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✅👁️Y2 Geography Physical > Paper 1 — Section C — Water Cycle > Flashcards

Paper 1 — Section C — Water Cycle Flashcards

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1
Q

What is the global hydrological cycle?

A

The circulation of water around the Earth — it is a closed system of linked processes so there are no external inputs or outputs, meaning the amount of global water is finite and constant

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2
Q

What is a closed system?

A

Where energy is transferred between the system and its surroundings — no additional inputs
> same amount of water is kept within the system, and is circulated

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3
Q

What is an example of an input into the water cycle?

A

Precipitation from the atmosphere to the ground

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4
Q

The power that drives the global hydrological cycle comes from what 2 sources?

A
  1. Solar Energy:
    Energy from the sun which heats water causing evaporation and transpiration
  2. Gravitational Potential Energy:
    Causes rivers to flow downhill and precipitation to fall to the ground eventually ending up in the sea
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5
Q

What are the 4 stores of water on Earth?

A
  1. hydrosphere
  2. cryosphere
  3. biosphere
  4. atmosphere
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6
Q

What is the largest global store of freshwater? (What%?)

A

The cryosphere: accounts for 69%
(Groundwater holds 30%, biosphere stores 1%)

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7
Q

What are the flows and fluxes between the global stores (annually?)

A
  1. Oceans and Atmosphere
    Evaporation: 400,000
    Precipitation: 370,000
  2. Atmosphere
    Evaporation: 60,000
    Precipitation: 90,000
  3. Land masses and oceans
    Surface runoff 30,000
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8
Q

What is the global water budget? And what percentage of this is freshwater?

A

This takes into account all the water that is held in stores and flows of the global hydrological cycle: only 2.5% of it is freshwater, with only 1% of it being accessible
> 70% is reserved in glaciers

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9
Q

What does ‘residence time’ for water mean? + how does this time vary in the atmosphere, oceans and ice caps

A

The average time a molecule of water will spend in one of the stores — varies from 10 days in the atmosphere to 3600 years in the oceans and 15000 years in an ice cap

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10
Q

What is fossil water?

A

Ancient, deep groundwater made from pluvial (wetter) periods in the geological past

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11
Q

Is water an abundant resource?

A

No it is scarce

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12
Q

What percentage of the worlds water is ocean water?

A

97.5%

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13
Q

What is a drainage basin?

A

An area of land drained by a river and its tributaries

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14
Q

(Inputs) what characteristics of precipitation will effect the drainage cycle?

A
  1. Form:
    Rain, snow or hail
  2. Amount:
    This will affect the amount of water within the basin
  3. Intensity:
    The greater the intensity, the greater the likelihood of flooding
  4. Seasonality:
    The drainage basin system will operate at different flow levels at different times of the year
  5. Distribution:
    This is significant in very large drainage basins I.e the Nile where tributaries start in different climate zones
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15
Q

Name the 7 different flows that are important in transferring the precipitation that has fallen on the land into the drainage network

A
  1. Interception
  2. Infiltration
  3. Percolation
  4. Through flow
  5. Groundwater flow
  6. Surface runoff
  7. River or channel flow
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16
Q

What is interception? (Flow)

A

The retention of water by plants and soils which is subsequently evaporated or absorbed by the vegetation

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17
Q

What is infiltration? (Flow)

A

The process why which water soaks into, or is absorbed by the soil

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18
Q

What is percolation? (Flow)

A

Similar to infiltration, but a deeper transfer of water into permeable rocks

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19
Q

What is throughflow? (Flow)

A

The lateral transfer of water downslope through the soil

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20
Q

What is groundwater flow? (Flow)

A

The very slow transfer of percolated water through permeable / porous rocks

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21
Q

What is surface runoff? (Flow)

A

The movement of water that is unconfined by a channel across the surface of the ground aka overland flow

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22
Q

What is river or channel flow? (Flow)

A

Takes over as soon as the water enters a river or stream; the flow is confined within a channel

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23
Q

What are the 3 outputs within the hydrological cycle?

