TY - JOUR

T1 - Calculating flood probability in Obihiro using a probabilistic method

T2 - incorporating the probability of dike failure with uncertainty

AU - Uemura, Fumihiko

AU - Rongen, Guus

AU - Masuya, Shigekazu

AU - Yoshida, Takatoshi

AU - Yamada, Tomohito J.

PY - 2024

Y1 - 2024

N2 - In Japan, estimating flood risk follows a deterministic approach. A probabilistic risk method, as adapted in the Netherlands, would be better suited for the quantitative evaluation of flood damage. This study applies such a method in Obihiro, Hokkaido, northern island of Japan. We modelled dike failure with the mechanism overtopping. The probability of dike failure is calculated with a Monte Carlo simulation, considering uncertainties in water levels, critical flow velocity, and dike heights. This results in more accurate failure probabilities compared to the deterministic approach. Additionally, we corrected the dike failure probability for upstream dike failures because these reduce downstream water levels. This conditional flood probability is about 1/10th of the independent situation, indicating a significant effect of considering dike failure in dependence on upstream failures.

AB - In Japan, estimating flood risk follows a deterministic approach. A probabilistic risk method, as adapted in the Netherlands, would be better suited for the quantitative evaluation of flood damage. This study applies such a method in Obihiro, Hokkaido, northern island of Japan. We modelled dike failure with the mechanism overtopping. The probability of dike failure is calculated with a Monte Carlo simulation, considering uncertainties in water levels, critical flow velocity, and dike heights. This results in more accurate failure probabilities compared to the deterministic approach. Additionally, we corrected the dike failure probability for upstream dike failures because these reduce downstream water levels. This conditional flood probability is about 1/10th of the independent situation, indicating a significant effect of considering dike failure in dependence on upstream failures.

U2 - 10.5194/piahs-386-69-2024

DO - 10.5194/piahs-386-69-2024

M3 - Conference article

SN - 2199-8981

VL - 386

SP - 69

EP - 74

JO - Proceedings of the International Association of Hydrological Sciences

JF - Proceedings of the International Association of Hydrological Sciences

ER -