What is the primary process by which the land surface is worn away?

The primary process by which the land surface is worn away is erosion. Erosion involves the removal of soil and rock from one location on the earth's surface and their transport to another site. This process can occur due to natural factors such as wind, water, ice, and gravity, as well as human activities that disturb the land. Erosion plays a critical role in shaping landscapes and affecting ecosystems.

While sedimentation refers to the process where materials that have been eroded are deposited in a new location, it does not describe the actual wearing away of the surface. Similarly, deposition is the accumulation of sediments, and transportation involves the movement of eroded materials. Erosion is the essential process resulting in the loss of land surface material, making it the correct choice in this context. Understanding these processes is crucial for managing land and water resources effectively, especially in stormwater and sedimentation control practices.