研究課題
Installation of additional monitoring systems of two IP Cameras, one on the bridge and one on the left bank of the river, for real-time sediment erosion patterns at the sediment replenishment site and surface flow velocities near the SR site. Additionally, install one turbidity meter to measure suspended sediment concentration. In total, four times field surveys at Naka River for measuring Grain Size Distribution (GSD) along four gravel bars, a drone for the sediment replenishment site, and morphological changes. Field visit and data collection of Buech River in France. Develop a comprehensive assessment method for sediment replenishment in the Naka and Buch Rivers, considering the erosion efficiency of replenished sediment and downstream eco-hydro-geomorphological impacts. We established a two-dimensional model to simulate the hydro-morphological changes with the implementation of SR in the Naka River based on TELEMAC-2D coupled with Gaia. The model was then calibrated and validated for previous flood events and the 2022 flood event. Then, based on the calibrated model, we utilized it to simulate several scenarios to investigate the optimization strategies of SR by considering replenishment erosion and downstream responses. There are rare significant floods that occurred recently in the Nagayasuguchi dam, indicating that an increase in flushing magnitude is difficult to implement under dam management.
2: おおむね順調に進展している
A Ph.D. study has been completed based on this project. We conducted field surveys in the Buech River in France and collected data on river cross-section, grain size distribution, and ecological indicators. Furthermore, we calibrated and validated the TELEMAC2D model and started the sensitivity analysis for optimal parameter selection. We compared Naka and Buech Rivers based on the developed comprehensive assessment approach. We have published this work and presented it at various conferences and meetings. We investigated the impacts of the flushing flow and the sediment volumes. We designed three scenarios for double flood pulses and additional sediment replenishment arrangements.
Based on the well-developed 2D model, we will optimize the sediment replenishment works in the Naka River. We will propose a guideline for sediment replenishment implementation. The downstream morpho-ecology requires optimal flushing flow, volume, and sediment supply from the SR site to maintain its positive functionality. We will check the feasibility of implementing the double stockpiles at Kohama.
すべて 2022
すべて 雑誌論文 (4件) (うち国際共著 4件、 査読あり 4件、 オープンアクセス 3件) 学会発表 (2件) (うち国際学会 1件、 招待講演 1件)
Journal of Hydrology
巻: 617 ページ: 128-892
10.1016/j.jhydrol.2022.128982
Geomorphology
巻: 413(15) ページ: 108-368
10.1016/j.geomorph.2022.108368
Hydrological Processes
巻: 37(3) ページ: 148-34
10.1002/hyp.14834
Water
巻: 14 ページ: 15-88
10.3390/w14101588
