Energy of the River

The energy of the river is determined by 2 factors- speed of flow and volume of water. Therefore, when the speed of flow and the volume of water is high, the energy of the river is also high. We say that there is a positive relationship between energy of river and the speed of flow and the volume of water that the river is carrying.

There are 3 factors affecting the speed of the river. (GRoW)
1) Gradient of channel
Rivers flow downhill from a height due to gravity. Therefore, a steep gradient will cause the speed of the river to be fast.

2) Roughness of channel
A smooth channel without obstacles like rocks and boulders will increase the speed of the river.

3) Wetted perimeter
The lesser the water that contact the river channel, the higher the speed of flow due to less friction.

There are 4 factors affecting the volume of water in the river. (SPCPetrol)
1) Size of Drainage Basin
The larger the drainage basin, the higher the volume of water of the river.

2) Presence of Vegetation
More vegetation will result in higher interception and lower runoff, resulting in lower volume of water. Vegetation will also delay the amount of water that reaches the river in a short time, preventing floods.

3) Climate
If the rainfall is high, the river will have a higher volume of water.
Climate will also determine the amount of vegetation in the river vicinity.

4) Permeability of Rocks
High premeability will result in low volume of water due to decrease in runoff.