标体系,运用耦合协调模型、探索性空间数据分析法和因子探测器,分析2001—2019年洞庭湖区城镇化过程中生态承载力系统耦合时空格局特征及影响因素。结果表明:(1)在城镇化率稳定上升的过程中,耦合协调度呈现快速增长—缓慢下降—稳步上升的变化趋势,增幅为125.3%,达到0.6708,进入高度协调阶段;但协调性滞后于耦合性,湖区生态压力依然严峻。(2)17个县域耦合协调度的空间差异明显,低度协调和中度协调的县域所占比重大,生态承载力内在协调水平有待提升。地域分布上整体表现为“M”型的空间格局。(3)耦合协调度具有较强的正全局空间自相关,空间集聚特征显著,时空分布存在着冷点和热点区域,且出现了一定程度上的演化和迁移,但“M”型的空间格局依然明显。(4)热点区域的地域分布格局表现为洞庭湖核心区为冷点区,边缘区为热点区,外围区为次冷点区和次热点区,呈镶嵌分布。空间集聚演化格局基本稳定,但热点区出现了沿主要交通干线不断扩张的现象。(5)不同类型探测因子对耦合协调度的影响力存在时序差异,压力类因子最强,响应类次之,状态类最弱,这种差异性影响力是时空变化的关键因素。

This paper constructs the evaluation index of three subsystems of ecological carrying capacity on the basis of the formation mechanism of coupling relationship of ecological carrying capacity, and analyzes its spatiotemporal evolution characteristics and influencing factors in 2001-2019 by the means of the methods of coupling coordination model,exploratory spatial data analysis and geographical detector. The results shows that: 1) The urbanization rate raised steadily, the coupling coordination degree presented a trend of "rapid growth-slow decline-steady rise", the growth rate increased by 125.3%,entering a highly coordinated stage. Coordination lagged behind coupling,the ecological pressure in the Dongting Lake region was still severe. 2) The coupling coordination degree had obvious spatial differences in 17counties, counties with low and moderate levels account for a larger proportion, the internal coordination of ecological carrying capacity needed to be improved. It overall presented the "M"-shaped spatial pattern. 3) The coupling coordination degree had strong positive global spatial autocorrelation, the spatial agglomeration characteristics were remarkable. In terms of spatiotemporal distribution, there were cold-spot and hot-spot areas with a certain degree of evolution and migration,but the "M"-shaped spatial pattern was still obvious. 4) Cold-spot areas distributed in the core area of Dongting Lake,hot-spot areas distributed in the fringe area. The secondary cold-spot areas and the secondary hotspot areas distributed in the periphery,and inlaid around the core and marginal areas,the spatial agglomeration evolution pattern was basically stable. However, the hot-spot areas had been expanding along the main traffic arteries. 5) The influence of different detection factors on the coupling coordination degree varied in time series,the stress factor was the strongest, the response factor came next followed by the state factor, this differential influence was a key factor in spatiotemporal evolution.