Which factor is NOT a trigger of mass movement?

Wind erosion is not considered a trigger of mass movement because it primarily acts on the surface soil and rock, wearing them away but generally not causing large-scale movements of mass like landslides, mudslides, or other types of mass wasting. Instead, wind erosion tends to shape and remove the surface material without displacing significant volumes of earth in a manner that results in mass movement.

In contrast, deforestation can destabilize slopes by removing roots that anchor the soil, making the ground more susceptible to sliding. Excess precipitation adds weight to slopes and saturates soils, both of which can induce mass movements when the material becomes unstable. Earthquakes generate seismic waves that can disturb and dislocate ground material, easily leading to landslides or other forms of mass movement. Each of these factors contributes directly to conditions that promote mass movement, unlike wind erosion, which primarily affects surface characteristics without resulting in mass mobilization.