Geography Rivers Flashcards
Middle Course land uses
Settlement, farming, tourism, angling, transport
Upper course land uses
Tourism, farming, forestry, reservoirs, sports and HEP
Lower course land uses
Settlement, farming, transport, industry
Formation of a V-shaped valley (4 steps)
Vertical erosion, freeze/thaw, gravity, river transport
Formation of a waterfall
Softer rock is worn away by falling water and rock particles and a plunge pool is formed, hard rock above is undercut as erosion of soft rock continues, hard rock collapses into the plunge pool to be broken up and carried down the river, the position of the falls move back leaving a gorge behind
Abrasion
Sand and stones in the river scrape against the bed and banks
Attrition
Rocks and stones knock together and wear each other away
Solution
Water dissolves soluble minerals from the beds and banks helping to break them up
Hydraulic action
In fast-flowing rivers water is forced into cracks in the bank, breaking it up over time
Formation of a levee
In its lower course a river may flood over its flood plain and when the flood recedes silt and mud are left behind making a fertile soil called alluvium, the flood water deposits the larger particles of alluvium first forming natural embankments called levees
Formation of a meaner
River is faster in the outside bend and begins to erode the bank outwards, on the slower inside bend the river deposits material making a shallower area of sediment called a slip-off slope.
Formation of an ox-bow lake
As the river meanders erosion takes place on the outside bend meaning the neck begins to narrow within the meander, during a flood the river cuts through the neck and afterwards the river will take the new, shorter route, as deposition occurs on the banks the meander is cut off to form an ox-now lake
