4:00 PM - 4:15 PM
[AAS01-09] Impact-Based Typhoon Track Ensemble Forecasting for Hagibis (2019): Effects of Typhoon Tracks and Flood Prevention Infrastructure in Flood Damage Assessment
Keywords:Impact-Based Forecasting, Typhoon Track Ensemble Simulation, Typhoon Hagibis (2019), Flood Damage Assessment
Typhoon Hagibis (2019), one of the most powerful storms to strike Japan in recent years, caused widespread flooding and significant damage. Impact-based forecasting is crucial for planning effective mitigation measures and enhancing future disaster responses. This study employs the Integrated Land Simulator (ILS) coupled with the Weather Research and Forecasting (WRF) Model to evaluate flood damage induced by Typhoon Hagibis.
Our control (c000) simulation successfully reproduced the spatial distribution and intensity of accumulated rainfall and peak river discharge. However, compared to observations, the simulation slightly overestimated rainfall and discharge along the Japan Sea side and underestimated them along the Pacific side. These discrepancies are likely due to a slight (~0.3°) westward shift in the simulated typhoon track during landfall.
To systematically assess the impact of typhoon tracks on flood damage, we conducted ensemble simulations. The e008 simulation (0.8° eastward shift) resulted in the highest flood damage, totaling 2478.7 billion JPY. A westward shift reduced total flood damage across Japan but increased it in southwestern regions, whereas an eastward shift led to an overall decrease in flood damage nationwide.
To further investigate the effects of levees and dams on flood damage, we analyzed the differences of flood damage between simulations with and without these structures. The presence of levees and dams led to an overall reduction in total flood damage across Japan. These findings underscore the critical impact of typhoon tracks and flood prevention infrastructure on flood risk. By simulating various typhoon tracks and assessing the role of flood prevention measures, we can deepen our understanding of flood hazards and strengthen disaster preparedness and mitigation strategies.
Our control (c000) simulation successfully reproduced the spatial distribution and intensity of accumulated rainfall and peak river discharge. However, compared to observations, the simulation slightly overestimated rainfall and discharge along the Japan Sea side and underestimated them along the Pacific side. These discrepancies are likely due to a slight (~0.3°) westward shift in the simulated typhoon track during landfall.
To systematically assess the impact of typhoon tracks on flood damage, we conducted ensemble simulations. The e008 simulation (0.8° eastward shift) resulted in the highest flood damage, totaling 2478.7 billion JPY. A westward shift reduced total flood damage across Japan but increased it in southwestern regions, whereas an eastward shift led to an overall decrease in flood damage nationwide.
To further investigate the effects of levees and dams on flood damage, we analyzed the differences of flood damage between simulations with and without these structures. The presence of levees and dams led to an overall reduction in total flood damage across Japan. These findings underscore the critical impact of typhoon tracks and flood prevention infrastructure on flood risk. By simulating various typhoon tracks and assessing the role of flood prevention measures, we can deepen our understanding of flood hazards and strengthen disaster preparedness and mitigation strategies.