The velocity of a river is the speed that water travels down the river channel. The gradient or slope of the stream bed, the texture of the stream bed, and the width of the stream bed affect the river's velocity.
Velocity in a river is higher when the stream bed is steep, narrow and smooth. Velocity is lower if the stream bed is flat, rough and wide. Since water is a valuable resource, scientists use the velocity of a river to help determine how much water is flowing through a river channel. When the area of the water is multiplied by velocity, the result is a reliable prediction of the discharge of water. The standard measurement unit for the discharge of flowing water is expressed as cubic feet per second.