基于改进图论法的平原河网水系连通性评价

基于改进的图论法,概化河网水系为图模型,考虑水量对河网水系连通性的影响,以反映流域水量指标的连通因子为权值,构建水系连通度定量评价模型,应用MATLAB计算河网加权连通度,实现对河网水系连通性的定量评价。以秦淮河流域为例,构建HEC-HMS水文模型,模拟流域短期和长期洪水过程,分析不同规模洪水过程下流域河网水系的连通程度,基于连通度定量评价结果对连通性进行等级划分。结果表明洪量与连通度基本符合线性关系;短期洪水过程与长期洪水过程相比的连通等级较差;构建的评价模型具有良好的适用性和可靠性。

Evaluation of plain river network hydrologic connectivity based on improved graph theory

Based on improved 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 the water quantity index was taken as the weight and the quantitative evaluation model of hydrologic connectivity degree was built. MATLAB was used to calculate the river network weighted connectivity degree, and the quantitative evaluation of river network hydrologic connectivity was conducted. Taking the Qinhuai River Basin as an example, the HEC-HMS hydrological model was established and the short-term and long-term floods were simulated. The connectivity degree of the river network in the basin under different scale floods was analyzed. The connectivity was graded according to the evaluation results. The results show that the flood volume and the connectivity degree are basically linear. The short-term flood has a poor connectivity degree compared to the long-term flood. The evaluation model has good applicability and reliability.