Author(s): Nozomu Mitsui; Jin Kashiwada; Riku Kubota; Yutaro Omi; Takehiko Ito; Mamoru Tanaka; Yasuo Nihei
Linked Author(s): Mamoru Tanaka, Jin Kashiwada, Yasuo Nihei
Keywords: Flooding RRI model River and flooding flow analysis Lake Inba-numa Road embankment
Abstract: In recent years, floods have become more frequent and severe in Japan, and river basin disaster resilience and sustainability by all (RBDRSA) project is underway to address this issue. For further progress of this project, it is necessary to develop a numerical simulation model which can assess quantitatively flood risks and various flood-control measures. For this, this study proposed a coupled model with RRI (Rainfall-Runoff-Inundation) model and horizontally 2D model (RRI-RF2D) for river and flood flow analysis. In order to check the validity of the present model, we conducted flooding analysis in Takasaki River basin, Chiba prefecture, Japan due to Typhoon Yun-yeung in 2023. The results indicated that the RRI-RF2D model can reproduce acceptably longitudinal distribution of peak water level and flooding area along the Takasaki River, showing the fundamental validity of the present model. The result also showed that the flooding water was appreciably storaged near road embankments across the river. This effect may have ensured the lead time of flooding at downstream of the road embankment, and it suggests that road embankments may play an important role as one of the flood-control measures.
Year: 2025