Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Geography > River Landscapes > Flashcards

River Landscapes Flashcards

You may prefer our related Brainscape-certified flashcards:
U.S. Geography flashcards World Geography flashcards
1
Q

What is a drainage basin

A

an area of land drained by a river and its tributaries

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Speed of a river high in the mountains near the source

A

where water is shallow there is friction with the bed and banks, slowing the rate of flow
(unless there are rapids where channel narrows and river becomes deeper, increasing flow)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Characteristics of a river further downstream

A

rivers channel is deeper due to the tributaries bringing additional water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

In which course of the river would there be mostly erosional landforms

A

upper course

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

In which course would you find mostly** desposition** landforms

A

lower

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is hydraulic action

A

the force of water hitting the rivere banks and bed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is abrasion

A

when the load carried by the river repeatedly hits the bed or banks dislodging particles into the flow of the river

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is attrition

A

stones carried by the river knock against each other, gradually making the stones smaller and more rounded

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is solution

A

when river flows over limestone or chald, the rock is slowly dissolved due to the midly acidic river water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Where are larger rocks found in the river course and why

A

upper course because they are too heavy for the river to carry long distances

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are interlocking spurs

A

land made of hard rock jutting out, causing the river to meander

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

How is a waterfall formed

A
  • when a river flows over a resistant rock then less resistant rock
  • the less resistant rock is easily eroded vertically, creating a step and more erosion causes the hard rock to be undercut
  • a plunge pool is created when hyraulic action and abrasion take place
  • erosional processes continue and create a larger overhang of resistant rock
  • eventually the overhanging rock collapses under its own weight, adding rocks and boulders to the plunge pool
  • and the waterfall restreates upsteram
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what is a gorge

+ example

A

narrow steep-sided valley that is usually found immediatly downstream of a waterfall, formed by the gradual retreat of a waterfall
e.g chedder gorge

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

how is a meander formed

A
  • starts with a slight bend in the river.
  • erosion takes place on the outside of the bend where the flow of water is fastest (thawleg)
  • deposition takes place on the inside where flow of water is slow
  • river cliff formed on outside.
  • slip off slope formed on inside
  • process repeats
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

how is an oxbow lake formed

A
  • over time the neck of the meander experiences lateral erosion until it is broken through forming a new straighter channel
  • the old meander loop is cut of by deposition to form an oxbow lake as water takes the shortest route
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is a floodplain and where are they found (which course)

A

wide flate area of marshy land on either side of a river
found in the middle and lower courses

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what are flood plains made of

A

alluvium (a sediment -silt)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

why are flood plains used for farming

A

soils are very fertile

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

how are flood plains formed

A

during a flood, sediment/ silt is deposited as the water loses its energy. layers of sediment builf up over time to form a thick deposit of fertile aluvium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

how and where are levees formed

A
  • occur in the lower course when there is an increase in the volume of water flowing downstream causing a flood
  • during a flood, water flows over the side of the channel, carrying sediment
  • the largest material is deposited first on the river banks and smaller material futher away
  • after many floods, the sediment builds up to increase the height of the river banks
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

why do levees reduce flood risk

A

because they increase the height of the river banks, meaning the channel can carry more water (a greater discharge)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

How is an estury formed and where are they found

A
  • initially formed from rising sea levels
  • estuaries are transitional zones where river meets the sea
  • main process operating in estuaries is deposition meaning sediment is depositedmudflats
  • at low tide deposists form extensive mudflats which develop into natural habitats called saltmarshes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

what is brackish water

A

a mixture of salt water and freshwater

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

where is the river tees

A

River in the North East of England.
It’s source is high in the Pennine Hills and flows east to meet the North Sea

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

what is the water fall in the river Tees called

A

High force waterfall

26
Q

what other river landscapes does the river tees have

A
  • meanders (near Yarm and Barnard castle)
  • levees
  • floodplains
  • large estuary, with mudflats and sandbanks which support wildlife in the area (sites such as Seal Sands are protected areas
27
Q

what is flooding

A

where land that is not normally underwater becomes inundated. Occues when a river channel no longer hold the amount of water flowing in it.

28
Q

physical factors increasing flood risk

A
  • precipitation (torrential rainstorms can lead to sudden falsh floods)
  • geology (rock type) impermaeble rocks speed up water flow
  • steep slopes - encourage a rapid transfer of water towards river channels
29
Q

Human factors of increasing flood risk

(land use)

A
  • urbanisaiton, building on a floodplain creates impermeable surfaces, water is quikly transferred to drains and ewers and then into urban river channels
  • deforestation, trees use water to grow and also store it, when they’re cut down, more water is suddenly available
  • agriculture - soil is left unused and exposed leading to more surface runoff.
30
Q

what does a hydrograph show

A

a graph that plots the river discharge after a storm over time

31
Q

what is the discharge

A

the volume of water flowing along a river

32
Q

what is the lag time on a hydrograph

A

time between the highest rainfall and the highest discharge
it shows how quickly water is transferred into a river channel

