Network structure and stability of the river connectivity in a rapidly urbanizing region

Abstract

River connectivity, which is key to the function of the river network, is deteriorating in highly urbanized areas. While previous studies have identified changes in the structure and connectivity of river networks, few studies have described the network structure of river connectivity and revealed the effects of urbanization on network structure. To this end, we detected the network structure and stability of river connectivity from a novel perspective of complex network theory. Taking the Taihu Plain as an example, we found that 1) the node degree of the river network was moderate (2.9), and the hub and connectivity were low (0.21 and 0.19, respectively). The hub and connectivity of the river network in the Yang-Cheng-Dian-Mao (YCDM) region were better than that in Wu-Cheng-Xi-Yu (WCXY) and Hang-Jia-Hu (HJH) regions. 2) The destruction of important nodes led to a dramatic decrease in the stability of river network connectivity. The river network structures on the Taihu Plain, HJH, WCXY, and YCDM were severely damaged when the removal rate of river network nodes exceeded 5 %, 7 %, 16 %, and 22 %, respectively. 3) The spatial response of the river network to urbanization was mainly negative, especially in highly urbanized regions. The effects of urbanization on network characteristics could be sorted as node degree (45 %), hub (21 %), and connectivity (18 %). Our results would provide theoretical support for the recognition, protection, and restoration of the river network in rapidly urbanizing regions.

Keywords: Complex network theory; Network structure; River connectivity; Taihu Plain; Urbanization.