Study on Deformation Process of Sand Bars at River Mouth

河口沙坝变形过程研究

基本信息

批准号：
62460160
负责人：
KITAURA Masaru
金额：
$ 2.18万
依托单位：
Kanazawa University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (B)
财政年份：
1987
资助国家：
日本
起止时间：
1987 至 1988
项目状态：
已结题

项目摘要

At river mouth, sand bar is often formed due to interaction of sediment transport by river flow and that by waves, and it affects the flow capacity of the river severely. Hence, an appropiate modelling of deformation process of sand bar at river mouth is required from the view point of river engineering.As for sediment transport in rivers, effect of unsteadiness and non-uniformity of flow on sediment transport is in particular interesting, and thus a non-eguilibrium transport law has been established to describe transient process of sediment transport under such unsteady nonuniform conditions.Sediment transport by weves is more complicated, but somewhat simplified modelling is required for modelling variation process of river morphology at river mouth. Based on laboratory studies, Ursell number is used to predict the direction of sediment transport, and transport discharge formula using Shields number has been proposed, which is quite similar to that established in river region. In order to evaluate the relation between Shields parameter and the characteristics of waves, applicability of a linear filter method is tested.A relaxation model is proposed to descride deformation process of sand bars at river mouth totally, in which equilibrium section of river mouth is used as a parameter instead of complicated parameters related to transport capacity of flow and waves. Based on the field data of actual rivers, the applicability of the present analytical model for deformation process of sand hars has been inspected.

在河口，由于河流流动和海浪的交通相互作用，通常形成沙杆，并且会严重影响河流的流量。因此，从河流工程的角度来看，需要对河口的沙杆变形过程进行适当的建模。作为河流中的沉积物运输，不稳定的影响和流动对沉积物运输的不均匀性，特别有趣，因此，不再使用这种不均匀的型号的不均匀的型号，以确定了不稳定的不均匀的型号，但要建立了更简单的运输方式在河口的河流形态变化过程中建模是必需的。根据实验室研究，Ursell数量用于预测沉积物传输的方向，并提出了使用盾牌数量的运输排放公式，这与在河流地区建立的相似。为了评估盾牌参数与波的特性之间的关系，测试了线性滤波器方法的适用性。建议完全完全将河口的沙棒的弛豫模型描述出河口的沙杆的变形过程，其中河口的平衡部分用作参数，而不是与流量和波浪运输能力相关的参数。基于实际河流的现场数据，已经检查了当前分析模型在避难的变形过程中的适用性。