黄河下游河槽萎缩与防洪

河道的形态是在一定边界条件下来水来沙过程长期塑造的结果，通过定性分析探讨了河道滩槽结构形成的机理，证明了天然河流中滩槽稳定结构是洪水与枯水长期作用的动态平衡结果，来水来沙条件的趋势性改变将导致滩槽结构的改变，在一定条件下甚至出现无明显主槽的局面，一些季节性河流的例子进一步证实了这种推论，从黄河下游这些年河床变化的特征分析，如不能有效改变长期断流和主槽泥沙淤积状况，大堤约束较小的河南河段也有向无明显主槽的完全游荡性河流变化的趋势，顺堤行洪，大堤偎水的频率将大大增加，从防洪减灾角度出发，提出了黄河下游今后河道治理可能主要在于来水来源的合理调度，河道河势控制工程的管理和滩区防洪减灾软环境的建设等几个方面。

River Course Shrinkage and Flood Control of the Lower Yellow River

An obvious change of incoming water flow and sediment of the Lower Yellow River has contributed to the river course shrinkage.Data analysis shows that the discharge capacity reduction mainly occurred in the main channel.Some concept analysis illustrated that the flood problem may be more serious than previous situation but the flood may have a different form.For the new situation in the Lower Yellow River,the main problems for the flood prevention are on the adjustment of incoming water flow and sediment,regulation of river course controlling projects,and floodplain management.