干旱区生态环境知识资源中心

Bank collapse refers to the avalanche of bank material due to the basal erosion by hydrodynamic action, and results in substantial losses of farmland and nearby settlements, destruction of base facilities and deposition of river channel. Correspondingly, it has been paid great attentions that bank collapse brings about river channel processes and exerts adverse influence on land use and floods control engineering. There is lots of severe bank collapse in the upper Yellow River during flood, of which the typical representative is bank collapse at Dengkou reach (DK reach). By Landsat TM data from 2006 to 2010 and topographic maps of 1958 derived from aerial photos, river channel processes of erosion and accretion due to bank collapse at DK reach from 2006 to 2010 were analyzed preliminarily. The area of the processes was determined by comparing sequential changes at the position of the river boundary for these years based on Arcgis method. The results showed that the total area of river boundary retreat and advance from 2006 to 2010 equaled 742.25 ha and 708.71 ha respectively, and the river regime changed significantly with remarkable swing of mainstream and cross of both sides, because of serious bank collapse by specific bank composition properties, and flow discharge change at DK reach, and the sediment transport of bank collapse materials exhibits the law of that sediment transport from concave reach to convex reach is much more than that from convex reach to convex reach. Thus, this study has a vital referential significance for the management of the whole Yellow river and contributes to the development of desert river dynamics.