Personal Sample Essay - Basic Intro to River Transport

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Rivers transport their load according to sediment size through several processes.

For large river bedload, traction and saltation are involved to carry the load. Large rock fragments tend to roll or slide along the stream bed. Traction is usually most predominent near the source of a stream where river channel and valleyside gradients are steep, and steep valleyside gradients being capable of delivering coarse debris to stream channels. Smaller grains may then be transported by saltation, which is the lift from the streambed, which then falls back again within a short distance downstream.

For loads that are suspended, suspension is used as a transportation process. The greater the size of turbulence and velocity, the larger the quantity and size of particles that can be picked up. The material held in suspension usually forms the greatest part of the total load and the amount will increase towards the mouth of the river.

For dissolved load, solution is used to transport the load. The channel flow would contain acids, which attacks on readily soluble bedrock like calcium caronated, to be reduced into dissolved chalk.