This session aims to discuss hydrology related to landslide occurrence both on local and regional scale. It focuses on the detailed analysis and modelling of hydrological processes on hillslope and catchment scale in order to improve our understanding and prediction of the spatio-temporal patterns of landslide triggering and slope deformation mechanisms.

Water circulation within a catchment and the resultant transient changes in both shallow and deep hydrological systems is the most common controlling and triggering factor of slope movements. However, incorporation of hydrological process knowledge in slope failure analysis, such as water-rock interaction, water storage, dynamic preferential flows or the influence of frost conditions to name a few, still lags behind. Also, the inclusion of regional hydrological information in rainfall thresholds analysis is underdeveloped. The research frontiers are connected with the complexity of real landslides such as the difficulty to monitor groundwater levels or soil moisture contents in unstable terrain and over large areas, the difficulty to understand the water pathways within heterogeneous regolith soils and fractured bedrock, which are the characteristic substratum where landslides occur, and the complexity of dynamically quantifying and predicting the hydrological exchange between a potentially unstable slope and its surroundings.

We invite research ranging from unsaturated zone, hillslope processes and regional hydrology which are applied to landslide research in a broad sense: ranging from soil slips to large scale deep-seated slope deformation. The session will give time to both laboratory and field monitoring studies, preferably quantitative, and based on novel measurement and modelling techniques. We invite pioneering research that includes hydrological information in local and regional hazard assessment. Moreover, we welcome studies that incorporate hydrological process knowledge in the geotechnical analysis and modelling setting the next step to improve landslide hazard analysis.