Assessment of landslides travel lengths within a tropical mountainous region using two-dimentional multiphase modeling

Different flow-type mass movements such as debris flows, mudflows and hyper-concentrated flows have had catastrophic consequences in history. Estimating the travel length of these movements is critical for land planning, and different methodologies have been developed to understand the dynamics of these processes. These methodologies are classified into two main groups, empirical/statistical models and analytical/deterministic models. This work analyzed travel lengths of flow-type mass movements located in a tropical mountainous region of Colombia using the two-dimensional multiphase analytical model r.avaflow. Even though the model was run under limited information conditions, we were able to obtain sound results for key processes such as drag, deposition, detention, and phase transformations, by determining values of physical parameters that characterize specific events. These results may serve as a basis in advancing the understanding of the dynamics and prediction of this type of natural phenomena in the region and thereby, contributing to the continuous improvement of risk management and territorial planning. Preliminary results show that the numerical models present greater sensitivity to the density, internal friction angle, and basal friction angle parameters. We found congruence between the travel distances observed in the field with those calculated with the two-dimensional model through a parameter calibration process.