Rivers Flashcards
Upper course:
Steepest part of the river, start of the river.
Middle course:
River starts to flow, transports lots of sediment, river gets wider and more tributaries join together.
Lower course:
Valley sides disappear, the river approaches its mouth, deposition is now a dominant process.
Define attrition:
Rocks smashing together and becoming smaller.
Define solution:
Soluble particles and minerals are dissolved into the river.
Define abrasion:
Rocks carried along the river wear down the river bed and banks.
Define Hydraulic action:
the force of the river against the banks cause air to be trapped in cracks, the pressure builds and they are slowly worn away.
Define low discharge:
Low energy
Define interlocking spurs:
Hard resistant rocks that are formed when areas of harder rock cannot cut through them.
What is a meander?
The water flows in sharp bends.
What is a ox-bow lake?
A horseshoe of a semi-circular area that represents the former course of a meander that has been cut off by erosion of the meanders neck and the river continues to flow over the straighter path, leaving the lake isolated
What is a levees?
Small natural hills created by deposition of larger sediment first which then builds up hills and less heavy sediment is dropped over it.
What is a estuary?
Part of the river that meets the sea.
Define soft-engineering?
Adapting to live with a river, such as adding banks, this costs less money and saves time, to try and reduce things like erosion to coastlines etc
Define hard engineering?
Changing a rivers course, costs a lot of money and is bad for the environment and surroundings.
What is a drainage basin?
All flowing surface water converges to a single point ie: a lake or ocean
What is deposition?
The laying down of sediment carried by flowing water, which looses energy and can no longer carry the sediment so drops it.
Formation of a v shaped valley?
Rocks which have fallen into a river assist the process of erosion, this leads to more erosion and the channel becomes deeper and wider
What are interlocking spurs?
Land jutting out causing a river to meander
