Access count of this item: 76

Files in This Item:
File Description SizeFormat 
20180330_kyusyu_63.pdf1.2 MBAdobe PDFView/Open
Title: <治水>治水面から見た被害の概要と着目点
Authors: 角, 哲也  KAKEN_name
Author's alias: SUMI, Tetsuya
Keywords: Characteristice of flood disasters
Rainfall statics
Rainfall-runoff model
Rainfall induced land slides
Morphological effects on flood inundation
Trapping of floating debris in reservoirs and its effect on flood risk reduction downstream
Issue Date: 30-Mar-2018
Publisher: 京都大学防災研究所
Journal title: 2017年九州北部豪雨災害調査報告書
Start page: 63
End page: 67
Abstract: 本稿は2017年九州北部豪雨を対象に, 防災研究所内部で構成された研究グループのうち, 治水面から見た被害の概要と着目点, さらには, これを踏まえた治水グループの取組みを概説する. 着目点は, 1) 筑後川北側はこれまでの災害未経験地域であったこと, 2)日田の林業地域における山林崩壊・河岸侵食により大量の流木が発生したこと, 3)風化花崗岩地域から大量の土砂流出が発生したこと, 4)洪水・土砂・流木の複合災害の形態を示していること, 5)ダムの無い小河川では, 洪水が短期間にそのまま流出して災害化したこと, 6) 多くのため池のうち, 決壊で被害拡大がクローズアップした一方で, 決壊せずに, むしろ, 流木・土砂を受け止めて被害防止に貢献したものもあること, 7)砂防ダムでは土砂のみではなく, 流木を受け止めたものもあること, 8)貯水ダム(寺内ダム)では, 洪水・土砂・流木の3要素をコントロールして, 絶大な役割を働き果たし, ダムが無ければ下流で大きな氾濫が発生していた可能性があること, などである. こうした被害の特徴を踏まえて, 降雨の極値統計と流出・氾濫解析, 豪雨における斜面崩壊と洪水の統合解析, 土砂流出による流路・河床変動と洪水氾濫特性, 下流域における土砂・氾濫解析, ダムにおける流木捕捉効果と下流洪水リスク軽減効果の各観点から報告を行う.
This manuscript reports the summary of flood damages and each focusing points that the flood control research group in the Disaster Prevention Research Institute, Kyoto University. Selected focus points are as follows: 1) the north side of the Chikugo River was a disaster inexperienced area so far, 2) a large amount of driftwood occurred due to forest collapse and river bank erosion in Hita's forestry area, 3) large amount of sediment discharged from the weathered granite area, 4) it is showing the form of complex disaster of flood, sediment and driftwood, 5) in small rivers without dam, floods flowed out as it is in a short period and caused disasters, 6) out of many irrigation ponds, some expanded disaster damages because of pond collapses, whereas, without collapses, some reduced damages downstream by trapping driftwood and sediment, 7) some Sabo dams trapped not only sediment but also some driftwoods 8) In the dam reservoir, Teraiuchi dam has played an enormous role by controlling three elements of flood, sediment and driftwood, and large flooding possibly occurred downstream without dam. Based on the characteristics of such damage, we reported from the viewpoints of extreme value statistics of rainfall and runoff/flood analysis, integrated analysis of slope failures and floods in heavy rainfall, flow path/bed fluctuation due to sediment discharge and flood damage characteristics, sediment and flooding analysis in the downstream area, the driftwood trapping effect and the downstream flood risk mitigation effect in the dam.
Related Link:
Appears in Collections:2017年九州北部豪雨災害調査報告書

Show full item record

Export to RefWorks

Export Format: 

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.