Which of the following is not a process of wind erosion?

Hydraulic action is not a process of wind erosion. Wind erosion is a process whereby the wind picks up and carries away loose materials such as sand, silt, and clay from the Earth's surface. The four main processes of wind erosion are abrasion, attrition, deflation, and saltation. Abrasion occurs when the wind carries particles that scrape and scour the Earth's surface, while attrition is the wearing down of particles as they collide with each other or other materials. Deflation occurs when the wind removes loose particles from the Earth's surface, leaving behind a depression or hollow. Saltation is the movement of particles by the wind in a hopping or bouncing motion. Hydraulic action, on the other hand, is a process of water erosion, whereby the force of water breaks down and wears away rocks and other materials. Therefore, hydraulic action is not a process of wind erosion.