A
  1. Evaporation:
    Wheee moisture gets lost directly into the atmosphere
  2. Transpiration:
    Biological process whereby water is lost through the pores of plants into the atmosphere
  3. Discharge:
    aka channel flow into another larger drainage basin, a lake or the sea
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24
Q

What is the mouth of a drainage basin?

A

Where the river flows into a lake, sea or ocean

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25
Q

What is the flood plain within a drainage basin?

A

Land that gets flooded when the river overflowd

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26
Q

What is the confluence within the drainage basin?

A

The point where 2 rivers join

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27
Q

What is the watershed within a drainage basin?

A

An imaginary line that separates one drainage basin from the next

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28
Q

What is the source within a drainage basin?

A

The starting point of the river

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29
Q

What is a tributary within the drainage basin?

A

A smaller river which joins a main one

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30
Q

What physical factors within drainage basins effect inputs, outputs and flows?

A
  1. Climate
    - Influences amount of precipitation
    - Impacts vegetation types
  2. Soils
    - determines the amount of infiltration and through flow
    - influences the types of vegetation
  3. Geology
    -Can impact percolation and groundwater flow (therefore aquifers)
  4. Relief
    - impacts the amount of precipitation
    - slopes can effect the amount of runoff
  5. Vegetation
    - the absence of vegetation has a major impact on the amount of interception, infiltration and occurrence of overland flow
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31
Q

Name the 3 types of rainfall

A
  1. Orographic (Relief) rainfall
  2. Convectional rainfall
  3. Frontal rainfall
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32
Q

What is the process of Orographic rainfall? (From evaporation to rainfall)

A
  1. Warm moist Atlantic air from the southwest reaches the higher ground in the west
  2. It is then forced upwards
  3. As it rises the air cools over the higher ground and condenses, forming clouds which produce heavy rainfall
  4. As you move further east there is less rainfall as there is less moisture
    > leads to a rain shadow in the west of the UK
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33
Q

What is the process of Convectional rainfall? (From evaporation to rainfall)

A
  1. During the daytime the sun heats the land which causes high rates of evaporation
  2. this air rises rapidly, cools and condenses which forms cumulonimbus clouds
  3. These clouds often produce heavy rainfall which can cause flash floods
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34
Q

What is the process of Frontal rainfall? (From evaporation to rainfall)

A
  1. Warmer air from the south meets colder air from the north
  2. As they meet, the warmer (less dense) air is forced upwards above the denser cold air
  3. As this takes place the air cools and condensers forming clouds which lead to rainfall
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35
Q

Which type of rainfall is typical in the east and south of the UK where temps are higher in summer?

A

Convectional rainfall

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36
Q

Which type of rainfall is most common in the UK?

A

Frontal rainfall

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37
Q

How do humans disrupt the natural drainage basin cycle?

A

The accelerate processes like deforestation, changing land use and groundwater extraction etc which mainly affects:

  1. Rivers and drainage
  2. The character of the ground surface (it’s shape, texture etc)

Agriculture consists of ploughing furrows into fields which act as small channels, promoting surface runoff

Deforestation leads to less interception and evapotranspiration, promoting surface runoff

Groundwater abstraction lowers the water table, meaning when it rains the ground can store more water

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38
Q

How does river management disrupt the drainage basin cycle?

A
  • construction of storage reservoirs holds back river flows
  • abstraction of water for domestic flow and industrial use reduces river flows
  • abstraction of groundwater for irrigation lowers water tables
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39
Q

How does deforestation disrupt the drainage basin cycle?

A

The clearance of trees reduces evapotranspiration, yet increases surface runoff and infiltration

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40
Q

How does changing land use (agriculture) disrupt the drainage basin cycle?

A
  • arable to pastoral; compaction of soil by livestock increases overland flow
  • pastoral to arable; ploughing increases infiltration by loosening and aerating the soil
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41
Q

How does changing land use (urbanisation) disrupt the drainage basin cycle?

A
  • urban surfaces i.e tarmac, concrete speeds up surface runoff by reducing percolation and infiltration
  • drains deliver rainfall more quickly to streams and rivers — increasing risk of flooding
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42
Q

Which flows within the drainage basin are most affected by humans?

