水沙交界面冲刷与淤积的同步性探讨

A Study on the Mutually Exclusive of Erosion and Deposition at the Water-sediment Interface

关键词:  水沙交界面  近底泥沙通量  冲刷与淤积  冲刷与淤积的同步性  再悬浮过程

Key words:  water-sediment interface  sediment flux near the bed  erosion and deposition  simultaneous of erosion and deposition  resuspension

摘要:

在悬沙与底床泥沙的交换过程中,冲刷的同时是否伴随着悬沙的淤积,这对于了解水沙交界面泥沙通量至关重要,冲刷和淤积的具体过程值得进一步探讨。本文分析总结了几个系列实验,包括经典的Krone、Mehta、Partheniades等的实验,并从近底泥沙通量的几个不同提法出发,分析各自所描述的冲刷和淤积过程,结合Sanford等在一些河口、海湾的分析,认为近底水沙交界面附近,不论非粘性粗颗粒泥沙还是粘性细颗粒泥沙,冲刷和淤积同时发生。利用再悬浮过程解释细颗粒泥沙冲刷与淤积过程同时发生的问题,从而进一步完善近底泥沙交换现象的物理图谱。

Abstract:

During the exchange process of suspended sediment and bed sediment, whether the suspended sediment deposits when erosion occurs? It's very important to understand the sediment flux at the water-sand interface, so the process of erosion and deposition deserves further exploration.This article analyzed and summarized several series of experiments, including the classic Krone, Mehta, Partheniades and other experiments.Based on the several different formulations of the sediment flux near bed, the process of erosion and deposition was analyzed.Combined some analyses at the estuary and bay, it concluded that the erosion and deposition occurred simultaneous at the water-sediment interface for both non-cohesive and cohesive sediment.The resuspension process was used to explain the simultaneous occurrence of fine sediment flushing and sedimentation processe, thus further perfecting the physical map of sediment exchange in the near-end sediment.