Arid regions by definition receive little precipitation. Although the rocks and tectonic features underlying arid regions may not differ from other areas, the landscape is distinctive. With little vegetation and often loose surface material, erosion is the main factor in shaping the land surface.
Arid and Semi-arid Region Landforms
Erosional processes in arid and semi-arid regions include:
- mass wasting (surface creep, landslides, mud and debris flows, and rock topples and falls),
- water-driven or fluvial processes, and
- wind-driven or aeolian processes (dust, loess, sand dunes).
Surprisingly, water is an important agent of erosion in arid lands. Although streams may only be active during and right after a heavy rain, running water during a flash flood can carry tremendous amounts of material.
Arroyos or washes are dry stream beds that fill temporarily during rain storms. Flash floods are common following thunderstorms.