A
  • evaporation and evapotranspiration
  • interception
  • infiltration
  • groundwater
  • surface runoff
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43
Q

How has deforestation disrupted the Amazonian drainage basin?

A
  • lowered humidities
  • less precipitation
  • more surface runoff than infiltration
  • more evaporation, less transpiration
  • more soil erosion and silt being fed into rivers
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44
Q

What is surface runoff?

A

A flow of water over the grounds surface which occurs when excess rainwater, meltwater etc can no longer infiltrate into the soil

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45
Q

What is the water budget?

A

The annual balance between precipitation, evapotranspiration and runoff (the annual balance between the inputs and outputs)

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46
Q

What is the formula for the water budget?

A

P = E + R +/- S

P: precipitation
E: evapotranspiration
R: runoff
S: changes in storage over a period of time (once a year)

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47
Q

Define blue water

A

Water is stored in rivers, streams, lakes and groundwater in liquid form (visible part of hydrological cycle)

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48
Q

Define green water

A

Water stored in soil and vegetation (invisible part of hydrological cycle

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49
Q

Define rain shadow

A

This exists in the UK because the mountains in the west force the air travelling over the Atlantic upwards.
— the moisture cools, condenses and clouds form and orographical rainfall occurs in the north and west

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50
Q

Name a global example of a rain shadow

A

North of the Himalayas: there is no rainfall (Gobi desert) whereas there is rainfall south of the mountain

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51
Q

What does the water budget (annual balance) indicate when used at a national scale?

A

The amount of water that is available for human use (agriculture, domestic consumption etc)

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52
Q

What does the water budget (annual balance) indicate when used at a local scale?

A

The available soil water (amount of water that can be stored in soil and is available for growing crops)

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53
Q

Define evapotranspiration

A

Process by which water is transferred from the land to the atmosphere by evaporation from the soil and other surfaces / transpiration from plants

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54
Q

What is a river regime?

A

The annual variation in the discharge or flow of a river at a particular point, and is usually measured in cumecs

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55
Q

What factors influence a river’s regime?

A
  • the size of the river and where discharge measurements are taken along it’s course
  • temperatures
  • geology and soils
  • climate
  • vegetation cover
  • manmade structures I.e dams
  • topography
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56
Q

What does a storm hydrograph show?

A

Discharge changes over a short period of time (often no more than a few days).
It plots the occurrence of a short period of rain over a drainage basin, and the subsequent discharge of a river

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57
Q

What are the main features of a hydrograph?

A
  1. Once rain starts, the discharge begins to rise: Rising Limb
  2. Peak Discharge is reached some time after the peak rainfall as water takes time to move over and through the ground to reach the river
  3. Once the input of rainwater into the river starts to decrease, so does the discharge; this is shown by the falling or recessional limb
  4. Eventually the river’s discharge returns to its normal level, or base flow
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58
Q

What is the lag time on the hydrograph?

A

The time interval between peak rainfall and peak discharge

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59
Q

How does urbanisation affect hydrographs?

A
  1. construction work leads to removal of vegetation, which exposes soil
    > bare soil is eventually replaced by a covering of tarmac and concrete (impermeable which increases surface runoff)
  2. The high density of buildings means rainfall on roofs swiftly travels through the gutters
  3. Drains and sewers reduce the distance and time that rainwater travels before meeting a river channel
  4. Urban rivers are often channeled using embankments to guard against flooding — floods which occurred often became more devastating
  5. Bridges can restrain the discharge of floodwater and act as local dams
    > prompts upstream floods
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60
Q

What is the overall impact of urbanisation on flood risk?

A

It increases flood risk, as most settlements are located near rivers

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61
Q

What actions does flood risk management typically involve?

