黄河下游的岸滩侵蚀

Riverbank Erosion in the Lower Yellow River

黄河下游的滩岸侵蚀相当严重 ,尤其在游荡型河段。本文首先提出了滩岸侵蚀的概念及其侵蚀速率的定义 ,同时提出了利用现有水文观测资料研究滩岸侵蚀速率的方法。然后以三门峡水库建库前和蓄水拦沙期黄河下游河道的滩岸侵蚀情况为例 ,讨论了滩岸侵蚀机理及其主要影响因素。最后以实测资料为依据 ,经分析得出了不同河段滩岸稳定性系数及其侵蚀速率的变化范围 ,并建立了滩岸侵蚀速率的经验关系式。

Bank erosion, including lateral erosion and bank failure, is one of the most important fluvial processes in the Lower Yellow River, especially when the upstrearm reservoir impounds water and releases low sediment laden flows. In this paper, conceptions of bank erosion and its retreat rate are presented, and a new procedure to analyze the bank erosion rate is proposed. Then mechanisms of bank erosion and influencing factors are systematically discussed through using the bank erosion in the river channel downstream of the Sanmenxia Reservoir as an example. Finally, based on the analysis of field data, the ranges of erosion rate for different reaches in the Lower Yellow River are obtained. It is shown that the bank erosion rate is closely related to the stability coefficient and geomorphological coefficient.