4 - River Processes and Pressures Flashcards
What is traction?
Large particles like boulders are pushed along the river bed by the force of the water.
What is suspension?
Small particles like silt and clay are carried along by the water.
What is saltation?
Pebble-sized particles are bounced along the river by the force of the water.
What is solution?
Soluble materials dissolve in the water and are carried along.
What are meanders?
Large bends in the middle and lower courses of a river.
What are flood plains?
The flood plain is the wide valley floor on either side of a river which occasionally gets flooded.
What are levees?
Natural embankments (raised bits) along the edges of a river channel.
What are deltas?
Low-lying areas where a river meets the sea or a lake.
What do the contour lines of a map tell us? What colour are they?
The height of a map (by the number beside them, m) and the steepness of the land (the closer they are, the steeper the slope). They are orange.
Give a couple of characteristics for lanforms if
a) there are no contour lines around a river
b) close contour lines
c) there are black, blocky lines and close contour lines.
a) no contour lines around a river - a flood plain.
b) close contour lines - steep.
c) black, blocky lines = cliff and close countour lines could be a waterfall.
Give 3 impacts of wetter climates on rivers.
Higher discharge because there is more water.
Increase of rate of erosion, more volume of water = more power.
Transportation increases because more energy to carry material.
What is river discharge?
The volume of water that flows in a river per second.
What is hard engineering? Give on example, and a disadvantage.
Man-made structures built to control the flow of rivers and reduce flooding. Flood walls - expensive and can block view of river.
What is soft engineering? Give an example.
Schemes set up using knowledge of a river to reduce effects of flooding. River restoration - making the river more natural, e.g. by removing man-made levees so that flood plain can flood naturally.
When river restoration occurs, why is there less risk of flooding downstream?
There’s less risk of flooding downstream because discharge is reduced.
