Impact of artificial modifications on the structure and robustness of the Haihe River network

Abstract

Study region

Haihe River Basin, China.

Study focus

This study employed complex network theory to investigate the impact of artificial modifications on the Haihe River Network. We constructed topological models of the natural and current river networks, assessed key functions (flood protection, water supply, and ecological), and analyzed changes in network hierarchy, clustering, and transmission. Network robustness was assessed through node and edge removal simulations under static and dynamic attack scenarios, including function-weighted and centrality-based strategies. This analytical method, integrating network indicators and functional weights, innovatively reveals differences in robustness between natural and current river networks and offers a new perspective for river network optimization.

New hydrological insights for the region

Artificial modifications have enhanced the Haihe River Basin's connectivity (average degree increased by 20 %), strengthened network clustering (largest component size rose from 0.218 to 0.981), and improved transmission (global efficiency increased fivefold). Static attack simulations highlighted the critical role of the Yongding River, particularly its tributary, the Sanggan River, whose removal resulted in a 42.25 % decrease in the largest component size in the natural network. Dynamic attack simulations identified vulnerability thresholds, emphasizing the importance of high-betweenness nodes and water supply-weighted edges. These thresholds are especially evident in the network's sensitivity to disruptions of the Middle Route of the South-to-North Water Diversion Project and the Beijing-Hangzhou Grand Canal.