Sameh A. Kantoush

ヨーロッパアルプス地域のダム貯水池は，流入河川がもたらす土砂の堆積作用によって，その持続可能性が著しく脅かされている。このような貯水池に対する土砂管理計画を，一般化された基準や方策で記述することはなかなか難しい。本報では，日本とアルプス地域のダムにおける土砂堆積に伴うリスクを定義し，これを適切に計測することを目的としている。特に，総合土砂管理の導入によって，水資源の持続的利用，生物環境の保全，さらには，人間と自然の調和を図るために，健全な河川流域を如何に維持するかが最終的な目的である。土砂管理を成功させるためには，河川マネジメントから根本的に変える必要があり，これには，いくつかの対策の組み合わせにより，ダムを通過する水量と土砂量をバランスさせることが重要である。アルプスの大規模貯水池では，密度流が細粒土砂を高濃度で輸送する現象がしばしば観察され，これを適切に制御することが求められる。

Between 2015 and 2016, Vietnamese Mekong Delta (VMD) has undergone the most severe drought event over the last 90 years, causing damages to agriculture, aquaculture, and fresh water suply. Moreover, upstream Mekong River development by constructing hydropower dams will magnify the severity to the region. This research therefore aims at summarizing some damaged information caused by drought event 2015-2016 and analyzing the impacts of eleven proposed mainstream dams in Thailand, Lao PDR, and Camb

The worst enemy of sustainable use of reservoirs is sedimentation. Often the main silting process is the result of settling down of suspended sediments. In shallow reservoirs the flow pattern and the sediment deposition processes are strongly influenced by the reservoir geometry. The trap efficiency of a shallow reservoir depends on the characteristics of the inflowing sediments and the retention time of the water in the reservoir, which in turn are controlled by the reservoir geometry. With the

Depositional and flow patterns are first described to gain an understanding of the erosion patterns during hydraulic flushing in a reservoir. Considering the importance of this issue, two modes of flushing operation for control of sedimentation were performed in several experiments with different reservoir geometries. In order to investigate the effect of flushing and the effectiveness during free and drawdown flows, ten experiments have been conducted. The final bed morphology formed previously

This paper evaluates the performance of the sediment bypass tunnel that diverts the suspended sediment from Lake Miwa to downstream reaches below Miwa dam. In such a complex processes during bypassing, it is difficult to predict the sediment bypassed efficiency numerically. Therefore, the digital image techniques were developed and implemented to measure the flow pattern and suspended sediment concentration SSC for the first time in Miwa dam. Where, field measurements were conducted during flood