The term debris flow refers to the rapid downslope flow of poorly-sorted debris
mixed with water (Ballantyne, 2004). Debris flows are described by (Hungr et al.,
2014) as: “very rapid to extremely rapid surging flow of saturated debris in a steep
channel. Strong entrainment of material and water from the flow path”. They are a
widespread phenomenon in mountainous terrain and are distinct from other types
of landslides as they can occur periodically on established paths, usually gullies
and first- or second-order drainage channels. Debris flows in Great Britain are
most commonly found in upland Scotland but also in parts of Wales and the Lake
District
