Multi-functional green infrastructure network optimization in rural qinba mountains: a source-sink approach to resolving spatial conflicts

The development of rural green infrastructure composite networks (GICN) represents a crucial strategy to reconcile ecological conservation with sustainable development in the Qinba Mountain Area. In response to the prevalent issue of functional singularity in current practices, a multi-functional coupling framework is proposed in this study, with Yang County taken as an example. This framework overcomes the spatial limitations of previous rural green infrastructure construction and builds a rural GICN integrating “ecology-recreation-climate”. The framework comprises three key methodological components: single-objective network construction, composite network coupling, and multifunctional trade-off optimization. Key research findings revealed: (1) Distinct spatial differentiation patterns, with ecological, recreational and climatic “source” landscapes predominantly distributed in mid-to-high altitude natural zones along the southern slopes of the Qinling Mountains in northern Yang County, while “sink” landscapes concentrate in the urban core and surrounding high-density built-up areas; (2) Characteristic corridor configurations in single-objective networks, exhibiting a central clustering-peripheral dispersion spatial pattern for both “source-source” and “source-sink” connections, with unidirectional connectivity identified in certain ecological source areas; (3) Successful establishment of a GICN system consisting of 15 composite source areas, 13 composite sink areas, and 66 composite corridors, forming an efficient annular structure; (4) Implementation of an optimized “One Axis-Two Loops-Two Belts” spatial layout, with the composite axis along the Youshui River effectively integrating multiple functions including ecological restoration, recreational connectivity and microclimate regulation. This study develops an integrated planning methodology for rural GICN that simultaneously addresses ecological security, recreational services, and climate adaptation, providing both scientific foundations and practical paradigms for sustainable development in mountainous counties.