COMPARISON OF TWO NUMERICAL MODELS BY USING A CASE STUDY OF 2014 DEBRIS FLOW DISASTER IN HIROSHIMA.

Código

III-END0096

Autores

Alessandro Gustavo Franck, Masato Kobiyama

Tema

10. Movimentos de massa

Resumo

Debris flows are common in mountain regions, being severe natural hazards due to their high velocity, travel distance and huge destructive energy. Numerical simulation has been widely applied to assess debris flow hazards, there are various numerical models, among which the Hyper KANAKO (HK) and the Morpho 2DH (M2DH). Several authors have already proposed comparative analyses between debris flow models, therefore, the objective of the present study was to compare the performances of two models HK and M2DH by using one debris flow disaster. The study area was the Asa-Kita ward in Hiroshima city. In this ward, in August 2014, several mass movements were triggered after a torrential rainfall that exceeded 100?mm/h, causing a large number of debris flows and 74 dead. To perform the simulations, we used a DTM (5-m resolution) freely available on the internet, and the priority was to ensure that both models had as many equal parameters as possible, so that the comparison was fairer. The simulation results show significant differences between the models. The main difference is the maximum depth in the front of debris flow during each simulation step presented by the two models, where this depth in the HK is much smaller than in the M2DH during most of the time. In general, Morpho 2DH presented some advantages over Hyper KANAKO. There was also a certain difference between the results presented by the two models. To better assess these differences and the limitations of each model, further investigations are needed.