Rivers Flashcards
The river starts at the what
Source
The river ends at the what
Mouth
The hydrological cycle shows how water is what
Stored and moves around the environment
(Shows the continuous circulation of water)
Name for when water moves through soil
Percolation
What is percolation
Where water moves through the soil
What is surface run off
Water flows along the ground and into the river
Name for when water flows along the ground and into the river
Surface run off
Water enters a cycle through what
Precipitation
True or false, precipitation is only rainwater
False
It can also be sleet/ snow/ hail etc
When water enters a cycle through precipitation what else can happen apart from the water going straight into the river
Intercepted by leaves in tree and stored there
Land on ground and infiltrate into soil/ absorbed by tree roots
Move through rock layer
Flow along ground into river (surface run off)
On hot day be evaporated into water vapour (rises up into air and cools and condenses to form rain clouds so the whole cycle repeats)
What is a confluence
Where 2 rivers join
Name for where 2 rivers join
Confluence
What is a tributary
Smaller river that joins the larger/ main river
Name for smaller river that joins the main/ larger river
Tributory
What is meant by the drainage basin
Area of land drained by the river
(Each different drainage basin has a different river that all the water drains into)
Name for boundary of drainage basin
Water shed
Watershed meaning
Boundary of drainage basin
How many different courses (sections) do rivers have
3
Names for 3 sections of river
Upper course (closest to source)
Middle course
Lower course (closest to mouth)
What does a long profile of the river show you
How the gradient of the river changes over the 3 courses (side on view of river) from the source to the mouth
What does the cross profile of the river show you
What a cross section of the river looks like at each of the 3 different courses (as if you’re standing in the river and looking straight up the river)
Features of upper course of river
Hilly
Very Steep gradient
Rapids (noisy)
V shaped valley
Waterfalls
Vertical erosion
Less human settlement
Least water
Why is there less human settlement in the upper course of the river
The land is very steep so hard to build on/ access
Which section of the river has the most water and which has the least water and why
Upper course= least
No other rivers/ tributary’s have joined it yet which will then add more water
Lower course= most
Lots of water has been added to it as other rivers join etc
Vertical erosion meaning
High energy erosion downwards into the land
It deepens the river making it v- shaped
(Most common in upper course of river)
Lateral erosión meaning
Side to side erosion that makes the river wider
More common in middle and lower course of river
In what section of the river does it start to meander
Middle
Which section of the river has the most energy and which has the least
Most= lower course (as river is fastest)
Least= upper course
Which section of the river has the most human settlement and which has the least
Most= lower course (flat land)
Least= upper course (steep land so harder to build on)
Which part of the river does vertical erosion mostly occur in
Upper course
(Eroding downwards)
Which part of the river does lateral erosion mostly occur in
Middle and lower course
(Eroding side to side)
Which type of erosion deepens the river channel/ valley
Vertical erosion
Which type of erosion widens the river valley/ channel
Lateral erosion
Which section of the river had the most energy and which has the least
Most= upper course
Least= lower course
3 upper course river landforms
Waterfalls
Gorges
Interlocking spurs
Waterfalls form in the upper course when the water flows over a layer of … rock and then a layer of…rock
Hard
Soft
For waterfalls to form does the water first flow over the layer of hard rock or the layer of soft rock
Hard first
Then soft
What happens in the upper course of the river when the water first flows over the layer of hard rock then soft rock
The soft, less resistant rock is eroded by hydraulic action and abrasion creating a ‘step’ (very steep gradient)
As water flows over the ‘step’ more and more of the soft rock is eroded creating a very steep drop (waterfall)
What process happens after the waterfall (steep drop in the river) is formed
The hard rock is undercut by erosion so becomes unsupported and collapses creating a plunge pool at the foot of the waterfall
What happens once the plunge pool has been formed in waterfall formation process
Overtime more undercutting of the hard rock occurs due to erosion so the waterfall retreats creating a gorge (long stretch of river surrounded by steep sided valley)
What is a gorge
Long stretch of river surrounded by steep sided valley
What part of the river are waterfalls and gorges found in
Upper course
