Flood prediction with levee breach and evacuation route search method for small and medium rivers of insufficient hydraulic observation data

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K05047
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 25030:Disaster prevention engineering-related
• Research Institution: Okayama University
• Principal Investigator: Maeno Shiro 岡山大学, 環境生命科学学域, 特任教授 (20157150)
• Co-Investigator(Kenkyū-buntansha): 赤穂 良輔 岡山大学, 環境生命科学研究科, 准教授 (90599333)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: 水防災 / 堤防決壊予測 / 被害予測 / 内外水位差 / 避難経路 / 氾濫解析

Outline of Final Research Achievements

Due to global warming effect, severe flood damage has frequently occurred especially in small and medium rivers. Therefore, it is important to carry out flood analysis in advance and identify areas at high risk of inundation, and indicate evacuation routes during flooding beforehand. However, because the observation data necessary for accurate flood analysis is scarce for small and medium rivers, so, it is an urgent issue to improve the analysis accuracy. In this study, we clarified how to give an effective upstream end boundary conditions and how to give a levee crest height to improve the accuracy of flood analysis of small and medium rivers. In addition, it was shown that an appropriate evacuation start time can be shown by considering the evacuation time and evacuation route in the event of a levee failure.

Free Research Field

河川工学

Academic Significance and Societal Importance of the Research Achievements

近年堤防決壊を伴う大規模水害が頻発しており，特に中小河川の被害が大きい．中小河川は観測データが少ないため被害を予測するための精度良い氾濫解析が困難である．本研究で示した精度向上のための手法を用いることで多くの中小河川で氾濫解析の精度を向上させることが期待出来る．また，提案した堤防決壊が生じる箇所を推定する簡易な手法は我が国の多くの中小河川に適用できるため堤防の弱点箇所を抽出し優先的に堤防強化を図ることができる．さらに，氾濫時に時間的に変化する浸水深や歩行速度を考慮した避難経路を示すことで適切な避難開始時刻や最適な避難経路を示すことができるため防災面での工学的，社会的意義は大きい．