These three factors are gradient, discharge and channel characteristics.
1. Gradient is the steepness or vertical drop over a specific distance. Water flows more rapidly down a steep slope than a gradual one. A tumbling mountain may drop 40 or more meters per kilometer.
2. Discharge is the volume of water flowing down a stream over a given period of time and is usually expressed as cubic meters per second. When discharge increases then velocity of the water also increases as seen during a flood.
3. Channel characteristics include the shape and roughness of a stream channel. Friction between flowing water and the sides of the channel, the banks, makes the water- flow near the banks be much slower than near the center of a stream.
