一、建設拦沙库的理由建設黄河拦沙庫的目的,是为拦住黄河干流带来的大量有害的泥沙,以減輕三門峽庫区和京广铁路以东下游河槽的淤积。拦沙庫的寿命可詨計为五、六十年,使在淤滿以前,下游广大地区得到安全保障,并为在黄河中游进行水土保持工作赢得足够的时間。黄河流經山陝峽谷吋,从两岸的溪澗里接受了大量的泥沙,在潼关又接受了由涇、洛、渭河輸送来的 I. Reasons for building a sand-blocking dam The purpose of building a sand-blocking dam of the Yellow River is to stop a large amount of harmful sediment brought by the mainstream of the Yellow River in order to alleviate siltation in the lower reaches of the Sanmenxia Reservoir area and the east of the Jing-Guang Railroad. The life expectancy of the sand-blocking depot can be counted as five or six decades, so that before the silting up, the security of vast areas downstream has been won and enough time has been gained for soil and water conservation work in the middle reaches of the Yellow River. When the Yellow River flows through the Shanshan Canyon, it has received a great deal of sediment from the streams on both banks of the Yellow River. In Tongguan, it has also received the transportation from Jinghe, Luohe and Weihe River