黄河沙漠宽谷段河床演变特征及影响因素

Evolution Characters and Influencing Factors for Riverbed of the Desert Wide Valley Section of the Yellow River

根据黄河沙漠宽谷段巴彦高勒—三湖河口河段代表年份水沙条件、河道大断面定位观测资料,结合前人研究成果,分析了黄河沙漠宽谷段代表年份汛期和非汛期水沙关系的变化特点、河床演变特征及大型水库的调控作用。结果表明:刘家峡水库运用后来水来沙量减少,特别是刘家峡、龙羊峡水库联合运用后来水来沙量进一步削减,且减少量主要发生在汛期;水沙关系的变化引起河床抬高、平滩流量减小,河道摆动严重;引起水沙关系变化的主要因素是天然降水量减少、引水量增加、上游水库调控运用及风沙入黄。

According to the water and sediment conditions, river observations of large sections about representing years of Bayan Gol--Sanhehukou which is a wide valley of the Yellow River, it analyzed the characters of water and sediment relation, riverbed evolutions and reservoir regulations of the wide valley of the Yellow River. The results show that ： the water and sediment reduce after the use of Liujiaxia Reservoir, especially the joint operation of Liujiaxia and Longyangxia reservoirs. And the reduction mainly happens in flood reasons. The changes between water and sediment cause the waterbed elevation, bankfull flow decreases and the channel shifts seriously. The main reasons of water and sediment changes are de- creased natural precipitation, the amount of water diversion increase, the regulation operation of reservoirs on the upstream and sandstorms entering into the Yellow River.