This is the 2nd edition of one of the most comprehensive accounts of debris flow, describing both theoretical and applied aspects. In the first part, the fundamental mechanical characteristics are discussed, including flow characteristics, type classification, mechanics, occurrence and development, fully developed flow, and deposition processes. The second part sheds light on the application of the theories presented in computer-simulated reproductions of real disasters. Special attention is paid to debris flow controlling structures, design effectiveness and performance, soft countermeasure problems, such as the identification of debris flow prone ravines and the prediction of occurrence by means of precipitation threshold. This new edition has been wholly revised and updated, and now includes a new chapter on sediment runoff models that include debris flow processes and new sections concerning landslides. The qualitative and fundamental character of this text makes it an excellent textbook for graduate-level courses and it is recommended reading for professionals in engineering, geosciences and water resources who are working on the mechanics and countermeasures of debris flow. The original, Japanese version of this book was awarded the 'Publishing Culture Prize' by the Japanese Society of Civil Engineers (2004). Tamotsu Takahashi is Professor Emeritus at the University of Kyoto. In addition to his academic positions, he is the Director of the Association for Disaster Prevention Research in Kyoto. Professor Takahashi began his career in flood dynamics research, and increasingly focused on debris flow and flood hazards. He has been honoured with several awards from the Japan Society of Civil Engineers and the Japan Society of Erosion Control Engineering. An earlier book entitled 'Debris Flow', by Tamotsu Takahashi, in the book series of the International Association of Hydraulic Engineering and Research, was published by Balkema Publishers, now a part of the Taylor & Francis Group.