Method for predicting sediment runoff including sediment storing mechanism in stream channels

包括河道淤积机制的泥沙径流预测方法

• 批准号: 13450205
• 负责人: EGASHIRA Shinji
• 金额: $ 5.06万
• 依托单位: Ritsumeikan University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2001
• 资助国家: 日本
• 起止时间: 2001 至 2003
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-13450205/
• 关键词: sediment runoff model; sediment yield and runoff; rainfall runoff; debris flow; sediment transportation; bed-loads; suspended loads; wash loads; 降雨流出; ウオッシュロード; ウォッシュロード

To develop a method for predicting sediment runoff at any cross section of stream channels in a drainage basin, the research was conducted with three sub-topics; 1. density of landslides' occurrences and transformation rate of landslides to debris flow, 2. sediment storing mechanism in channel reach due to sediment transportation by debris flow and 3. development of a method for predicting sediment runoff based on Egashira's method and the results of above sub-topics. The results are summarized as follows.1. The density of landslides occurrences caused by heavy rainfall is closely related to surface and intermediate flows on mountain slopes and can be explained using parameters such as the occupied ratio of surface and intermediate flows, slope gradient and thickness of surface soil layer. In Japanese topographic conditions, landslides more than eighty percent are transformed into debris flows through their run-out processes.2. Formulas for mass conservation with respect to total sediment as well as to each grain size class are proposed to treat an abnormal sediment runoff problem which takes place in stream channels where a large amount of sediment is transported by debris flows.3. A method is proposed for predicting sediment runoff due to rainfall, which is composed of drainage-and channel-model, sediment transport model and rainfall runoff model and can evaluate bed-loads, suspended loads and wash loads. To test validity of the method, predicted results are compared to the observed data for annual reservoir sedimentation and wash loads during several floods in the upper drainage of Kumano river, and accord well with the corresponding data.

为了开发一种预测流域内任意断面河道泥沙径流的方法，本研究分为三个子主题；1. 2.滑坡发生密度与滑坡向泥石流转化速率；2 .泥石流输沙作用下河道段泥沙淤积机制；基于Egashira的方法和上述子主题的结果开发泥沙径流预测方法。结果总结如下：1。强降雨引起的山体滑坡发生密度与坡面和中间流密切相关，可以用坡面和中间流占比、坡度和表土层厚度等参数来解释。在日本的地形条件下，80%以上的山体滑坡都是通过径流过程转化为泥石流的。提出了总沙量和各粒度级的质量守恒公式，用于处理泥石流搬运大量泥沙的河道中发生的异常泥沙径流问题。提出了一种预测降雨径流的方法，该方法由排水-河道模型、输沙模型和降雨径流模型组成，可对河床荷载、悬浮荷载和冲刷荷载进行评估。为了验证该方法的有效性，将预测结果与熊野河上游几次洪水的年水库沉积和冲刷量观测数据进行了比较，结果与实测数据吻合较好。

项目成果

Takahiro Itoh, Kuniaki Miyamoto, Shinji Egashira: "Numerical simulation of debris flow over erodible bed"Proceedings of the 3rd International Conference on Debris-Flow Hazards Mitigation. 457-468 (2003)

Takahiro Itoh、Kuniaki Miyamoto、Shinji Egashira：“侵蚀床上泥石流数值模拟”第三届国际泥石流灾害减缓会议论文集。

Rabindra Osti, Shinji Egashira, Takahiro Itoh: "Prediction of 1999-San Julian debris flows based on dependent and independent occurrences"Annual Journal of Hydraulic Engineering. Vol.48 (2). 913-918 (2004)

Rabindra Osti、Shinji Egashira、Takahiro Itoh：“基于相关和独立事件的 1999 年圣朱利安泥石流预测”水利工程年度杂志。

江頭進治, 伊藤隆郭: "河道堆積物の生成機構を考慮した土砂流出予測法の開発"平成15年度 砂防地すべり技術研究成果報告会講演論文集. 33-46 (2003)

Shinji Egashira，Takakaku Ito：“考虑河道沉积物形成机制的沉积物径流预测方法的开发”2003年Sabo滑坡技术研究成果会议论文集33-46（2003年）。

Shinji Egashira, Hiroji Nakagawa, Takahiro Itoh, Rabindra Osti: "Theoretical tools for analyzing sediment hazard countermeasures"Proceedings of the International Civil Engineering Conference on Sustainable Development in the 21st Centiry (Nairobi, Kenya).

Shinji Egashira、Hiroji Nakakawa、Takahiro Itoh、Rabindra Osti：“分析沉积物危害对策的理论工具”21 世纪可持续发展国际土木工程会议论文集（肯尼亚内罗毕）。

竹林洋史・江頭進治・岡部健士: "混合砂河床における網状流路の数値解析"水工学論文集. 第47巻. 631-636 (2003)

Hiroshi Takebayashi、Shinji Egashira 和 Kenji Okabe：“混合沙河床中网状河道的数值分析”，《水利工程杂志》，第 47 卷，631-636（2003 年）。