A
  • strengthening the embankments of streams and rivers
  • putting in place flood emergency procedures
  • steering urban development away from high risk areas i.e flood plains
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62
Q

What physical features of a drainage basin may affect the shape of a hydrograph? (think speed of flows, lag time, peak discharge)

A
  • shape:
    A circular basin leads to rapid drainage whereas a long drainage basin will take time for the water to reach the river — speedy flows, short lag time, high peak discharge
  • topography & relief:
    The steeper the basin, the more quickly it drains. Indented landscapes will collect water and reduce runoff rates — speedy flows, short lag time, high peak discharge
  • heavy storms:
    Runoff will increase after soils get waterlogged which means water will reach the channel quicker — speedy flows, short lag time, high peak discharge
  • lengthy rainfall:
    This leads to the ground being saturated and runoff will increase, meaning water will reach the channel quicker — speedy flows, decreased lag time, high peak discharge
  • vegetation:
    Can reduce discharge as it intercepts precipitation, roots of plants can also take up water that goes into the soil — speedy flows, decreased lag time, high peak discharge
  • rock type:
    Impermeable rocks encourage greater amounts of surface runoff — speedy flows, decreased lag time, high peak discharge
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63
Q

What factors would lead to a flashy river on a hydrograph?

A
  1. Intense storms
  2. Impermeable rocks
  3. Low infiltration rate soils
  4. High steep slopes which promote surface runoff
  5. Small basins
  6. Circular basins have shorter lag times
  7. Low vegetation cover
  8. Urbanisation producing permeable concrete and deforestation which reduces interception
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64
Q

What factors would lead to a flat river on a hydrograph?

A
  1. Steady rainfall
  2. Permeable rocks
  3. High infiltration rate
  4. Low gentle slopes
  5. Larger basins
  6. Elongated basins
  7. Dense vegetation cover
  8. Low population density, reforestation, less impermeable surfaces etc
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65
Q

What are the characteristics of a high pressure system

A
  • the air is sinking
  • no moisture in the air
  • no clouds
  • no rain
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66
Q

What are the characteristics of a low pressure system

A
  • the air is rising
  • moisture in the air
  • clouds
  • rain
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67
Q

Define a drought

A

A shortfall or deficiency of water over an extended period, usually at least a season

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68
Q

Define a hydrological drought

A

Where there is reduced stream flow, lowered groundwater levels and reduced water stores

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69
Q

Define an agricultural drought

A

When agricultural activity is greatly impacted by a drought (could lead to food shortages)

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70
Q

List the inputs and outputs of the water budget

A

inputs:
- precipitation
- water diversion into the area
- groundwater flow into the area
- surface water flow into the area
- surface runoff into the area

outputs:
- evapotranspiration
- water diversion out of the area
- groundwater flow out of the area
- surface water flow out of the area
- surface runoff out of the area
- industrial or residential uses within the area

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71
Q

List the human and physical factors which affect the soil moisture budget

A

human:
- groundwater abstraction to provide water supply
- arable farming
- urbanisation

physical:
- vegetation cover and type
- amount, intensity and type of precipitation
- soil properties: permeability etc
- temperature
- antecedent soil moisture: amount of water already in the soil

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72
Q

What are simple river regimes?

A

These are where the river experiences a period of seasonally high discharge, followed by low discharge

> typical of rivers where the inputs depend on glacial meltwater
I.e rivers with temps that rise in mountainous regions

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73
Q

What are complex river regimes?

A

These are where larger rivers cross several different relief and climatic zones, and therefore experience the effects of different seasonal climatic events

> human factors I.e damming can also contribute towards complexity

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74
Q

Define soil throughflow

A

Water which slowly moves downhill in the top layer of soil

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75
Q

Define a meteorological drought

A

Based on the degree of dryness / rainfall deficit and the length of the dry period

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76
Q

Define a socio-economical drought

A

Where demand for water exceeds water availability — could be weather related or due to overuse of resources

> depends on temporal and spatial variations in supply and demand

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77
Q

How many types of drought are there?

A

4

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78
Q

What are the major deficits which occur during each of the 4 drought types?

A
  1. Meteorological drought
    Rainfall deficit
  2. Hydrological drought
    Stream flow deficit
  3. Agricultural drought
    Soil moisture deficit
  4. Socio-economical drought
    Food deficit
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79
Q

What is the name given to high pressure weather systems?

A

Anticyclones

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80
Q

What other impacts can anticyclones have and what are they called?

