Numerical Modelling and Sensitivity Analysis of the Pitztal Valley Debris Flow Event

Abstract

Debris flows characterized by their rapid velocity and composition of water, mud, soil, and boulders, have the potential to inflict significant harm and present hazards to human life, infrastructure, and the natural surroundings. Numerical simulations provide a cost-effective approach for investigating different scenarios, hence boosting comprehension of flow dynamics and interactions. However, accurate modelling of these flows typically face difficult challenges arising from inherent modeling constraints and insufficient historical event data. The primary objective of the present study is to conduct numerical modeling and sensitivity analysis of the debris flow event that occurred in the Pitztal Valley, Austria in August of 2009, based on a multi-phase model for debris flows. The validation of the simulation results involves the comparison with the observed deposition patterns in the field. Various validation factors are employed to evaluate the accuracy of the simulated deposit and demonstrate a satisfactory level of precision in predicting deposition patterns. A sensitivity analysis is also conducted to examine the influence of in situ conditions on the effects of debris flow. The results demonstrate that numerical modelling can play an important role in engineering hazard assessment by analyzing the existing model’s effectiveness in simulating both historical and projected debris flow events.

Keywords

• geohazards
• debris flow
• debris deposition
• numerical modelling
• multi-phase