River deltas are formed by a combination of processes including sediment deposition, erosion, and sediment transport. When a river flows into a body of water, its velocity decreases, causing it to deposit the sediment it carries. Over time, the accumulation of sediment forms a fan-shaped delta at the river mouth. Erosion from wave action and tides can also shape the delta, creating distributaries and channels that carry water and sediment to different parts of the delta. As the delta grows, it extends further into the body of water, creating new land and habitats for plants and animals.
