Mass wasting is what happens when soil or sand or rocks slide off the side of a mountain or slope of some sort. Basically like a landslide. It usually happens around water and then affects the quality of water and causes mudflows.
which soil, sand, regolith, and rock move downslope typically as a solid, continuous or discontinuous mass, largely under the force of gravity, but frequently with characteristics of a flow as in debris flows and mudflows.