水沙调控对黄河下游河道的人工影响

Artificial Influences of Water and Sand Regulation on Lower Reach of the Yellow River

黄河下游发生漫滩洪水时,基于小浪底水库的调控作用,研究通过滩区控制性分滞洪,实现下游河道淤滩刷槽、减缓"二级悬河"发展的目标.选取夹河滩—高村为典型河段设计模型,依据"82·8"漫滩型洪水进行了不同水沙组合及不同分滞洪方案的物理模型试验.试验结果表明:研究河段主槽冲刷,滩地淤积,洪水后河道整体呈现淤积状态,部分泥沙被拦截在河漫滩内;河槽在涨洪及洪峰前后强烈冲刷,落峰期主槽有一定回淤;在中水河槽较宽、二滩面积较大的河段,滩地淤积量较大.

When the overbank flood occurs in the Lower Yellow River, based on the regulation of Xiaolangdi Reservoir, the flood diver- sion and detention controlled by the beach area can realize the goals of silting beach and scouring channel in lower reach of the Yellow River and slowing down the development of secondary suspended river. Selecting Jiahetan-Gaocun for a typical reach of the design mod- el, a series of physical model tests were conducted in the conditions of different combinations of water and sediment and different flood diversion and detention programs according to ＂ 82.8＂ overbank flood. Test results showed that： the main channel of the reach was scoured while the beach was silted; the whole river channel appeared deposition after the flood as well as some sediment was blocked within the floodplain; the channels were scoured strongly when flood rising and before and after flood peak, and the main channel ap- peared back-silting during the period of flood peak falling ; the deposition amount of the beach was larger in the reaches where the chan- nel was wider, and the area of second beach was larger.