Study on the Construction of the Ecological Security Pattern of the Lancang River Basin (Yunnan Section) Based on InVEST-MSPA-Circuit Theory

Optimizing the pattern of land space development and protection as well as improving regional ecological security are significant tasks in the construction of an ecological civilization. The Lancang River Basin is a significant ecological barrier in Southwest China, and its ecological security is critical to the Natural World Heritage Site of “Three Parallel Rivers” and even to Southeast Asia. In this study, the InVEST model and MSPA method were used for the identification of the ecological sources; the resistance surface was corrected by the night light coefficient; and the ecological linkages, pinch points, obstacles, and ecological breakpoints were extracted using the circuit theory to construct the ecological security pattern of the Lancang River Basin. The major study results indicated that: (1) A total of 23 ecological sources were identified in the watershed, covering an area of 9019.56 km2, mostly large-scale irregular patches. (2) A total of 39 ecological corridors were identified in the study area; 15 key corridors, 17 important corridors, and 7 general corridors were extracted based on the gravity model, which together formed a ecological security network for the watershed. (3) Sixteen ecological pinch points, one primary ecological improvement area, twelve secondary improvement areas, and twenty-nine ecological breakpoints were identified in this study. The ecological protection and restoration of different important ecological areas are conducive to the protection of biodiversity and the construction of the ecological security pattern in the Lancang River Basin.