Simulation of debris flows in the Central Andes based on Open Source GIS: Possibilities, limitations, and parameter sensitivity

Abstract

A GIS-based model framework, designed as a raster module for the OpenSource software GRASS, was developed for simulating the mobilization and motion ofdebris flows triggered by rainfall. Designed for study areas up to few square kilometres, thetool combines deterministic and empirical model components for infiltration and surfacerunoff, detachment and sediment transport, slope stability, debris flow mobilization, andtravel distance and deposition. The model framework was applied to selected study areasalong the international road from Mendoza (Argentina) to Central Chile. The inputparameters were investigated at the local scale. The model was run for a number of rainfallscenarios and evaluated using field observations and historical archives in combinationwith meteorological data. The sensitivity of the model to a set of key parameters wastested. The major scope of the paper is to highlight the capabilities of the model—and ofthis type of models in general—as well as its limitations and possible solutions.