Authors: ZHAO Jin-yong, DONG Zhe-ren, ZHAI Zheng-li, SUN Dong-ya (China Institute of Water Resources and Hydropower Research, Beijing 100038, China)

Abstract: Connectivity of river system is an important factor to maintain the health of river ecosystem. Based on the concept of connectivity in graph theory, micro-geomorphic units such as flow channel in river-floodplain system, topography of hogback, small closed water and oxbow lake are generalized with graph model and realized by ArcGIS platform and DEM model. On this basis, the adjacency matrix of the graph model has been built, and the analysis and calculation of connectivity were carried out to realize the quantitative analysis of connectivity property in river-floodplain system. Taking the river-floodplain system in Lishui Reach of the Oujiang River as a pilot research case, the connectivity at a certain water level was simulated and analyzed quantitatively. The result indicates that making certain key flow channel and confluent point of flow channels can optimize the scheme of river restoration project, the method proposed here is effective and feasible in evaluating the river-floodplain system connectivity. The evaluation method can be utilized in the fields of river health assessment, river restoration projects optimization and river-lake water net work connectivity analysis.

Key words: river-floodplain system, connectivity, river restoration, graph theory, adjacency matrix

Published in: Journal of Hydraulic Engineering, Vol. 42, No. 5, 2011
Article ID: 0559-9350 (2011) 05-0537-07