Floodplains are areas of land near rivers, lakes, and other bodies of water that are prone to flooding during heavy rains or when water levels rise. Synonyms for floodplains include wetlands, marshes, swamps, delta, estuary, floodplain wetland, alluvial plain, riverine plain, riparian zone, and flood-field. Wetlands are areas of land that are saturated with water, while marshes are wetlands with grassy vegetation. Swamps are wetlands with trees and shrubs. Deltas are flat areas of land formed by sediment deposition at the mouth of a river. Estuaries are bodies of water with a mixture of fresh and saltwater. Floodplain wetlands are wetlands that are regularly flooded. Alluvial plains and riverine plains are flat areas of land along rivers. Riparian zones are areas adjacent to bodies of water.