Which one of the following is likely to be the most prevalent form of weathering in hot-tropical desert areas?

In hot-tropical desert areas, mechanical (physical) weathering is the most prevalent form of rock disintegration. This dominance is primarily due to the extreme diurnal temperature ranges characteristic of arid climates [2]. During the day, intense solar radiation causes the outer layers of rocks to expand, while rapid cooling at night leads to contraction [2]. These repeated thermal stresses cause rocks to crack and split, a process often referred to as thermal expansion or insolation weathering [3]. While chemical weathering does occur when moisture is present, dry climates generally inhibit chemical processes and promote mechanical ones [3]. Additionally, salt weathering—a mechanical process where salt crystals expand in rock pores—is highly active in arid regions due to high evaporation rates [5]. Wind-blown sand also contributes to mechanical abrasion, further reducing rocks to sand in these water-scarce environments [4].

Sources

1. [1] Certificate Physical and Human Geography , GC Leong (Oxford University press 3rd ed.) > Chapter 7: Arid or Desert Landforms > The Mechanics of Arid Erosion > p. 69
2. [2] Certificate Physical and Human Geography , GC Leong (Oxford University press 3rd ed.) > Chapter 4: Weathering, Mass Movement and Groundwater > PHYSICAL OR MECHANICAL WEATHERING > p. 38
3. [3] Certificate Physical and Human Geography , GC Leong (Oxford University press 3rd ed.) > Chapter 4: Weathering, Mass Movement and Groundwater > CHEMICAL WEATHERING > p. 37
4. [5] Physical Geography by PMF IAS, Manjunath Thamminidi, PMF IAS (1st ed.) > Chapter 6: Geomorphic Movements > Salt Weathering > p. 85
5. [4] FUNDAMENTALS OF PHYSICAL GEOGRAPHY, Geography Class XI (NCERT 2025 ed.) > Chapter 6: Landforms and their Evolution > WINDS > p. 59