河床演变阶段模型及其在三门峡水库和渭河下游的应用

Alluvial phase space diagram and its application to the Sanmenxia Reservoir and the lower Wei River

基于河床冲淤和横断面面积变化,提出描述河道冲淤及垂向和横向调整的河床演变阶段模型,将该模型应用于1960-2017年三门峡库区和渭河下游河道的演变过程,结果表明,该模型可反映河道冲淤的时空变化特征,在溯源冲刷阶段,库区及渭河下游下段由下游向上游依次呈现“河床冲刷下切”、“河道冲刷展宽”、“河道淤积展宽”三个演变阶段,这一空间分布与河道沿程冲刷的演变阶段分布相反,反映了沿程与溯源冲刷特征的差异及河道横向可动性的影响。

Based on the vertical and cross-sectional area changes of river channels, this paper proposes an alluvial phase space diagram(APSD), which describes the erosion and aggradation, vertical and lateral adjustment characteristics of river channels. The proposed method was applied to the channels in the Sanmenxia Reservoir and the Lower Wei River during different periods in 1960-2017. Results show that the model could reflect the spatial and temporal characteristics of channel scour and aggradation. During retrogressive erosion processes, the stages of channel incision, degradation and widening, and aggradation and widening tended to occur in a sequence in the upstream direction. This spatial distribution was contrary to that in progressive erosion, reflecting the different characteristics of retrogressive and progressive erosion and the impact of channel lateral activity.