论三峡水库下游的河床冲淤变化

A Study on Riverbed Erosion Downstream from the Three Gorges Reservoir

回顾和分析了三峡建库前后坝下游汉口以上河段的冲淤情况.通过分析丹江口、三门峡等水库下游实测资料表明,在水库下游河床冲刷、沙量恢复过程中,各粒径组输沙量均不会超出建库前水平,这是与河床边界、河型等因素无关的一般性规律.目前三峡水库下游冲淤计算成果与其他水库下游的冲淤规律存在矛盾之处,汉口以上河段冲淤情况以及对防洪的影响值得商榷.

In this article, riverbed erosion process downstream from the Three Gorges Reservoir before and after the reservoir operation is reviewed and analyzed. Field data from the Danjiangkou and Sanmenxia Reservoirs indicate that through the riverbed erosion and sediment concentration recovery process, sediment transportation capacity of each grain group size after the reservoir operation can′t exceed its original level before the reservoir′s operation. This is a common law and has little relation with river types. Results of current related researches about the middle reaches of the Yangtze River conflicts with the common erosion behavior of river reaches downstream from reservoirs. This suggests that the present predicted process of sediment concentration recovery and riverbed erosion is improbable.