Pieces of rock that are in contact with a stream bed can move without the assistance of a person thanks to the power of flowing water. This type of movement is known as bed load transport. When a river or stream flows through a channel that contains sediment, such as small rocks, boulders, sand, and silt, then the material carried by the water will move downstream. Bed load transport occurs when the particles move along, stuck to the bottom of the stream bed, and can include both rolling and sliding motions.

Factors that Affect Bed Load Transport

Several factors, such as the shape of the stream bed, the size of the particles, and the current velocity of the water, affect bed load transport. Streams with high velocities are more prone to bed load transport, as higher velocity provides more energy to move sediment particles. Additionally, larger particles require more energy to move, while smaller particles can require less. The shape of the stream bed also plays an important role in the amount of sediment it can move. For example, if the stream bed is a flattened or curved shape then the water’s flow can more easily move the sediment particles.

Measuring Bed Load Transport

The amount of sediment that is transported by a river or stream can be measured with a tool called the Bedload Assessment for Gravel-bed Streams (BAGS) Software. This tool uses the particle size distribution and velocity of the flow to measure the amount of sediment being transported. It also takes into account the shape of the stream bed, the water’s bed shear stress, and the effect of the sediment on the stream bed. The tool then computes the amount of bed load transport that occurs in a given time period.

Conclusion

Pieces of rock in contact with a stream bed can move without human assistance due to the power of flowing water and the factors that affect bed load transport. This process of sediment transport can be measured with the help of the BAGS Software, giving us valuable insight into the amount of sediment being transported by a river or stream.