7.28 Numerical modeling of flows and falls

Abstract

A wide range of programs used to model mass movements currently exist. In this chapter, we provide an overview by presenting a selection of approaches used for modeling flows (e.g., debris flows and hyperconcentrated flows) and falls (e.g., rockfall). Mass-movement models support the study of geomorphic landscape changes, and, probably more importantly, they are commonly used for natural hazard assessments in mountain areas. As a first approach, the energy-line principle is widely applied, but not all flow and fall processes can be simulated with this rather simple method. Therefore, dynamic, process-based models have been developed, each one adapted to specific mass-movement problems. The energy-line principle is explained and models based thereon as well as modeling problems presented. Then, models and modeling approaches are introduced, which are used to describe mass flows with equations of motion and continuity. Rockfall is commonly modeled by trajectory models, which are explained theoretically and illustrated with an applied example. This state-of-the-art chapter on numerical modeling of flows and falls is followed by a discussion on future challenges in mass-movement modeling