Which of the following is NOT a type of erosion?

Coastal erosion refers to the process of coastal land being eroded by the action of waves, currents, tides, and other forces of nature, which shape and reshape shorelines. In contrast to the other forms of erosion listed, which occur primarily on land as a result of water runoff, splash erosion, rill erosion, and gully erosion are all internal processes that happen inland due to the movement of water over soil surfaces.

Splash erosion describes the detachment and displacement of soil particles that occurs when raindrops hit the surface of the soil. Rill erosion occurs when small channels form on the surface of the soil due to concentrated water flow, leading to further soil removal. Gully erosion is a more advanced form of rill erosion where larger channels are formed, resulting in significant erosion and sediment transport.

Recognizing that coastal erosion is distinctly related to maritime environments makes it clear that it does not belong to the same category as the other types of erosion mentioned, all of which occur due to terrestrial water movement. This understanding highlights the unique nature of coastal erosion relative to the other forms listed.