Hydrogeomorphic process chains in high-mountain areas: a modelling perspective

Complex cascading processes such as glacial lake outburst floods (GLOFs), or rock slides or rock-ice avalanches evolving into long-runout debris flows or related phenomena, are fairly common phenomena in glacierized high-mountain areas. Massive events resulting in severe losses have triggered scientific and public attention in the early 2020s, such as the Chamoli process chain in 2021 and the South Lhonak process chain in 2023. Managing the related risks is a complex and challenging task. Social scientists emphasize the need for better strategies of policy implementation and increasing awareness and preparedness, whereas researchers with a background in natural and technical sciences often believe in the importance of computer models to predict or to better understand process chains.

This contribution summarizes the current efforts, trends, and challenges in the simulation of cascading hydrogeomorphic processes in high-mountain areas. The past decade has seen major progress in model development and application, with emerging tools allowing to move from model chains to integrated multi-phase approaches. At the same time, major challenges in terms of process understanding and uncertainties of data and parameters have been identified. “Successful” back-calculation of events is often based on case-specific parameter optimization, whereas predictive modelling efforts, despite some progress, face a number of conceptual and practical challenges. A still emerging field consists in the use of model results for science communication and awareness- and preparedness-raising – employing, for example, virtual reality, augmented reality, and computer gaming. Such efforts may help bridging the gap to the societal components of risk management.