Construction and optimization of ecological network in inland river basin based on circuit theory, complex network and ecological sensitivity: A case study of Gansu section of Heihe River Basin

The construction and optimization of ecological network is an effective way to ensure regional ecological security and achieve sustainable development. The present study is based on ecosystem services and circuit theory to construct an ecological network within the Gansu section of the Heihe River Basin. Through robustness analysis, the stability of this network is assessed, while combining it with ecological sensitivity to identify problem areas and potential threat areas. Furthermore, reasonable optimization strategies are proposed. The results indicate:(1) The basin identified a total of 61 ecological source, spanning an extensive area of 19,586 km2, which accounted for approximately 35.6% of the overall territory. Notably, the spatial distribution exhibited a higher concentration in the southern regions and a relatively lower presence in the northern parts. Furthermore, an impressive count of 132 ecological corridors was identified alongside 103 ecological pinch points and 31 barriers; all predominantly clustered within the southwestern region. (2) The robustness analysis results in the selection of 10 corridors based on the betweenness increasing edge, and the early stability is significantly improved after optimizing network robustness. (3) The ecological sensitivity was categorized into five levels, which were integrated with the ecological network and newly added corridors to optimize the areas of high sensitivity. The results provide a scientific basis for regulating water resources allocation in inland river basins and optimizing territorial space.