Evaluation of Plain River Network Hydrologic Connectivity Based on Improved Graph Theory

Abstract

Based on graph theory, the river network was generalized by a graph model. Considering the influence of water quantity on the hydrologic connectivity of river network, the connectivity factor reflecting water quantity index was taken as the weighted value, the quantitative evaluation model of hydrologic connectivity degree was setted up. By calculating the river network weighted connectivity degree with MATLAB, the quantitative evaluation of river network hydrologic connectivity was realized. Taking the Qinhuai River Basin as an example, the HEC-HMS hydrological model was established for the simulation of short-term and long-term flood. The connectivity level of the river network in the basin under different scale floods was graded by the quantitative evaluation results of connectivity degree. The results showed that the constructed evaluation model has good applicability and reliability.