Proposal of a model for simulation of debris flow on basin level with different rheology approaches and flow directions algorithms

Código

III-END0065

Autores

Leonardo Rodolfo Paul, Gean Paulo Michel, Heron Schwarz, Clarissa Guerra Salvador, Bruno Henrique Abatti

Tema

10. Movimentos de massa

Resumo

Debris flows are mass movements with high reach and velocity, having the capacity to cause social, economic and environmental loss. Thus, it is important to understand this phenomenon and to predict affected areas in order to prevent disasters driven by debris flows. To this end, physically based models that seek to represent debris flow processes and dynamics can be utilized. In this regard, this study proposes a debris flow simulation model that requires few inputs and is capable to provide information about reach, velocity and depth of deposition. The model is a coupling of a mass balance equation and a flow direction algorithm. The study was undertaken at rio Mascarada (RS) basin, in a 3 km² area, simulating a debris flows event occurred in January, 2017. The behavior of different flow direction algorithms (D8, D-inf, Freeman?s MFD) and different rheological approaches (Newtonian, dilatant, Bingham plastic and Herschel-Bulkley) was tested. MFD, associated to a dilatant rheology and kinematic viscosity of 0.5 m²/s, was the most adequate flow direction algorithm to represent debris flow. In general, the model properly represented debris flow reach. Therefore, the proposed model sets up as an easy-to-use tool to assess debris flow susceptibility in areas with low data availability.