Climate and snow input at different spatial and temporal scales

Short- and long-term changes in precipitation or air temperature modulate the frequency and intensity of cascading alpine mass movements such as rock fall, debris flows, and snow avalanche events. Extreme precipitation or rain-on-snow events are two primary mechanisms by which these cascading processes can be triggered. Relatedly, the seasonal snow cover also influences rock slope stability through the timing and magnitude of snow melt. Early warning systems of mass movements thus depend heavily on the operational availability of high-resolution meteorological data. Additionally, analysis of past events requires accurate information on high-resolution precipitation patterns.Within the project cluster “Cascading Processes”, different research groups at the WSL/SLF will develop knowledge and models that can be used to anticipate future cascading events.  A particular focus is on a spatio-temporal characterization of the meteorological-climatological forcing and the contribution of precipitation, seasonal snow cover, and air temperature on triggering cascading processes.

Our project aims to collaborate with various proposed CAMM II projects within the clusters "Cascading processes' and "Early warning systems", providing meteorological, snow cover, ground temperature and snow melt data at different temporal and spatial scales. In particular, our data will help to understand the influence of timing and magnitude of spatio-temporal dynamics of snow melt and intense precipitation on rock slope instabilities, rock avalanches, and debris flows originating from rock avalanches. We will run different downscaling methods to provide various climates required by projects studying cascading processing in a changing climate at different temporal and spatial scales: Point and grid data will be provided at the (1) event , (2) seasonal and (3) climate scale using different types of models depending on required model complexity and the need for non-linearity. Information on snow, snow melt and surface water input will be provided by Alpine3D and HICAR-FSM or WRF-CRYOS. Our data will in particular help to understand the  link between spatio-temporal dyanmics of precipitation/snow melt and rock slope instabilities potentially triggering a cascade of alpine processes.

The individual objectives of this project task are the following:

1. Which meteorological parameters are most important for triggering cascading processes in a changing climate in high-alpine terrain?
2. How do spatio-temporal dynamics of snow melt and extreme precipitation events affect rock slope destabilisation in the presence of permafrost?