Run-off process of suspended sediment in mountain rivers

山区河流悬浮泥沙径流过程

基本信息

批准号：
09460069
负责人：
FUJITA Masaharu
金额：
$ 2.88万
依托单位：
KYOTO UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
1997
资助国家：
日本
起止时间：
1997 至 1998
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09460069/
关键词：
Suspended load Mountain river Runoff process Diffusion theory Diffusion equation Source term Field observation Flood 土砂流出流砂濃度分布乱流

项目摘要

1. Stream flows and runoff process of suspended sedimentWe observed suspended sediment concentration, flow discharge and rainfall intensity simultaneously in the Takahara river basin and discussed their relationship. As a result, the following matters were found out. Suspended load concentration is strongly dependent on rainfall intensity, but the relation between them is not unique because the soil on slopes is quickly washed out. The relation between flow discharge and suspended load concentration is not also unique because of the same reason. This change in the situation of source areas should be studied in future.2. Diffusion theory of suspended sedimentAccording to previous study, the diffusion equation of suspended sediment which is generally used cannot explain a suspended sediment concentration in a steep channel with a large roughness without the much larger diffusion coefficient In this paper, we have presented a diffusion equation with a source term and shown the concentration in the above-mentioned channel can be expressed by means of the equation with the ordinary diffusion coefficient.3. Modeling of runoff process of suspended sedimentIf the boundary condition of suspended load concentration is given, the runoff process of suspended sediment in river systems can be analyzed by means of the presented diffusion theory. However, the boundary condition can not be easily evaluated because the sediment production process is too complex. We will study more about this point.

1。悬浮Sedimentwe的溪流流和径流过程观察到悬浮的沉积物浓度，流量排出和降雨强度在高君河盆地同时进行，并讨论了它们的关系。结果，发现了以下问题。悬浮的负载浓度很大程度上取决于降雨强度，但是它们之间的关系并不是唯一的，因为斜坡上的土壤迅速被洗净。由于存在相同的原因，流量排出和悬浮负荷浓度之间的关系也不是唯一的。将来应研究来源区域情况的这种变化2。悬浮沉积物对先前研究的扩散理论，通常使用的悬浮沉积物的扩散方程无法解释悬挂的沉积物浓度，在陡峭的通道中具有较大粗糙度的悬浮沉积物浓度，而本文中的扩散系数较大，我们已经用源术语表示扩散方程，并在上述频道中表现出频率的浓度，可以通过等式表达浓度。悬浮式沉积物的径流过程的建模给出了悬浮载荷浓度的边界条件，可以通过提出的扩散理论分析河流系统中悬浮沉积物的径流过程。但是，由于沉积物生产过程太复杂，因此无法轻易评估边界条件。我们将更多地研究这一点。