Wind erosion is common in arid areas because______?

Analyze the question: It asks why wind erosion (deflation, abrasion, attrition) is common in arid (desert) areas.

Concept: Wind can only pick up and carry loose particles if two main conditions are met:

1. The wind must be strong enough.
2. The surface must be loose, dry and exposed, with little to slow or block the wind.

Arid areas have both. They have sparse or no vegetation, so there are few natural wind breaks such as trees and grass. Their soil is dry, loose and poorly bound together. Strong winds blow across the open surface unchecked.

Checking each option:

• A. Rains are widespread and long lasting. Wrong. Arid areas are defined by scarce rainfall. Heavy rain would bind soil and encourage vegetation, which reduces wind erosion.
• B. Wind speed is high and there are few wind breaks. Correct. Open, barren land lets the wind blow fast and pick up loose sand and dust, which then abrade rock surfaces.
• C. Pressure falls below normal in desert areas. Wrong. Many deserts, such as the Sahara, lie under subtropical high-pressure belts. Even if pressure varied, it does not directly explain erosion.
• D. The rocks are resistant to heat. Wrong. Desert rocks are actually broken down by heat (thermal expansion and contraction), which produces the loose debris the wind then moves.

Exam tip: For "why is X common in arid areas" questions, think of the keywords dry, sparse vegetation, loose soil, strong winds. Eliminate any option that mentions heavy rain or abundant vegetation.