A ravine is a very small valley, which is often the prouct of streamcutting erosion. Often found in urban areas, ravines are typically classified as larger in scale than gullies, although smaller than valleys. A ravine is generally a slope landform of relatively steep (cross-sectional) sides, on the order of twenty to seventy percent in gradient. Ravines may or may not have active streams flowing along the downslope channel which originally formed them; moreover, often they are characterised by intermittent streams, since their geographic scale may not be sufficiently large to support a perennial watercourse.