Fundamentals of Surveying Practice Exam 2026 – Complete Test Prep

The formation of land from the slow buildup of alluvium is known as accretion. This process involves the gradual addition of soil or sediment to land, typically occurring along riverbanks or shorelines due to the deposition of sediment carried by water. Over time, as alluvium accumulates, it can lead to the expansion of land areas.

In contrast, erosion refers to the process of wearing away and removing soil and rock from the Earth’s surface. Alluvium itself is the sediment that is deposited by flowing water, while avulsion refers to the sudden change in the course of a river, which can result in the rapid separation of land from one bank to another. Therefore, accretion is specifically the term that relates to the slow buildup of sediment, distinguishing it from the other processes that deal with land loss or sudden changes in landform.