A mudflow or mud flow is a form of mass wasting involving “very rapid to extremely rapid surging flow” of debris that has become partially or fully liquified by the addition significant amounts of water to the source material. Mudflows contain clay, which makes them more fluid than debris flows; thus, they are able travel farther and across lower slope angles. Mudflows often start as slides, becoming entrained along path; such events often called. Landslide more general term than mudflow. It refers gravity-driven failure subsequent movement downslope any types surface movement soil rock. Term incorporates earth slides, rock falls, mudslides, amongst other categories hillslope mass movements. Sudden thaw. They consist mainly plus fragments behave like floods. Material from construction excavation.