A

Blocking anticyclones which lead to droughts

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81
Q

What would happen as a result of reduced soil moisture? (During droughts when any rain which does fall quickly gets absorbed by plants)

A

The ground drys leading to crack
— less water in the water tables
> no recharge

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82
Q

What does ENSO stand for?

A

El Niño Southern Oscillation

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83
Q

In short, what is meant by ENSO?

A

This is a recurring climate pattern involving changes in the temperature of waters in the central and eastern tropical Pacific Ocean

> causes a variation in the ocean temps and winds
effects the climates in the tropics

84
Q

Is El Niño or La Niña cooling or warming of sea temperatures?

A

El Niño: warming
La Niña: cooling

85
Q

How often does El Niño occur and how long is its duration?

A

Occurs every 3-8 years, lasts for 14-22 months

86
Q

What is the Walker cell?

A

The circulation of air whereby upper atmospheric air moves eastwards, and surface air moves west across the Pacific, causing trade winds
CLOCKWISE DIRECTION

87
Q

What happens to the intensity of the walker cell during La Niña?

A

The normal conditions are intensified

Low pressure over the west pacific becomes lower, and high pressure over the eastern pacific becomes higher

  • rain increases over SE Asia
  • droughts in South America
88
Q

What is the Southern Oscillation Index (SOI)? (What does it track)

A

Gives an indication of the intensity and development of El Niño or La Niña events — tracks atmospheric pressure

89
Q

What are the normal conditions in the pacific basin? (Think wind direction, water warmth, direction of water cell)

A
  • trade winds blow east to west along equator
  • warm water builds up on NE coast of Australia and Indonesia
    > warm air rises: CCC
  • walker cell goes in normal direction
90
Q

What is happening on the west coast of South America during normal conditions in the pacific?

A

Cold air sinks: high pressure — no moisture is present
> results in droughts (no CCC)

91
Q

What is happening on the east coast of Australia during normal conditions in the pacific?

A

Warm air rises: low pressure — moisture present; CCC
> rain and monsoons in Australia
Tropical storms occur in normal conditions

92
Q

What are the El Niño conditions in the pacific basin?

A
  • trade winds weaken / reverse so water goes eastwards
  • change in ocean temps causes walker cell to break down
93
Q

What is happening on the west coast of South America during El Niño conditions in the pacific?

A

Warm air builds up — lower pressure: more evaporation as warm air rises
> CCC

94
Q

What is happening on the east coast of Australia during El Niño conditions in the pacific?

A
  • more droughts / no rain in eastern oz
  • more heatwaves
  • higher pressure
  • larger frost season
  • fewer tropical cyclones
95
Q

What are the La Niña conditions in the pacific basin?

A
  • trade wins are stronger: MORE INTENSE / ENHANCED normal conditions
  • larger areas of warm water
    > more storms
    > warm air rises much quicker
    > torrential downpours
    > creates a feedback loop
    > enhanced east > west
96
Q

What is happening on the west coast of South America during La Niña conditions in the pacific? Is it a good time for fishermen?

A
  • good for fishermen for a year — more nutrient rich waters
    > cooler waters which draw up more fish from deep down
97
Q

What is happening on the east coast of Australia during La Niña conditions in the pacific?

A
  • higher risk of flooding in Australia — lower daytime temps
  • more tropical cyclones
98
Q

Which out of El Niño and La Niña follows the other?

A

La Niña sometimes follows after El Niño

99
Q

What are the human causes of a drought?

A
  1. overabstraction
    Amount of water taken is greater than the amount of water falling as rain
    > results in sinking water tables, higher costs etc
    > sometimes there is an intrusion of saltwater from the sea into the water table / aquifer
  2. overgrazing
    Excessive grazing which damages grasslands — plants eaten fast than they replenish
  3. over-cultivation
    Excessive farming on a piece of land to the point of degradation of the soil as well as the land itself
100
Q

Define an aquifer

A

Body of permeable rock which can contain or transmit groundwater

101
Q

As a flow diagram, list the factors leading to desertification

A

Global warming
⬇️
Rising temps, less rain, strong winds
⬇️
More evaporation
⬇️
Vegetation dies (lack of moisture)
⬇️
No veg cover to protect soil — overly exposed to the sun
No roots to hold the soil together
⬇️
The soil dries out easily / erodes

102
Q

Define desertification

A

The type of land degradation in dry lands — fertile land changes into a desert by losing its flora and fauna

103
Q

What 4 key human factors enhance the earths droughts?

