What is the term for the land that is formed by the action of water depositing sediment over time?

The term that specifically refers to land formed by the action of water depositing sediment over time is alluvium. Alluvium consists of clay, silt, sand, and gravel that are transported and then deposited by flowing water, typically in riverbeds, floodplains, and deltas. This process builds up new landforms and alters the landscape, making alluvium a crucial factor in sedimentary geology and land development.

Accretion, while closely related, refers more broadly to the gradual increase in land area due to the addition of new soil, sediment, or other materials, which may result from processes including but not limited to water deposition. Reliction involves the gradual drying up of water bodies that exposes new land, while erosion is the process of wearing away rocks and soil, typically resulting in the loss of land rather than the formation of new land. These definitions help clarify why alluvium is the most accurate term for land formed specifically by sediment deposition from water.