Question
Give reasons why some rivers have big deltas in their mouths.
Answer
Some rivers have big deltas in their mouths because of the following reasons:
- The river carries a large amount of sediment, such as sand, silt, and clay, which is deposited at the mouth of the river when it meets the sea or a lake.
- The river flows into a body of water with slow currents or no currents, such as a lake or an estuary. The sediments carried by the river settle down in such areas and cause the delta to form.
- The river may have a high gradient or slope, which means it flows quickly and erodes the surrounding land more effectively, carrying a larger load of sediment to deposit at its mouth.
