Rivers Flashcards
(41 cards)
Precipitation
water falling from the clouds
Evaporation
water turning into water vapor
condensation
water vapor rising into the clouds
Transpiration
water evaporiting from plants
surface runoff
when water stays on the ground
Ground water
when water flows over the earths surface
9 steps of waterfall formation
1) hard rock and soft rock.
2) soft rock erodes quicker.
3) Notch Develops
4) Erosion makes the notch deeper
5) Plunge pool develops
6) No support for hard rock on top
7) Hard rock collapses into plunge pool
8) This process repeats and the waterfall retreats
9) A gouge is formed as the waterfall retreats
Hydraulic action
the shear force of the water
abrasion
When rocks act as sand paper on the river bed
Attrition
rocks colliding with each other
Solution
when rocks dissolve
Suspension
light material is carried along by the river
Traction
Large boulders rolling across the river bed
Saltation
small pebbles and stones are bounced along the river bed
River source
Were the river starts
River mouth
were the river meets the ocean/sea
8 steps to oxbow lakes
1) a meander stars as a slight bend. water flows faster on the outside of the bend than on the inside.
2) the outside of the bend is eroded away. Material is deposited on the inside of the bend
3) This erosion and deposition turns the bend into a meander.
4) The meander bends more and more over the years until it becomes a really tight loop.
5) When the water level is really high, the river has enough energy to go straight across the loop, rather than around it.
6) This is called a meander cut-off
7) The river keeps to its new channel so the loop is left as an oxbow lake
8) After a long, the oxbow lake silts up and dries out and plants grow in it.
Heavy rainfall
Heavy rainfall causes flooding because there is a lot and a lot of water which leads to ground water witch then leads to the river causing it to exceed it max capacity
urbanisation
The more people the higher the demand for house’s pipes and drains and gutter lead to a sewer that leads to the river. the river could eventually get too much water from cities and towns and causes the river too flood
Deforestation
Trees are being cut down, tree’s usually intercept the water and absorb it. when the trees are cut it gets to the river to quickly because there is more ground water which causes the river to overflow
Snow melting
After the winter season when the snow starts to melt the rivers exceed capacity because there is an excessive amount of water that came from the snow.
Flood management
ways to prevent floods
Hard engineering
is more expensive that soft engineering and is usually short term
Soft engineering
is cheaper than hard engineering and is more of a long term solution