Rivers Flashcards
Parts of a river - drainage basin
Area of land drained by a river
Source
Beginning or start of a river
Confluence
Point at which two rivers or streams join.
Tributary
A stream or smaller river which joins a larger stream or river.
Watershed
Edge of highland surrounding a drainage basin marking the boundary between two drainage basins.
Mouth
Where the river comes to an end usually entering the sea.
River processes
How the river shapes the land in different ways eg erosion, transportation and deposition.
Erosion
Breaking down of rock and soil
Hydraulic action: force of the river
Abrasion: carrying stones and other materials grinds the bedload
Attrition: rocks being carried smash together and break into smaller particles.
Solution: soluble particles are dissolved in the water
Transportation
Solution: minerals dissolved in the water and carried along.
Suspension: fine light material is carried by the river
Traction: large boulders and rocks rolled along the river bed.
Saltation: small stones and pebbles carried along the river bed.
Deposition
When a river loses energy, it will drop or deposit some of the material it is carrying.
May take place when a river enters an area of shallow water or towards the mouth of a river.
Long profile
This is how a river changes shape as it flows from the source to its mouth
Upper course of river
Often in an upland area.
Flows over uneven surfaces and steep slopes.
Vertical erosion
Lower course of a river
The slopes become less steep.
Depth and width will increase.
The discharge ( amount of water flowing) will increase as the river approaches the sea.
How do waterfalls form? Waterfalls
When a river runs over alternating layers of hard and soft rock, waterfalls may form.
Middle course of river - meanders
River has more energy and a high volume of water.
River erodes laterally ( side to side) forms large bends and then horseshoe loops called meanders.
Formation of meanders due to erosion and deposition.
