Runout analyses using 2014 Oso landslide

Abstract

Understanding the runout of slope failures is important for hazard identification, risk assessments, and disaster prevention. This study evaluates the accuracy of three runout software packages, DAN3D, Anura3D, and FLO-2D, for modeling the runout of the 2014 Oso landslide and investigates the viability of predicting the runout of other landslides and slope failures under similar conditions. The Oso landslide runout analyses using Anura3D and FLO-2D conducted for this study adopt the geotechnical conditions and failure mechanism reported by Stark and his colleagues in 2017. Together with DAN3D and Anura3D modeling reviewed from previous studies, the accuracy and applicability of these runout models are assessed using field observations. These analyses show the importance of (i) using a digital terrain model in the runout analysis, (ii) modeling field representative shear strength properties and failure mechanisms, and (iii) predicting runout distance, splash height, and duration for risk assessments and to improve public safety for this and other slopes.