Which of the following is a dispositional feature of an arid region?

Analyze the question: The key word is "dispositional" (usually written depositional). It asks for a landform in a desert (arid) region that is formed by the deposition of material, not by erosion.

Explain the concept: In arid regions, wind does two main jobs:

• Erosion (deflation, abrasion) wears the land away and leaves erosional features.
• Deposition happens when the wind loses energy and drops the sand it was carrying, building depositional features.

Step-by-step review of the options:

• A. Barchan: A crescent-shaped sand dune formed when wind blows sand in one direction and deposits it. The horns point downwind. This is a depositional feature.
• B. Zeugen: Table-like ridges of resistant rock with softer rock beneath. Wind abrasion carves them, so they are erosional.
• C. Rock pedestal: A mushroom-shaped rock that is narrow at the base. Wind abrasion cuts the lower part more than the top, so it is erosional.
• D. Yardang: A streamlined ridge of rock lying parallel to the wind direction. Wind abrasion carves it, so it is erosional.

Only the barchan is built up by deposited sand.

Answer: A. Barchan

Tip: Remember that Barchans are Built up from sand (deposition). Zeugen, yardangs, and pedestals are all carved out of rock (erosion). In exams, ask yourself: "Was material removed or dropped?" Sand dunes (barchan, seif/longitudinal) mean deposition.