気候変動による降水量変化が河川流域の流木災害リスクへ与える影響に関する評価  [in Japanese] EVALUATION OF IMPACT OF PRECIPITATION VARIATION DUE TO CLIMATE CHANGE ON WOODY DEBRIS HAZARD RISK IN A RIVER  [in Japanese]

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Abstract

平成24年と同29年の九州北部豪雨で被災した花月川流域を対象に,矢野ら(2016)により開発された流域全体の流木発生ポテンシャルと橋梁位置での相対的流木災害リスクの評価法に斜面の地質と降雨量から斜面崩壊危険度を評価するモデルを組み込む改良を試みた.また,温暖化後の状況を想定し,1時間雨量の確率年ごとの流木災害リスク評価を行い,流木発生に対する温暖化の影響評価を実施した.その結果,温暖化の進行に伴う降雨強度の増加が流域の流木発生ポテンシャルと橋梁の流木災害リスクをともに増加させるが,その変化傾向は異なることが明らかとなった.

 In this paper, we attempted to refine the evaluation method of drift woods generation potencial and woddy debris hazard risk at a bridge developed by Yano et al. (2016) in the Kagetsu River, where record breaking big floods attacked due to both of heavy rain events in 2012 and 2017. In the new method, information of geography, geology, forest, dimension of a bridge is included. As a result of application of the new method, the followings are clarified: 1) Impact of precipitation variation due to climate change on drift woods generation potencial can be evaluated. Also, its impact on woody debris hazard risk for a bridge can be clarified; and 2) Those impacts show different trend for precipitation variation.

Journal

  • Journal of Japan Society of Civil Engineers, Ser. B1 (Hydraulic Engineering)

    Journal of Japan Society of Civil Engineers, Ser. B1 (Hydraulic Engineering) 74(4), I_1327-I_1332, 2018

    Japan Society of Civil Engineers

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