A river is a natural waterway that transports water through a landscape from higher to lower elevations. A river is a component of the water cycle. The water within a river is generally collected from precipitation through surface runoff, groundwater.
- Source --> The start of a river
- Confluence --> Where two rivers meet
- Tributary --> One river that flows into another
- Drainage basin --> Catchment area which drains into one river system
- Mouth --> where a river ends (usually a sea or an ocean)
Rivers, just like coasts erode, transport and deposit.
See main article River processes
See main article River landforms
The sections of a river's journeyEdit
There are three main sections of a river's course from source to sea:
This has the most GPE and virutally no KE. What is more, the Wetted Perimeter is fairly large because there are lots of rocks in the river at this point. There is lateral erosion as the water is attempting to reach its base level (sea level), thus forming a v-shaped valley floor. The water transports material; large angular boulders downstream.
the middle course of a river
In the lower course, the river has a high volume and a large discharge. The river channel is now deep and wide and the landscape around it is flat. However, as a river reaches the end of its journey, energy levels are low and deposition takes place. The river now has a wide floodplain. A floodplain is the area around a river that is covered in times of flood. A floodplain is a very fertile area due to the rich alluvium deposited by floodwaters. This makes floodplains a good place for agriculture. A build up of alluvium on the banks of a river can create levees which raise the river bank. Deltas are found at the mouth of large rivers - for example, the Mississippi. A delta is formed when the river deposits its material faster than the sea can remove it. There are three main types of delta, named after the shape they create: arcuate - the land around the river mouth arches out into the sea, the river splits many times on the way to the sea, creating a fan effect. cuspate - the land around the mouth of the river juts out arrow-like into the sea. bird's foot - the river splits on the way to the sea, each part of the river juts out into the sea, rather like a bird's foot.
Land use along a riverEdit
See main article River flooding eacht ln