2. Load The word load is used to describe the rock particles that are carried by a river. There are three categories: Bedload â large particles carried only at times when the river has much energy. Suspended load â small particles that can be carried by the water, making it look muddy. Dissolved load â minerals carried by solution that are not visible.
3. A river obtains its load from two main sources: About 90% comes from the movement of material down the slopes of the river valley by weathering and mass movement. 10% comes from the erosion of the bed and banks of the river channel.
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5. River capacity â the total amount of load that a river can carry at any one time. Capacity increases as discharge increases. River competence â the maximum size or weight of material a river can transport. In times of flood, a riverâs competence will increase â it will be able to carry bigger particles. Capacity and competence increase downstream, as discharge increases, and during times of flood.
6. Processes of River Transportation Traction â large boulders are rolled along the river bed. Saltation â pebbles, sand and gravel bounce along the river bed. Suspension â fine particles are carried by the water, making the river look muddy. Solution â minerals that are dissolved in the water, and therefore not visible.
8. The Hjulstrom curve is a graph that shows the relationship between the velocity of a river and the particle sizes that may be transported. It shows the velocity needed to pick up material of a certain size (velocity needed for erosion to take place), and the settling velocity when deposition will occur.