Snow avalanches threaten mountain communities worldwide. The first part of this session is dedicated to the movement and effect of flowing and powder snow avalanches. Emphasis is placed on flow dynamics, experimental techniques and practical application of numerical models to predict avalanche run-out distances, flow velocities, interaction with structures and impact pressures for hazard assessment and mitigation. The aim of the second part of this session is to present recent developments in the area of avalanche hazard/risk assessment and mitigation, with special attention paid to both methodological and legislative aspects, as well to the presentation of real world problem solutions and lessons learnt.