33
Q

what is hard engineering

what are its generic costs and benefits

A

involves using man-made structures to prevent or control natural processes from taking place

costs- financial cost and negative impact on environment and peoples lives
benefits- financial savings made by preventing flooding, along with any environmental improvement

34
Q

Dams + reservoirs pros

A
  • can be used to produce electricity by passing water through a turbine within the dam
  • reservoirs can attract tourists
  • effective in regulating water flow
  • used in irrigation
35
Q

how do dams and reservoirs help to prevent floods

A

during periods of high rainfall, water can be stored in the reservoir and then released when rainfall is low

36
Q

Dams and reservoirs cons

A

very expensive
people may have to be displaced to allow construction
habitats are flooded leading to rotting vegetation which releases methane ( a greenhouse gas)

37
Q

channel straightening pros

A
  • used to reduce flood risk in built up/ vulnerable areas
38
Q

what is channel straightening

A

cutting through meanders to create a straight channel, speeding up the flow of water so that high volumes can pass through an area quickly

39
Q

channel straightening cons

A
  • increases flood risk further downstream
  • lining channels with concrete is unattractive and can damage wildlife habitats
40
Q

What are embankments how do they reduce flood risk

A

an artificially raised river bank allows the channel to hold more water before flooding occurs

41
Q

embankment pros and cons

A

pros - when mud is dredged from the river, it is more sustainable and cheaper + looks natural
cons - when concrete or blocks of stone is looks unnatural
- water speeds up which may increase flooding downstream

42
Q

what is a flood relief channel

A

a man-made river channel constructed to by pass an urban area

43
Q

how doe flood relief channel reduce flood risk

A
  • during times of high flow, gates can open to allow excess water to flow away into the relief channel and reduce flood risk
44
Q

cons of flood relief channel

A

expensive to build
if levels continue to rise, the relief channel may also floo

45
Q

what is soft engineering

A

involves working with natural rivver processes to manageflood risk

46
Q

how does afforestation reduce flood risk

A
  • trees obstruct the flow of water and slow down the transfer to river channels
  • water is soaked up by the tree’s or evaporated from leaves and braches
  • tree planting is cheap and has environmental benefits
47
Q

What is flood plain zoning

A
  • restricts different land uses to certain locations on the floodplain
  • areas close to the river and at risk from flooding can be kept clear of high-value land uses such as housing and industry
  • instead these areas can be used for pasture, parkland or playing fields
48
Q

Pros and cons of floodplain zoning

A

pros - reduces overall losses caused by flood damage
cons - can be difficult to implement on floodplains that have already been developed and can cause land prices to fall

49
Q

What is river restoration and how does it reduce flood risk

A

Uses the natural processes and features of a river, such as meanders and wetlands to slow down river flow and rduce the likelihood of a major flood downstream

50
Q

Three levels of flood warning

A

Flood watch - flooding of low-lying areas and roads is expected, people should be prepared and watch water level
Flood warning - there is a threat to homes and businesses. People should move valuable items upstairs and turn off electricity and water
Severe Flood Warning - extreme danger to life and property is expected.

51
Q

How can people prepare for a flood

A
  • Planning (e.g. moving valuable items upstairs)
  • Using flood gates to prevent floodwater from damaging property
  • Use sandbags to keep floodwater away from buildings
52
Q

Where is Banbury

A
  • located in the Cotswold Hills about 50km north of Oxford
53
Q

Why does Banbury need flood management

A
  • Banbury has a history of devastating floods
  • leading to closure of towns railway station
  • shut local roads and caused £12.5 million of damage
54
Q

In which years did Banbury experience extreme floods (2)

A

1998
2007

55
Q

Aspects of Banbury Flood Defence Scheme (embankment)

A
  • 2.9km earth embankment with a maximum height of 4.5m to create a flood storage area
  • Located mainly on the natural flood plan and collects rainwater that otherwise would have swelled the river and caused it to burst its banks
56
Q

Flow control structures in the Banbury embankment

A
  • specially designed opening controls the rate of flow downstream towards Banbury
  • Any excess water backs up behind the structure, filling up the reservoir rather thancontinuing towards Banbury
  • design avoids the need to open and close flood gates
57
Q

Other aspects of Banbury flood defence scheme

A
  • raising A361 road in flood storage area plus improvements to drainage beneath the road to prevent flooding
  • new earth embankments and flood walls to protest property and businesses such as motorsport business Prodrive
  • new pumping station to transfer excess rainwater into river below the town
  • creation of new Biodiversity Action Plan; a habitat with ponds, trees and hedgerows to absorb and store excess water
58
Q

Social benefits of Banbury

A
  • raised road open during floods to avoid disrupting peoples lives
  • quality of life improved with new footpaths and green areas
  • reduced levels of anxiety through fear of flooding
59
Q

Economic benefits of Banbury

A
  • cost was about £18.5 million
  • But by protecting houses and commercial properties, the benefits are estimated to be over £100 million
60
Q

Environmental costs/benefits of Banbury

A
  • Around 100,000 tonnes of earth required to build embankment
  • Biodiversity Action Plan
  • part of floodplain deliberately allowed to flood if river levels are too high, this causes distruction of habitats

Geography (14 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions