FLOOD INUNDATION MAPPING BY ASSIMILATING LOCAL INFORMATION -PRACTICAL IMPROVEMENT AND APPLICATION TO THE ODA RIVER FLOODING IN JULY 2017

For effective emergency responses to flood disasters, estimating inundation depth distributions is crucial on the real-time basis. In the previous studies, the authors proposed a method to achieve this objective by assimilating preliminary conducted multiple inundation simulations and local flood related information. This study further improves the applicability of the proposed method with respect to utilzing existing inundation simulations conducted for hazard mapping in all over Japan. Based on the application to the recent flood disaster occurred in the lower part of the Odagawa River basin in Okayama Prefecture, this study showed the reasonable performance for simulating inundation depth distributions and estimating flood volumes even with limited local information obtained at four to eight points with the relative errors of 7% to 3% in the flood volume estimations.