三峡常年库区万州关刀碛河段河床演变

Riverbed evolution of the Wanzhou Guandaoqi reach in the area of the Three Gorges regular reservoir

万州关刀碛河段宽窄相间,为三峡常年库区典型代表河段。依据大量实测资料,分析三峡水库蓄水后该河段河床演变情况。研究发现:三峡常年库区河段并不是全河段淤积,呈现"点"或"段"分散淤积分布特征;泥沙淤积分布和淤积强度与河道形态存在着密切的关系,淤积平面分布主要在宽阔河段、弯道凸岸下首、深槽等部位;河道宽谷段淤积强度相对较大,窄深段淤积强度较小,甚至存在冲刷。

The reach of Wanzhou Guandaoqi is wide alternating with narrow, which is the typical representative reach of the Three Gorges regular reservoir area. Based on the bulk of measurements, this paper analyzes the evolution of river bed since the impoundment of the Three Gorges reservoir. The result shows that the Three Gorges regular reservoir area is not the whole river siltation, but presents＂point＂ or＂segment＂ decentralized distribution of siltation. Channel geometry shares a close relationship with sedimentation accumulation distribution and siltation intensity, and siltation plane is mainly distributed in wide reaches, bend convex bank below, deep trough and other parts.Siltation intensity in river gully section is relatively large, but it is smaller and even scoured in small narrow section.