黄河调水调沙

黄河下游河道淤积的主要原因在于“水少沙多，水沙不平衡”，按照黄河下游河道冲淤规律，只要把进入黄河下游河道的不平衡的水沙关系调节为协调的强大功能。小浪底水库位于控制进入黄河下游河道水沙的关键部位，该水库控制了黄河径流量的91％，控制了近100％的黄河泥沙，2002年7月4日进行的黄河首次调水调沙试验控制花园口断面流量不大于2600m^3/s，平均含沙量不大于20kg/m^3，小浪底水库泄流历时不少于10天，黄河下游河道共冲刷泥沙0．362亿t，试验达到了预期的目的。通过这次试验，共取得测验数据520万组，这为今后建立更加符合原型黄河实际的数学模型和实体模型提供了极其重要的物理参数，试验证明，利用水库调水调沙，将不协调的水沙关系调节为相协调的水沙关系，是有利于输沙入海、减轻下游河道淤积甚至冲刷下游河道的有效途径之一。

The Yellow River Water and Sediment Regulation

The main reason of aggradation happened in the lower Yellow River is because of less runoff, too much sediment and unbalanced amount of water and sediment. According to the law of scouring and deposition of the channel, it can totally avoid that situation in the lower reaches if only to regulate the unbalanced relationship of water and sediment in the lower reaches into a balanced relationship. The Xiaolangdi Reservoir built on the Yellow River and completed by the end of 2001 has powerful functions to regulate the unbalanced relationship of water and sediment. The Xiaolangdi Reservoir is situated on the key position where can control the water and sediment entering into the lower reaches. It has controlled 91% of the river runoff and almost 100% of the river sediment. The discharge controlled at Huayuankou cross section during the first water and sediment regulation test conducted in the Yellow River is 2 600 m 3/s, the mean outlet sediment concentration less than 20 kg/m 3 and duration is 11 days. In the test, it has totally flushed out 36.2 million tons of sediment and achieved the desired purpose. Through the test, we have collected 5.2 million sets of data and have a better understanding on the laws of riverbed evolution, water and sediment. It has provided extremely important physical parameters for establishing a mathematical model and a physical model that will further tally with the actual real river in the future. It is shown by the test that it is one of the effective way to be beneficial for delivering sediment into the sea, reduce aggradation of the lower river channel and even scour the lower river channel to regulate the unbalanced relationship of water and sediment into a balanced relationship by using a reservoir for water and sediment regulation.