Circuit theory-based ecological security pattern could promote ecological protection in the Heihe River Basin of China.

Building ecological security patterns is essential to maintain regional ecological security and achieve sustainable development in the inland river basins with ecologically vulnerable environment. Numerous methods have been developed to build the ecological security pattern. However, to our knowledge, rare studies have quantified to what extent the derived pattern can improve ecological protection in the future. Taking Heihe River Basin (HRB), the second largest inland river basin in China, as the study area, we applied the circuit theory to build the ecological security pattern of HRB, and simulated how our built pattern contributed to ecological protection using the CLUMondo model. The results showed that the ecological security pattern of HRB contained 17 ecological sources, 35 key ecological corridors, and some ecological strategic points. The ecological sources were distributed in areas with better ecological conditions such as the Qilian Mountain Nature Reserve and Heihe National Wetland Park. The ecological corridors showed a pattern of "two horizontal and three vertical belts." Pinch points were mostly close to ecological sources or distributed on the corridors that played a key role in landscape connectivity, while barriers were mainly distributed on the corridors with large ecological resistance in the middle and lower reaches. The optimal ecological security pattern presented a "one screen, one belt, four districts and multiple centers" shape in HRB and could more effectively promote ecological protection compared to current development and protection scenarios. Our study provides a reliable decision-making guide for ecological protection and restoration of HRB, and can be extended to build ecological security patterns for broad-scale arid areas.