Final answer:
Gravity is the primary factor used to classify different types of mass movement, such as landslides, mudflows, and slump. Wind and water can contribute to the process, but gravity's constant force makes it the main factor in classification.
Step-by-step explanation:
Classifying Types of Mass Movement
When classifying different types of mass movement, it is primarily gravity that is considered. Mass movements are a type of erosion and downhill movement of soil and rock that occur under the influence of gravity. The term landslide includes various ground movements such as rock falls, deep failures of slopes, and shallow debris flows. While gravity is the main factor, other factors like water saturation, geological instability, and human activities can contribute to slope instability leading to mass movements. Contrary to wind and water force, gravity acts constantly on the mass, causing it to move downslope when the forces resisting movement are exceeded.
Despite wind and water being significant erosion agents, they are not primary factors in classifying types of mass movement. It is essential to understand that while these elements can contribute to the process by weakening the material on slopes or adding weight due to water saturation, the classification of mass movements is based on how gravity causes the material to move. Examples of mass movements, aside from landslides, include mudflows, slump, and creep.