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

When the overbank flood occurs in the Lower Yellow River,based on the regulation of Xiaolangdi Reservoir,the flood diversion 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 model,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 appeared back-silting during the period of flood peak falling; the deposition amount of the beach was larger in the reaches where the channel was wider,and the area of second beach was larger.