What is a primary factor influencing the capacity of a river to transport sediment?

The capacity of a river to transport sediment is primarily influenced by water velocity. As the velocity of the water increases, its ability to pick up and carry sediment from the riverbed and surrounding areas also increases. Fast-moving water has more kinetic energy, which allows it to lift larger particles and transport them over greater distances.

In contrast, slower water velocity may not have the energy required to move larger sediments, leading to sediment deposition instead of transport. This understanding is crucial in river dynamics as it also helps explain how rivers shape landscapes over time.

While water temperature, water chemistry, and bedrock type can affect sediment transport in indirect ways, such as altering water density or influencing erosion rates, they do not have as straightforward and direct an impact on the overall capacity to move sediment as water velocity does.