Chapter 32 - Transportation by Streams

Streams transports its load of sediment in four ways: traction, saltation, suspension, and solution. Traction is the sliding or rolling of heavier particles along the stream bed. Through hydraulic action large pieces of rock are literally rolled or dragged along the stream bed. These large pieces of rock are broken down into smaller ones through abrasion, the resulting smaller particles are of gravel and sand sized fragments. Saltation is the movement of the resulting fragments from the process of traction. The fragments are carried through the riverbed by the speed of the water, which lifts the fragments, causing them to bounce through the river. Suspension is the process by which very fine sediment, silt and clay sized grades is moved through the river, suspended in the river. Material in suspension does not touch the bottom of the river, except when the water is slowed to a standstill. Solution is the movement of dissolved rock material as a liquid solution in the river.