平原河网区河流连通性评价研究

河流连通性对流域水文过程特征、水环境条件以及河湖蓄泄能力等有较大影响。平原河网地区是河流高度发育并受到城市化等人类活动深刻影响的区域，并且区域内水系结构破坏、河流连通受阻已成为洪涝灾害频发的重要原因之一。为此通过对现有的河流连通评价方法的分析，尝试建立基于水流阻力与水文过程的平原河网河流连通性评价方法，并以鄞东南平原河网为例开展了应用分析，结果表明2010年的河流连通性比1990年的明显减小。同时，通过对比分析几种河流连通性评价方法可以看出，基于水流阻力与水文过程的河流连通性评价方法能较好的评价平原河网区河流连通性，评价结果优于其他方法计算结果，更符合实际情况，可为平原河网区河流连通性定量评价提供参考

STUDY ON RIVERS CONNECTIVITY EVALUATION IN PLAIN RIVER NETWORK AREA

River connectivity has a great influence on characteristics of watershed hydrological processes, water environmental condition and the capacity of lakes drainage storage, etc. At present, the connectivity of a river lake system has become the new strategy to promote water safety management in our country. Drainage structure damage and increasing connectedness of rivers have become one of the most important causes of frequent floods and waterlogging in plain river network regions which are highly developed and deeply influenced by urbanization and human activities. Therefore through the analysis of the existing river connected evaluation method, we proposed a new river connectivity evaluation method of plain river network based on the flow resistance and hydrological processes. Based on the river system of three periods of 1990, 2003 and 2010, the proposed approach has been tested on a river network of the Yin southeast plain. The results indicated that the rivers connectivity decreased more significantly in 2010 than in 1990. At the same time, by analyzing and contrasting several rivers connecting evaluations methods, it can be seen that river connectivity evaluation method based on water flow resistance and the hydrological processes can evaluate rivers connectivity of the plain river network area better, and the calculation result is superior to that from other methods because it coincides better with the actual situation. The river network connectivity evaluation method based on water flow resistance and river hydrological processes can evaluate river connectivity and on the corresponding relationship to rainfall runoff synthetically. It can well explain the influence the river connected degree on flood drainage, and river connected degree is higher, the ability of river flood and waterlogging drainage is stronger. The study can provide the reference for rivers connectivity quantitative evaluation of the plain river network area