The predominant process of weathering in the desert region is

1. Analyze the question The question asks which type of weathering dominates in desert regions. Think about the climate: deserts are very hot by day, cold at night, and have very little water and sparse vegetation.

2. Explain the concept Weathering is the breakdown of rocks in place (without transport). The main types are:

• Physical (mechanical) weathering: rocks break apart without changing their chemical composition. Examples are thermal expansion and contraction, frost action, and salt crystallization.
• Chemical weathering: rocks decompose through reactions with water, oxygen, and acids. It needs plenty of moisture.
• Biological weathering: caused by plants and animals (root growth, burrowing). It needs vegetation and life.
• Solution: a form of chemical weathering where minerals dissolve in water (e.g. limestone). It also needs water.

3. Step-by-step solution

• Deserts have a very large diurnal temperature range: scorching hot in the day (above 40°C) and cold at night.
• Rocks expand when heated and contract when cooled. Repeated expansion and contraction creates stress, causing cracks, exfoliation (peeling off of layers), and granular disintegration.
• Water is scarce, so chemical weathering and solution are minimal.
• Vegetation is sparse, so biological weathering is minimal too.

Therefore, the dominant process is physical weathering (specifically insolation weathering, also called thermal fracture).

4. Answer The correct option is C. physical.

5. Exam tip Remember: "Hot and dry = physical; warm and wet = chemical." Deserts are dry, so think physical weathering (temperature changes). Humid tropical areas like the Niger Delta rainforest are dominated by chemical weathering.