A
  1. Population growth
    Rapid growth puts pressure on the land to grow more food
  2. Overgrazing
    Too much cattle destroys vegetation cover
  3. Overcultivation
    Intense use of marginal land exhausts the soil and crops won’t grow
  4. Deforestation
    Trees are cut down for fuel, fencing and housing — roots no longer bind the soil
    > erosion
104
Q

What % of the earths surface do wetlands cover?

A

10%

105
Q

What important functions do wetlands perform?

A
  • they act as temporary water stores
  • they recharge aquifers
  • they act as giant filters trapping pollutants
  • they provide nurseries for fish
  • they are feeding sites for migrating birds
106
Q

What impact will droughts have on wetlands?

A

Less precipitation, less interception (vegetation will become stressed), less infiltration, less percolation
> water tables will fall
> evaporation will increase
> this will reduce the valuable functions performed by the wetlands

107
Q

What significant impact do forests have on the hydrological cycle?

A

They are responsible for interception > leads to reduced infiltration and overland flow

108
Q

How does deforestation impact the water cycle?

A
  • flood peaks become higher and lag times become shorter
  • infiltration is decreased
  • increased discharge leads to flooding
  • more eroded material is carried in rivers i.e silt and clay in suspension
  • annual rainfall is reduced and the seasonality of rainfall decreases
109
Q

How does deforestation impact soil health?

A
  • runoff and erosion is increased
  • raindrop impact washes finer particles of clay and humus away
  • coarser and heavier sands are left behind
  • CO2 is released from decaying woody material
  • biomass is lost due to reduced plant growth and photosynthesis
  • rapid soil erosion leads to a loss of nutrients
  • increased leaching — loss of minerals
110
Q

How does deforestation impact the atmosphere?

A
  • reduced evapotranspiration makes the air less humid
  • reduced shading leads to more direct sunlight reaching the forest floor
  • increased turbulence as the heated ground induces convectional air currents
  • the air is drier
  • evapotranspiration rates from the resultant grasslands are about one third that of TRF
  • oxygen content is reduced and transpiration rates are lowered
111
Q

How does deforestation impact on the biosphere?

A
  • biomass is lost because of reduced plant growth and less photosynthesis
  • the decrease in habitats means fewer animal species survive
  • evaporation from vegetation is reduced
  • less absorption of CO2 means a reduced carbon store
112
Q

What are the meteorological causes of flooding?

A
  • intense storms
    > leads to flash flooding
  • prolonged, heavy rain i.e during the Asian monsoon and with the passage of deep depressions across the UK
  • rapid snowmelt during a particularly warm spring
113
Q

What other physical circumstances increase the likelihood of flooding?

A
  • low-lying areas with impermeable surfaces like cities
  • where the ground surface is above impermeable rocks
  • when ice dams suddenly melt and the waters in glacial lakes are released
  • where volcanic activity generates meltwater beneath ice sheets that is suddenly released: Jokulhlaups
  • where earthquakes cause the failure of dams or landslide that block rivers
114
Q

What are the human causes of flooding?

A
  • impermeable surfaces I.e tarmac
  • dams
  • ploughing — compacts soil
  • cattle farming — compacts soil
  • deforestation
  • sewers feed water into channels
  • river mismanagement — channelisation, damming, river embankments
115
Q

What are the socio-economic impacts of flooding?

A
  • death / injury
  • spread of water borne diseases
  • trauma
  • damage to infrastructure
  • disruption of transport and communications
  • interruption of energy / water supplies
  • destruction of crops
116
Q

What are the environmental impacts of flooding? (Mostly positive)

A
  • recharged groundwater stores
  • increased connectivity between aquatic habitats
  • soil replenishment
  • for many species, flood events trigger breeding, migration and dispersal
117
Q

Are ecosystems resilient to flooding?

