河床结构强度及其与水流能量关系的定量研究

Quantified study on the riverbed structure intensity and its relationship with stream power

山区河流在长期河床演变过程中常发育一定的河床结构,其分布与环境条件之间存在密切关系。本文设计使用了河床结构的精确定量描述方法,在天然河流测量工作的基础上,对河床结构的发育分布规律进行了研究。经统计发现,动力平衡条件下河床结构强度Sp值与其消耗的单宽水流能量p成正比。这反映出河床结构强度的分布主要与水力条件相关。若河道中河床结构不足以消耗水流能量,则河流不平衡,多余的能量将侵蚀冲刷床面。此外,还探讨了包含推移质在内的统一耗能模型。

Streambed structures were developed in many mountain rivers as a result of fluvial morphology and their distributions were relevant with environmental conditions.This paper used a new accurate method and studied the distributions of such structures based on the field data of natural rivers.The results indicate that for a river in dynamic equilibrium,the intensity Sp of its streambed structures is proportional to its unit width stream power p consumed by the structures.This means that the distributions are relevant to hydraulic conditions.If the structures are not able to consume up the total power p,the river is in non-equilibrium status and its excess power will cause erosion of streambed.The unified power consumption model including bedload movement was also discussed in this paper.