Spatiotemporal changes and driving forces of ecological security in the Chengdu-Chongqing urban agglomeration, China: Quantification using health-services-risk framework

Exploring the patterns of ecological security and its driving mechanisms is crucial for ecosystem management and regional development. However, few studies have conducted the ecological security evaluation from multiple perspectives of ecosystems, and the relative importance and spatial heterogeneity impacts of human activities, natural and landscape structural on ecological security changes need to be further explored. In this study, a health-services-risk framework was developed to evaluate ecological security pattern of the Chengdu-Chongqing urban agglomeration (CCUA) from 2000 to 2015. Then, the geo-detector method and geographically weighted regression model were employed to investigate the relative importance and spatial heterogeneity of various factors on ecological security changes. The results showed that (1) the comprehensive ecological security index (CESI) pattern in the CCUA increased from the central plains to the surrounding mountains. About 14.61% of the regional ecological security had declined from 2000 to 2015, which was concentrated in the plains and around the core cities, while the southwest and northeast experienced a evident increase in CESI. (2) Human activity were the dominant factors in CESI changes, followed by natural factors and landscape structural factors. The great influence of natural and landscape structural concentrated in the southwestern and northeastern mountainous areas, while the significant influence of human activities occurred in the plains areas in the central and western parts. The proposed framework can be applied to the security evaluation of other rapidly urbanizing areas, and the findings will help the ecological conservation and sustainable management of the CCUA.