The river picks up sediment and carries it downstream in different ways.
There are four types of transportation:
- Traction - large, heavy pebbles are rolled along the river bed. This is most common near the source of a river, as here the load is larger.
- Saltation - pebbles are bounced along the river bed, most commonly near the source.
- Suspension - lighter sediment is suspended (carried) within the water, most commonly near the mouth of the river.
- Solution - the transport of dissolved chemicals. This varies along the river depending on the presence of soluble rocks.