渭河下游河道淤积发展及其萎缩的原因浅析

在实测资料的基础上，引入河道萎缩的量化指标．通过建立渭河下游泥沙累积淤积量、河道萎缩量化指标与潼关高程和渭河来水来沙条件的关系发现，潼关高程的抬升是渭河下游淤积发展及河道萎缩的主要原因之一，渭河来水来沙条件变化也是一个不容忽视的重要影响因素。

Riverbed Aggradations and Main Channel Shrinkage in the Lower Reach of the Weihe River

The lower Weihe River is a part of Sanmenxia reservoir. Due to the lack of enough study on the characteristics of incoming water and sediment in building the reservoir, serious sediment silt in the reservoir not only made Tongguan riverbed rise rapidly, but also caused environment upstream watershed of Tongguan seriously deteriorated. The lower Weihe River has been impacted most, and a series of disasters has occurred in that area. However, the reasons resulting in riverbed aggradations and shrinkage were not understood well. In this paper, the quantitative index of channel shrinkage was introduced to analyze the relationships among the main channel shrinkage (such as riverbed slope and flood conveying capacity in the main channel), Tongguan riverbed elevation, incoming water and sediment condition, and the accumulative silt amount. Finally the following conclusions was drawn: Tongguan riverbed elevation is the main factor impacting on the riverbed aggradations and channel shrinkage in the lower reach of Weihe River, and the annual runoff decrease is not negligible factor either.