Action of Winds - SS1 Geography Past Questions and Answers - page 2

The primary processes of wind erosion are abrasion, which involves particles colliding with surfaces and causing physical weathering; attrition, where particles collide with each other, becoming smoother and rounded; and deflation, which removes fine-grained materials, causing depressions in the landscape.

Barchan dunes are crescent-shaped with a gentle slope on the windward side and a steeper leeward slope. They form in sandy deserts, migrating with the prevailing wind, and are typically composed of sand.

Parabolic dunes differ from other dunes by having a U-shaped, open end pointing into the wind. They often form in coastal areas and are characterized by their unique shape, which is created by the presence of vegetation anchoring the dune tips.

Nebkhas are small sand dunes that form around vegetation in arid regions. They play a crucial role in stabilizing desert soils by trapping wind-blown sand, preventing further wind erosion.

Loess deposits are known for their fertility and are essential for agriculture. They are often found in areas with rolling hills and bluffs, providing rich soil for farming.

Blowouts are depressions or hollows in the landscape resulting from deflation, a process where the wind removes fine-grained materials like sand, silt, and clay. These depressions can become deeper and more extensive as the wind continues to remove material, often causing damage to the local ecosystem.