A

Most ecosystems have a degree of ecological resilience, however environments that have been degraded by human activities are less resilient i.e the removal of soil and sediment by floodwater can lead to eutrophication, leach pollutants into water etc

118
Q

What is a benefit of underground water stores?

A

Water stored underground cannot evaporate — can be accessed using wells / springs

119
Q

Define saltwater intrusion

A

The movement of saline water into freshwater aquifers — can lead to groundwater quality degradation
> including drink water sources

120
Q

Why does saltwater intrusion happen?

A

If too much freshwater is pumped out of the aquifer system, causing saltwater to seep into the freshwater

121
Q

What is climate change?

A

Long term shifts in temperatures and weather patterns — may be natural or enhanced by human activity

122
Q

Define a climate tipping point

A

A critical threshold where an abrupt, possibly irreversible change to the climate system makes the system move into a very different state

123
Q

What are the 8 possible tipping points, as stated by the Inter-Governmental Panel on Climate Change (IPCC)

A
  1. Atlantic thermohaline circulation collapse
  2. Seabed methane release
  3. Dieback of tropical rainforests
  4. Arctic Ocean free of sea ice in summer
  5. Long term droughts
  6. Dieback of tropical rainforests
  7. Collapse of the monsoon climate circulation
  8. Collapse of the Greenland and / or Antarctic ice sheet
124
Q

What is the effect of melting northern ice sheets on the thermohaline circulation?

A

The melting of northern ice sheets releases significant quantities of light and unsalted freshwater into the ocean
> this freshwater blocks and slows the conveyor belt

125
Q

What impact (temperature wise) will the collapse of the thermohaline circulation have on the world?

A

Temperatures in NW UK:
Decrease by 6-8°C

Temperatures in the northern hemisphere:
Decrease by 2°C

Temperatures at the equator:
Increase by up to 2°C

Temperatures in the southern hemisphere:
Increase by 4°C

126
Q

What tipping point will occur for boreal forests across Europe and Siberia?

A

Trees will no longer be able to sequester enough carbon from the atmosphere, leading to increased levels of greenhouse gases in the atmosphere
> further enhancing global warming

127
Q

What tipping point will occur for TRF across Brazil?

A

There will be more droughts, meaning trees will die — less trees transpiring moisture
> less rainfall
> less sequestering of carbon into the atmosphere
> increased levels of greenhouse gases into the atmosphere

128
Q

How will climate change impact inputs (precipitation) within the hydrological cycle?

A
  • a warmer atmosphere has a greater water-holding capacity
  • higher frequency of droughts in some locations due to longer heatwaves
  • widespread increases in rainfall intensity are expected
129
Q

How will climate change impact outputs (evaporation and evapotranspiration) within the hydrological cycle?

A
  • evaporation over large areas of Asia and North America appears to be increasing
  • transpiration is linked to vegetation changes, which in turn are linked to changes in soil moisture and precipitation
130
Q

How will climate change affect surface runoff and stream flow, and ground water flow?

A
  1. Surface runoff and stream flow
    - more droughts and floods (extreme weather)
    - increased runoff and reduced infiltration
  2. Groundwater flow
131
Q

How will climate change affect flows?

A
  1. reservoir, lake and wetland storage
    - it appears storage is decreasing as temperatures increase
  2. soil moisture
    - where precipitation is increasing, it is likely that soil moisture will increase
  3. permafrost
    - deepening of the active layer is releasing more groundwater
  4. snow
    - spring melt will begin earlier
  5. glacier ice
    - less accumulation because more precipitation is falling as rain
  6. oceans
    - where there is ocean warming, there will be more evaporation
    - more cyclones
    - rising sea level
132
Q

What becomes an issue when forecasting possible changes to the hydrological cycle?

A

Distinguishing between the impacts of long-term climate change and those of short term oscillations associated with ENSO cycles

133
Q

List some factors which are leading to a diminishing water supply and increased uncertainty?

