Development of rainfall-runoff and flood inundation integrated analysis model and parameter optimization method for basinwide comprehensive flood disaster prevention

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K04277
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 22040:Hydroengineering-related
• Research Institution: Kyushu Institute of Technology
• Principal Investigator: Shige-eda Mirei 九州工業大学, 大学院工学研究院, 准教授 (70380730)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: 流域治水 / 降雨流出・洪水氾濫一体解析モデル / パラメータ最適化 / 令和2年7月豪雨 / 球磨川流域 / 実験

Outline of Final Research Achievements

In this study, two numerical methods were developed for disaster resilience and sustainability of river basins by all. The first method is an integrated rainfall-runoff and flood-inundation numerical model. This model attempts to deal with the surface-to-subsurface flow and flood and inundation flows in a basin in an integrated manner. The model can also capture the behavior of stormwater in the entire basin. The second method was an efficient parameter optimization method using Bayesian estimation methods. The prediction accuracy and validity of these methods were compared with experimental results. These methods were applied to the Kuma River basin during the July 2020 heavy rainfall event. The results showed that these methods could reproduce the observed inundated areas and flood marks in the Kuma River basin. It also showed that the methods were useful for understanding the water balance of the Kuma River basins and its tributary basins.

Free Research Field

数値流体力学

Academic Significance and Societal Importance of the Research Achievements

近年，豪雨による水害が頻発しており，その対策は喫緊の課題である．流域治水はその効果が期待される対策であり，流域治水の治水効果の評価は極めて重要となる．本研究で開発した降雨流出・洪水氾濫一体解析モデルを用いることで，大河川だけでなく中小河川での水害リスクや流域治水対策の治水効果を評価できるようになり，これに加え，気候変動下で降雨量の増加が見込まれる将来に対して，流域レベルでの被害最小化策と効果的な危機管理対策の具体を検討する上で有用な情報を提供できるようになると考えられる．