Spatial resilience assessment and optimization of small watershed based on complex network theory

Abstract

The loess hilly and gully region is an ecologically fragile area with poor ecological restoration and service capacity. Enhancing regional spatial resilience is conducive to upgrading carrying capacity and service capability of local ecosystems. Focusing on the Sanshuihe River Basin, this study intends to explore watershed ecosystem based on complex network theory and constructs a research framework of “space simulation - resilience assessment - spatial optimization”. The results show that the Basin forms a network structure based on lakes, wetlands, scenic spots and parks, with 36 ecological nodes and 60 ecological corridors in total. In the future, there will be 16 additional ecological nodes and 38 ecological corridors in the Basin, thus further stabilizing its ecosystem and enhancing connectivity and recreational attributes. Besides, the independence, collaboration, connectivity, interdependence, stability and functionality of ecological nodes grow by 14.9%, 10.4%, 10.0%, 51.4%, 5.77% and 33.20%, respectively. In the end, the study defines the boundary for water conservation, recreational area and forest conservation area in the watershed, divides functional ecological corridors into four types, classifies the importance of the development (protection) of ecological sources, and comes up with corresponding schemes for spatial optimization. The research findings can not only offer guidance for the assessment and optimization of spatial resilience of small watershed, but also lay a basis for regional ecological restoration, resource exploitation and ecological network planning.