This session invites presentations on recent developments and state-of-the-art in understanding, measuring/monitoring, and modelling hydrogeological processes in mountainous catchments at regional and local scale. The contributions may range from fundamental, theoretical investigations to applied case studies in all types of mountainous aquifer systems. Potential topics include groundwater in the hydrological cycle (e.g., recharge, runoff dynamics, stream-aquiferinteraction), groundwater quality, exploration techniques (e.g., hydrogeophysics, isotope methods, modelling), and applied hydrogeological studies.