80年代黄河下游河道冲淤演变分析

Analysis on Scour and Silting of the Channel in the Lower Yellow River in the Eighties

综合各种实测资料,80年代黄河下游年平均淤积量小于1亿t,是1919年以来(除三门峡水库拦沙期)淤积量最少的一个时期。其中1981～1985年由于来水来沙条件十分有利,黄河下游连续五年均发生冲刷,五年累计冲刷量为4.81亿t;1986～1989年黄河进入连续枯水段,下游河道发生淤积,在年来沙量不足8亿t的情况下,年平均淤积量达2.02亿t,且主要淤积在主槽内。由于河道主槽淤积速度高于滩地,致使80年代黄河下游大部分河段的排洪能力都有所下降。文章最后还对河口段河道冲淤变化及其延伸影响进行了分析。

Besed on the analyzing various recorded information, the paper points out that annual average sediment amount silted in the lower Yellow River in 1980s was less than 100 million tons, which has been the least value since 1919 (except the silting period of Sanmenxia Reservior). Due to the available condition of runoff and sediment from 1981 to 1985, the riverbed of the lower Yellow River kept scouring still and the total scour amount added up to about 481 million tons during this period. But it was silted, mainly in the main channel. During the successive lower water period from 1986 to 1989, and the annual average amount of siltation reached to 202 million tons under the condition of less than 800 million tons of sediment load per year. Because the silting rate on main channel was higher than on the flood plain, the carrying flood capacity of large part of the reaches of the lower Yellow River in 1980s reduced. At least, the variation of scour and silting in the section of river mouth and its strenchment are also analysed.