The speed and volume of a river are influenced by several key factors. Friction caused by obstacles and the roughness of the river channel can significantly slow down water flow, with smoother channels allowing for faster speeds.
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Volume of Water in a River
More than just a volume of water - Part 2
More than just a volume of water
Climate
In areas with distinct wet and dry seasons, the amount of water in the channel fluctuates according to the amount of rainfall received during each season. In other areas which are generally dry, the volume of water remains low throughout the year. Rivers found in hot and wet equatorial areas have a high volume of water in their channels.
The climate of the area a river flows can affect the volume of water in its channel.
Permeability of Rocks
High permeability increases infiltration and decreases surface runoff. Thus, volume of water in the river is low. Low permeability decreases infiltration and increases surface runoff. Thus, volume of water in a river is high.
Presence of Vegetation
Abudant vegetation decreases the amount of surface runoff, thus reducing the amount of water in a river. Sparse vegetation leads to high surface runoff, thus increasing the amount of water in a river.
Size of Drainage Basin
Bigger drainage area have greater amount of water in a river. It is because there is more surface area for rainfall to fall on, flows over the land as surface runoff or steeps into the ground before reaching the river. Smaller drainage area do not 'collect' as much rain water.
Speed of a River
Shallow River Water Speed Meter
Wetted Perimeter
Large wetted perimeter will cause a lot of friction, the speed of river will be low. Small wetted perimeter have less friction, the speed of the river will be high.
Shapes and sizes of a river channel affects the length and breadth of the channel in contact with the water.
Roughness of Channel
Obstacles (rocks,boulders,etc.) cause friction between the water and the channel, it will slow down river flow and speed.Therefore, smooth channel have higher speed than rough channel.
Gradient of Channel
Steep gradient, the river will flow quickly.Gentle gradient, the river will flow slowly
The speed of a river depends on the steepness (also known as gradient) of the channel.
Rivers flow downhill from a high attitude due to gravity.
