Rivers Flashcards
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
Dams
Dams are a type of hard engineering. These trap and store water to reduce surface runoff as water is released in a controlled way.
Embankments
Embankments are a type of hard engineering. These are raised banks along the river, they effectively make the river deeper so it can hold more water before it floods
wash lands
Wash lands are a type of soft engineering. these are parts of the floodplain that are allowed to flood. they can’t be built on. they’re usually used for sports pitches or nature reserves.
Land-use zoning
Land-use zoning is a type of soft engineering. This is were no one can build on a certain place depending on the decision of the government and the risk of flooding
Flood walls
Flood walls are a type of hard engineering. Flood walls are built around settlements and important factories or roads.
Straightening and deepening the river
Straightening and deepening the river is a type of hard engineering. This is when the river is made straighter to make the river flow and channel flow faster so there is less chance of river flooding
Storage Areas
Storage areas are a type of hard engineering. Water can be pumped out of the river and stored in temporary lakes then it is pumped back in after the water in the river has gone down a bit
Afforestation
Afforestation is a type of soft engineering. Afforestation is the deliberate and planned planting of various greenery (more specifically trees)
Warning systems
warning systems are a type of soft engineering. warning systems are issued by the Environment agency so that local people can put sand bags by their homes, take furniture upstairs, or even evacuate the area.
Delta
A flat area at the mouth of a river made of sediment deposited by the river
confluence
a place in the river were water flows together and goes to the tributaries
tributaries
a stream that flows into a main stem
Valley
an area with higher land on each side
Estuary
The estuary is when the fresh water mixes with the salt water (usually at the mouth)
Flood plain
the flat land beside the river which may flood
Watershed
the dividing line between two river basins
river basin
the river basin is were if water were to be there it would end up in the rivers river basin that it is in
