Complex network-based analysis of inter-basin water transfer networks

Driven by water resources scarcity, inter-basin water transfer (IBWT) projects have emerged and evolved, thereby shaping the current water supply framework. As IBWT projects increase, they gradually acquire network characteristics, giving rise to IBWT networks. However, the impact of the development of IBWT networks on water-supply patterns remains unclear? Analyzing the spatial and temporal growth patterns of IBWT networks through the lens of complex network theory can help answer this question. This study established a framework for analyzing IBWT networks using complex network analysis (CNA). Within this framework, we analyzed the spatial and temporal development characteristics of the IBWT network by quantifying its global properties across three dimensions: efficiency, elasticity, and coordination. Six centrality indicators were employed to measure the significance of individual nodes. Finally, the Infomap method was employed for network community detection. The results demonstrated that the CNA-based framework effectively captured the comprehensive development of the IBWT network, which underwent six stages from inception to high-speed, near-term, and long-term Stages. IBWT network efficiency, elasticity, and coordination all showed growth, which was most pronounced in 2013–2022, where the scaled global efficiency, network efficiency, average node connectivity, and average betweenness centrality metrics all grew by a factor of greater than 4. Importantly, the total percentage of centrality greater than 0.2 in the Huang-Huai-Hai-Chang Basin was 63.0%. The 125 initial IBWT projects in the IBWT network contained 58 communities, while the subsequent construction of 57 projects added only 12 communities. Future new IBWT network projects will tend to joined existing communities.