Sediment induced disasters have been studied in a wide variety of research fields ranging from social to natural science, with many interesting results. This special issue provides engineers and scientists with an opportunity to share knowledge and experience in engineering research concerning mass sediment movement and related disasters. To clarify this issue’s objectives and encourage submissions, topics have been discussed based on the needs, activities, and possible contributors classified into four categories: 1) Results based on field and literature surveys and data analysis for catastrophic, recent and historical mass movement, and corresponding disaster events. 2) Results based on field surveys and data analysis for recent usual mass movement events and corresponding disasters resulting from rainfall, earthquakes, volcanic activity, and glacier lakes and natural landslide dam events. 3) Mechanics and numerical modeling for mass movement. 4) Measures against sediment-induced and similar disasters. Last August, we began inviting submissions on these themes just as Typhoon Morakot slowly crossed Taiwan, causing historically significant rainfall events in southern Taiwan involving numerous landslides and debris flows and precipitated casualties, landscape changes, channel bed variations, etc., similar to the catastrophic sediment events occurring in Venezuela in 1999. Two papers describe what happened in Taiwan and Venezuela, providing advice on possible measures against such abnormal catastrophes. Three contributions describe historical catastrophes involving mountain collapse based on analysis of the literature, topography and field surveys, and numerical models. A total of 11 papers have been submitted, 4 of which concern applicability of constitutive equations for debris flow, numerical models for landslide occurrence due to rain fall and flood processes due to rapid landslide dam erosion, and sediment issues resulting from glacier lake outburst flooding. Two submissions focus on corrective measures. All papers have been reviewed, revised, and accepted for publications, and we believe this special issue will stimulate future studies and prove useful in practical and scientific fields. We heartily thank all of the authors undergoing the review process, and express our sincere appreciation to the distinguished reviewers, without whose invaluable aid this issue would not have been possible.