The top soil would most likely be thicker in lush tropical area.
Step-by-step explanation:
The top soil presents just above the earth's surface in the upper position of soil profile. It's thickness is 2 to 3 inches. Tropical area receives highest rainfall and direct sunlight which promotes the growth of lush vegetation that tightly holds the soil.
Dry region is devoid of vegetation. And it is free zone for air passing. With high speed wind top soil blow out from the upper surface and make surface bare. The thickness of soil in tropical area is maximum and pure.