Assessment of ecological resilience in Nanchang based on "risk-connectivity-potential".

With the rapid development of urban construction, land for construction continues to expand and the ecological land is shrinking. There are various risks and degradation phenomena. The evaluation of urban ecological resilience thus becomes particularly important. From the perspective of urbanization-induced landscape changes, we evaluated the ecological resilience level of Nanchang from 2005 to 2020 by means of "risk-connectivity-potential" model, spatial autocorrelation model and kernel density assessment, as well as its spatial-temporal variations. The results showed that from 2005 to 2020, the spatial pattern of risk, connectivity, and potential subsystems in the study area was stable, with significant differences. The ecological risk was high in the middle and low in the east and west, while the spatial distribution of connectivity and ecological potential was opposite to the ecological risk, showing a pattern of low in the middle and high in the east and west. The overall level of ecological resilience was not high, with medium and low resilience levels as the main body. The low level continued to grow, and high value areas gradually decreased. The "high-high" cluster type of ecological resilience was decreasing, while the "low-low" cluster type was gradually increasing. Results of Kernel density assessment showed that the overall resilience level of Nanchang had little change, with obvious spatial difference. The number and distribution of different landscape types should be adjusted according to the characteristics of the ecological resilience level of different regions, in combination with the urban planning layout. The connectivity and agglomeration of spatial distribution of different landscape types should be changed to achieve the optimization and improvement of the overall regional ecological resilience level. The results could provide a theoretical basis for urban spatial planning and layout.随着城市建设的快速发展,建设用地持续扩张,生态用地不断缩减,城市生态系统出现了各种风险和退化现象,故对城市生态韧性进行评估尤为重要。本研究从城市化进程带来的景观地类变化视角出发,通过“风险-连通性-潜力”模型、空间自相关模型及核密度评估等方法对南昌市2005—2020年生态韧性水平进行评估,并探究其时空演化特征。结果表明: 2005—2020年,研究区风险、连通性和潜力各子系统空间格局稳定,但差异显著,其中,生态风险呈中部高、东西两侧低的特征,连通性和生态潜力的空间分布则与生态风险相反,呈中部低、东西两端高的格局。南昌市生态韧性整体水平不高,以中、较低韧性水平为主体,低等级持续增长,高值水平区域逐渐减少。生态韧性的“高-高”集聚类型不断减小,“低-低”集聚类型逐步增加。核密度评估表明,南昌市整体韧性水平变化不大,空间差异明显。应根据南昌市不同区域的生态韧性水平特征,结合城市规划布局调整不同景观类型的数量与分布,改变不同景观类型空间分布的连通性和集聚性,实现区域整体生态韧性水平的优化提升。研究结果可为城市空间规划布局提供理论依据。.