Debris and hyper-concentrated flows are among the most frequent and destructive of all water related processes. They mainly affect mountainous areas in a wide range of morpho-climatic environments and in recent years have attracted more attention from the scientific communities. There is also public concern, due to the increasing frequency with which they occur and the death toll they claim. Because of greater population pressure on natural resources in hazard-prone areas and expanding activities that can increase the magnitude of hazards, planners need to improve the criteria used to identify debris flow risk areas and to design suitable prevention and mitigation measures.The Second International Conference on Debris Flow, papers from which this book is comprised, provided a forum for engineers, scientists and managers from laboratories, industries, governments and academia to exchange knowledge and expertise in the fields of erosion and slope instability, sediment transport, debris flow and debris flood data acquisition, debris flow phenomenology and laboratory tests, using the most advanced, state-of-the-art methodologies in monitoring, modelling, mechanics, hazard prediction and risk assessment. Papers have been grouped into the following subject areas: debris flow modelling; debris flow phenomenology; debris flow mobilization; debris flow disaster mitigation; case studies; debris flow rheology and laboratory tests; debris flow and landslide phenomena; debris and hyper-concentrated flows; structures and their effects on debris flow; problems and mechanics of solid-liquid flows; and shape failure and landslides.