STUDY ON EFFECTS OF ARASE DAM REMOVAL ON RIVER BED,FLOW STRUCTURE AND RIVER ENVIRONMENT

2016 Fiscal Year Final Research Report

• Project/Area Number: 26420502
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Hydraulic engineering
• Research Institution: Kumamoto University
• Principal Investigator: OHMOTO TERUNORI 熊本大学, 大学院先端科学研究部(工), 教授 (30150494)
• Project Period (FY): 2014-04-01 – 2017-03-31
• Keywords: ダム撤去 / 河床変動 / 土砂水理学 / 流れの三次元構造 / 砂州 / 超音波流速計 / 河川環境 / 二次流

Outline of Final Research Achievements

Focusing on the river channel downstream of the Arase Dam, whose removal began in September, 2012, this study looks at the sandbar behavior over the years before the dam removal began and tries to elucidate the structure of fine sediment deposits.　In addition, scouring or depositing downstream of submerged dams or weirs with an opening is a sediment phenomena resulting from the interaction of the three-dimensional turbulent flow field around the structure and the moveable sand bed. This research presents the experimental study on the downstream channel bed due to weir with an opening, paying attention to the effects of relative overflow depth on local scouring around the structure, sand bars and three-dimensional flow patterns. The experimental results show that local scouring and sand bar development downstream of the submerged weirs decrease with relative overflow depth and turn out strongly paired cellular secondary currents.

Free Research Field

工学