Comprehensive optimization of ecological network in inland river basin from the perspective of future development: A case study of Shiyang River, China

Ecological network (EN) identification and optimization is an essential research tool for safeguarding regional ecological security patterns and planning territorial space. Especially for the ecologically fragile inland river basins, EN optimization is of significance in ensuring regional ecological security and virtuous cycle of ecosystems. In addition, EN is a dynamically changing structural system that is more applicable to the regional development by optimizing it from comprehensive future development perspective. EN of Shiyang River basin was constructed on account of the circuit theory, and land use/cover changes (LUCC) of the basin in 2035 was predicted by PLUS model, so as to explore the ecological conservation priorities and formulate optimization strategies. 54 ecological sources (ESs) were identified, covering an area of 12,198 km², mainly in the southern basin. 133 ecological corridors (ECs) with an area of 3,176.92 km² were extracted. 38 ecological pinchpoints (EPs) and 22 ecological barriers (EBs) were identified respectively, which were mainly distributed in the lower basin. To effectively enhance the connectivity of EN in Minqin County, which has the worst ecological environment, we added five stepping stones based on the Ant Forest project. In addition, the optimal EPS is selected according to the development and limitation needs of inland river basins and the threat degree of warning points (WPs) under different scenarios. Scientific and reasonable optimization of future urban layout to prevent WPs can effectively alleviate the contradiction between ecological protection and economic development. The study is intended to provide basis for ecological sustainable development and rational planning territorial space in Shiyang River basin, as well as opinion for EN optimization in inland river basin.