As they transport sand, ocean waves and currents shape a variety of coastal landforms. ... Waves and currents move and build up sand deposits to form a sandbar under the water surface. As more sand is deposited, the sandbar rises above the surface to become a barrier island.
Waves shape the coast through erosion by breaking down rock and transporting sand and other sediment. When large waves hit the shore, their energy can break apart rocks. Waves also erode by abrasion. When a sediment-carrying wave hits land, the sediment wears away rock like sandpaper wearing away wood.
The significance of the yearly flooding of the Nile Valley is important because it replenishes nutrients in the soil and makes the land more fertile for plants to grow.
