What Is a Draw in Geography?
A draw is a natural terrain feature, resembling a small valley, typically found in hilly or mountainous landscapes. It forms as a channel or indentation on a hillside, often between two parallel ridges or spurs. Draws are usually dry, serving as a pathway for water only during periods of rainfall, and are common in arid and semi-arid environments where water flow is intermittent.
Defining Features of a Draw
Draws are smaller than larger valleys, characterized by their distinct shape. On topographical maps, draws appear as U-shaped or V-shaped contour lines, with the closed end pointing uphill. The terrain within a draw generally slopes downward in one direction, creating a sharp incline with a notable vertical drop over a short horizontal distance.
The streambed of a draw is typically dry for most of the year. However, it can contain an ephemeral stream. During heavy rains or snowmelt, these channels can temporarily fill with water. Draws vary in size, from small, shallow channels to more pronounced, steep-sided depressions. Vegetation within draws often consists of species adapted to dry conditions, with denser growth occurring where moisture collects.
How Draws Form
Draws are primarily shaped by the erosive power of water flowing over the landscape, particularly in environments with unconsolidated soil or easily erodible rock. Intermittent water flow, characteristic of arid and semi-arid regions, plays a significant role in their creation. When rainfall occurs, water collects and flows down hillsides, carving out these channels.
Flash floods are common in these landscapes and contribute to the deepening and widening of draws. The intense water flow scours the terrain, transporting sediment and shaping the depression. Draws are often etched into hillsides or along the flanks of ridges. A draw typically runs perpendicular to a ridgeline, ascending with the surrounding terrain until it disappears upslope. Over long geological periods, a draw can represent an early stage in the development of a larger valley.
Draws Compared to Other Landforms
Draws are often differentiated from other similar geographical features, which can sometimes be confused due to overlapping characteristics or regional terminology. A gully, for instance, is a landform carved by running water, often appearing as a deep ditch. While “draw” and “gully” are sometimes used interchangeably, a gully is generally considered smaller, sometimes described as hardly larger than a ditch.
A wash is another term used in arid regions, referring to a dry creek bed that carries water only after rainfall. Washes and draws are typically dry and flow intermittently. The term “arroyo” is also common, particularly in the Southwestern United States, describing a dry streambed or gulch that fills temporarily with water after significant rain. Draws are sometimes referred to as arroyos, though arroyos can be steep-sided with nearly vertical banks.
Ravines are deeper and narrower valleys or gorges formed by water erosion. Draws are generally shallower than ravines, though in some regions, a draw might be locally called a ravine. Ravines tend to be larger than gullies.
Canyons represent a much larger scale of water-carved landforms, characterized by significant depth and steep cliffs. Draws are considerably less wide and deep than canyons. The distinct relationship of a draw, trending perpendicular to a ridgeline, also helps distinguish it from other linear depressions like valleys, which run parallel to ridges.