What factors influence stream velocity?

Stream velocity is primarily influenced by the gradient, or slope, of the streambed, and the volume of water flowing within the stream. A steeper gradient generally results in faster-moving water because gravity exerts a stronger pull on the water, leading to increased kinetic energy and velocity. Similarly, a greater volume of water, when compared to a smaller volume at the same gradient, can also increase the velocity due to the greater overall energy present in the flowing water.

Other factors such as the width and depth of the stream, temperature, salinity, and climatic conditions like rainfall and evaporation rates can also impact stream flow, but they do not directly influence velocity in the same fundamental way as gradient and volume. For instance, while width and depth can affect flow characteristics, the primary drivers of velocity remain the quantity of water and the incline of the streambed.