A gully is a landform created by running water, mass movement, or commonly a combination of both eroding sharply into soil or other relatively erodible material, typically on a hillside or in river floodplains or terraces. Gullies resemble large ditches or small valleys, but are metres to tens of metres in depth and width, are characterized by a distinct 'headscarp' or 'headwall' and progress by headward erosion. Gullies are commonly related to intermittent or ephemeral water flow, usually associated with localised intense or protracted rainfall events or snowmelt. Gullies can be formed and accelerated by cultivation practices on hillslopes in farmland, and they can develop rapidly in rangelands from existing natural erosion forms subject to vegetative cover removal and livestock activity.