What is a waterfall
Steep drop in the river (found in the upper course)
Are waterfalls formed by erosion or transportation
Erosion
Which process in the upper course creates steep sided v-shaped valleys
Vertical erosión
Vertical erosion creates what type of valley in the upper course of the river
V-shaped, steep sided valley
What are interlocking spurs
Bands of slightly tougher rock/ land that the river moves around (hillsides that interlock)
What 2 types of processes form meanders
Erosión
Deposition
Does erosion occur on the inside or outside of the bend
Outside
Does deposition occur on the inside or outside of the bend
Inside
True or false, in meanders there are both deep and shallow sections
True
(Deep on outside)
(Shallow on inside)
Why does the current flow faster on the outside of the bend
Channel is deeper so less friction occurs to slow it down
Therefore more erosión takes place forming river cliffs
Are river cliffs found on the inside or outside of the river bend
Outside
(River is deeper so less friction occurs so water moves faster so outside of bend is eroded)
Are river cliffs formed by deposition or erosion
Erosion
What forms on the inside bend of the river
Slip off slope
How do slip off slopes form on the inside bend of the river
River is shallower so more friction occurs so water moves more slowly
Eroded material is deposited on the inside of the bend forming slip off slopes
Are river cliffs on the outside of the bend formed by vertical or lateral erosión
Lateral
Including hydraulic action and abrasion so the river bank is undercut
Process for formation of oxbow lake
Occurs in a meander
Velocity is fastest on outside of bend as river is deeper so there is less friction
During storm conditions velocity and discharge of river increase so there is a higher rate of erosion on the outside bend including abrasion and hydraulic action
This lateral erosión causers the neck of the meander to become very narrow until eventually teh river has enough energy that it breaks through the neck
Instead of the river flowing the whole way around the bend like before, it now takes the new shorter, more direct route that has just been created
Deposition occurs along the sides of the river to seal off the existing meander leaving an oxbow lake
Overtime the lake can fill with slit forming marshland/ the lake dries up leaving a meander scar
How is a meander scar formed from an oxbow lake
The oxbow lake eventually dries up
Thalweg meaning
Line of fastest flow in the river
In meanders there are alternating sections of deep water and shallower water.
What are the deep and shallow sections called
Steep= pool (usually outside of bend)
Shallow= Riffle (usually inside of bend)
Is the riffle deep or shallow
Shallow
Is the pool deep or shallow
Deep
3 depositional landforms
Floodplain
Levee
Estuary
Which course of the river are depositional landforms found in (estuaries, floodplains, levees)
Lower course
What is a floodplain
Area of open, flat land surrounding river in middle and lower course
Where are estuaries found
Lower course at the mouth of the river where it meets the sea
3 natural causes of a river flooding
Geology
Relief
Precipitation
2 human causes of rivers flooding
Deforestation
Growth of urban areas
4 types of hard engineering
Embankments
River straightening
Dam and reservoir
Flood relief channels
4 types of soft engineering
Afforestation
Flood warnings
Floodplain zoning
River restoration
Where is the River Tees located
North East of England
Flows through Durham and Yorkshire
Starts at Cross Fell, ends at the North Sea
Features of hydrograph
Peak discharge (time when river has maximum discharge) (top of curve)
Peak rainfall (hour when there was the greatest amount of rainfall)
Rising limb- time taken between start of rainfall and river reaching maximum (peak) discharge
Falling limb- time taken between peak discharge and river reaching normal flow
Lag time (time between peak rainfall and peak discharge)
Normal flow- base flow of river
What does a hydrograph show
How a river responds to a period of rainfall
What is River Tees a case study of
Examples of landforms in the upper, middle and lower course of the river
1 key upper course river landform in River Tees
High Force waterfall
3 key river landforms in river Tees
High force waterfall (upper course)
Sockburn (meander) (middle course)
Teesmouth (estuary) (lower course)
1 key middle course landform in River Tees
Sockburn (meander)
1 key lower course landform in River Tees
Teesmouth (estuary)
Key facts about High force waterfall (Upper course landform in River Tees)
700m long gorge
Popular tourist attraction
Hard rock= whinstone
Soft rock= limestone
Largest waterfall in UK by discharge
Key facts about Teesmouth (estuary in lower course of River Tees)
Teesport (shipping port built on reclaimed land)
Teesmouth National Nature Reserve (for migratory birds and seals)
