Study on the Excessive Growth of Reverine Trees and Its Effects on Morphological Processes in Gravel-Bed River

砾石床河中Reverine树的过度生长及其对形态过程的影响研究

基本信息

批准号：
10650499
负责人：
SHIMIZU Yoshihiko
金额：
$ 2.11万
依托单位：
Gunma University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1998
资助国家：
日本
起止时间：
1998 至 1999
项目状态：
已结题

项目摘要

Recently reverine trees in the course of gravel bed-river have extremely increased and enlarged their covered-area over bars and flood plain. Such a situation brings about problems of river management for the environmental aspects as well as the safety of rivers against flood. In order to clarify such problems, we should get the knowledge about how the instream vegetation grow up and expand their covered zones in gravel-bed river.In this study, the field surveys were carried out in the upstream reach of the river Watarase which has the averaged bed slope of about 1/150 and has the characteristics of the segment-1 reach. The surveys suggest that the groves of Robinia pseudo-acacia expanded over bars and flood plains with the surface layer of the fine sand. This layer is formed by the deposition of fine sand(0.5mm-1.0mm) and its resources might originate from bed materials in the main channel. It is significant factor for the growth of Robinia pseudo-acacia and the formation of trees expanded area. The results also propose a scenario of the formation of the reverine trees expansion in gravel-bed river. Furthermore, the applicability of a 2D-numerical flow model including vegetation drag effect is verified for the upstream reach of the river Watarase which has the characteristics of the segment-1 reach with the excessive reverine trees. Calculated results are compared with the results obtained by the observation after flood and predict an increase in water-level depending on the vegetation density and predict morphological processes in gravel-bed river with the excessive reverine trees.

最近，在砾石床河过程中，崇拜树已经极大地增加，并在酒吧和洪水平原上扩大了覆盖区。这种情况给环境方面的河流管理问题带来了问题，以及河流的安全侵害洪水。为了澄清此类问题，我们应该了解有关乐器植被如何成长和扩展其在砾石床的覆盖区域的知识。在这项研究中，在河水河流的上游范围内进行了野外调查，该河水的平均床坡度约为1/150，并且具有分段1范围的特征。这些调查表明，罗比尼亚伪 - 阿卡西亚的树林在带有细沙的表面层的条形和洪水平原上扩展。该层是由细砂（0.5mm-1.0mm）的沉积形成的，其资源可能起源于主通道中的床材料。这是罗比尼亚伪acacia的生长和树木膨胀区域的重要因素。结果还提出了一个场景，即砾石河河中淡树膨胀的形成。此外，还验证了包括植被阻力效应的2D数字流量模型的适用性，以实现河水酶的上游覆盖率，该河流范围具有段-1的特征，并具有过多的振动树。将计算的结果与通过洪水后观察结果获得的结果进行了比较，并根据植被密度预测水位的增加，并预测过多的振动林树的碎石河河中的形态学过程。