Development of Risk Map of Tropical Cyclone Caused Heavy Rainfall in Japan for Adaptation Measure

2021 Fiscal Year Final Research Report

• Project/Area Number: 20K14832
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 22040:Hydroengineering-related
• Research Institution: Public Works Research Institute (2021); Hokkaido University (2020)
• Principal Investigator: Hoshino Tsuyoshi 国立研究開発法人土木研究所, 土木研究所(寒地土木研究所), 研究員 (40750625)
• Project Period (FY): 2020-04-01 – 2022-03-31
• Keywords: 台風 / 大雨 / 令和元年台風19号 / d4PDF / 気候変動 / 台風経路 / アンサンブル気候データ / 大雨リスク

Outline of Final Research Achievements

The characteristics of heavy rainfall caused by tropical cyclones were examined based on the relationship between tropical cyclone tracks and rainfall intensity. Ensemble climate data, consisting of several thousand years of data in total, was used to clarify the relationship between the location of tropical cyclones and rainfall intensity in the basin. As a result, a dangerous area was identified where the typhoon would be located over the river basins in Japan. In addition, the rainfall amounts when the typhoon path is shifted from east to west were determined from ensemble climate data by focusing on Typhoon Hagibis (2019). Furthermore, a classification method for spatiotemporal rainfall patterns was developed. The relationship between the classified heavy rainfall patterns and typhoon paths was clarified. These results are expected to contribute significantly to the study of future flood control measures using ensemble climate data.

Free Research Field

気象学、水文学

Academic Significance and Societal Importance of the Research Achievements

台風による大雨は甚大な被害をもたらす上、気候変動による雨量の増大も危惧されることから台風による大雨の特徴の理解は重要な過大である。本研究では台風の位置と流域スケールの降雨強度の関係を5km解像度のアンサンブル気候データの台風経路と大雨の情報を用いることにより明らかにした。また、アンサンブル気候データを活用した過去の台風がもたらし得た降雨量やその温暖化応答の推定手法を初めて提案した。さらに、本研究では災害のパターンや規模に直結する降雨の時空間的なパターンの分類手法を提案することで、台風経路別の災害シナリオを検討可能とするなど、新しい治水対策の検討につながる成果が得られた。