This book on debris flow discusses fundamental mechanical characteristics, including flow characteristics, type classification, mechanics, occurrence and development, fully developed flow, and deposition processes. It presents applications of the theories in computer-simulations of real disasters. This second edition covers debris flow controlling structures, design effectiveness and performance and soft countermeasure problems, and includes a new chapter on sediment runoff models. An excellent textbook for graduate-level courses, it is also recommended for professionals working on the mechanics and countermeasures of debris flow.