How do deserts form, and what processes contribute to desert landforms?

• A. Deserts form from high precipitation and lush vegetation.
• B. They form from persistent low precipitation and high evaporation; wind-sculpted features.
• C. They form due to volcanic activity alone.
• D. Deserts are formed by glaciation only.

Answer: (B)

Deserts form where water input is consistently far lower than what the environment loses to evaporation and drainage. That persistent moisture deficit, or aridity, is the defining condition. In such dry settings, wind becomes the dominant landscaper. It erodes rock, transports and deposits sand, and carves features like dunes and wind-sculpted surfaces such as yardangs and smooth desert pavements. Occasional rains do occur, but they’re not enough to sustain abundant vegetation or soil formation, so the arid conditions persist and the landscape remains desert-like.

High rainfall and lush vegetation would bring moisture and plant cover, not desert conditions. Volcanic activity can shape terrain but doesn’t by itself create a desert climate. Glaciation produces icy landscapes and different landforms, not the arid, wind-dominated environments that define deserts.