A
  • increases in annual temperature, leading to greater evaporation
  • greater rates of evapotranspiration
  • ENSO cycles are causing unreliable patterns of rainfall
  • more frequent cyclone events threaten water supplies
  • increased intensity / frequency of droughts
  • depleting aquifers
  • loss of snow and glaciers as a store threatens mountainous communities
134
Q

List 4 adaptation strategies to climate change

A
  1. Water conservation + management
  2. Solar radiation management
  3. Land use planning and flood risk management
  4. Residential agricultural systems
135
Q

How does water conservation and management work?

A

The practice of using water efficiently to reduce unnecessary water use
Methods:
- smart irrigation
- smart meters
- recycling sewage water
- recycling used water

136
Q

How does solar radiation management work?

A

Geo engineering involves ideas and plans to deliberately intervene in the climate system to counteract global warming
> use of orbiting satellites to reflect inward radiation back into space

137
Q

How does land use planning and flood risk management work?

A

Not allowed to build on flood plains — no risk of flooding of buildings as they’re not in high risk areas

138
Q

How do resilient agricultural systems work?

A

Seeds are created to be more resilient to hotter climates: genetically modified

139
Q

What are the benefits and drawbacks of water conservation and management?

A

benefits
- less resources used
- attitudinal change is long term — using grey water becomes a lifestyle
- recycled water

drawbacks
- efficiency and conservation cannot match increased demand for water
- impacts clothing industry
- needs Gov enforcement

140
Q

What are the benefits and drawbacks of solar radiation and management?

A

benefits
- offsets human induced warming

drawbacks
- untried and untested
- would reduce but not eliminate
- complex

141
Q

What are the benefits and drawbacks of land use planing and flood risk management?

A

benefits
- soft management
- low cost

drawbacks
- public antipathy
- potentially damages the environment
- some Govs may not be able to fund resistant infrastructure

142
Q

What are the benefits and drawbacks of resilient agricultural systems?

A

benefits
- makes seeds and species more likely to survive
- fewer fertilisers used
- more productive / efficient
- improves soil health

drawbacks
- more expensive
- genetic modification is still debated
- growing food insecurity

143
Q

List the 5 climate change mitigation strategies

A
  1. Carbon taxation
  2. Energy efficiency
  3. Afforestation and reforestation
  4. Renewable switching
  5. Carbon capture and storage
144
Q

How does carbon taxation work?

A

A tax fee or cost paid by users of fossil fuels; which is directly linked to the level of CO2 emissions that the fuel produces

145
Q

How does energy efficiency work?

A

Requires residential / commercial buildings to reduce energy consumption — loans provided to renovate old properties

146
Q

How does afforestation and reforestation work?

A

Planting trees to capture and store more carbon

147
Q

How does renewable switching work?

A

Switching to renewable energy away from non renewable carbon, therefore reducing carbon

148
Q

How does carbon capture and storage work?

A

Technologies that capture greenhouse gases and store them safely underground

149
Q

What are the benefits and drawbacks of carbon taxation?

A

benefits
- increasing levies drives companies away from using fossil fuels

drawbacks
- job losses — shutting industries
- hard to monitor

150
Q

What are the benefits and drawbacks of energy efficiency?

A

benefits
- less energy wasted

drawbacks
- expensive to install unless it is heavily subsidised

151
Q

What are the benefits and drawbacks of afforestation and reforestation?

A

benefits
- restoration of degraded environments
- prevents soil erosion
- provision of forest sinks

drawbacks
- costly
- takes time for trees to grow
- needs lots of land

152
Q

What are the benefits and drawbacks of renewable switching?

A

advantages
- provides intermittent energy
- creates jobs
- clean and renewable
- more energy secure

drawbacks
- lots of land needed
- expensive
- limited lifespan

153
Q

What are the benefits and drawbacks of carbon capture and storage?

A

benefits
- 90% captured
- created employment

drawbacks
- expensive
- leak risk
- needs permeable rock
- not available in all countries

154
Q

Define water insecurity

A

The lack of adequate and safe water for a healthy and productive life and is not able to meet the present and future social, economic and environmental needs of a population

155
Q

Define water security

A

A sustainable supply of clean water which meets the social, economic and environmental needs of a population in a climate of peace and political stability

156
Q

Define water stress

A

When water resources are between 1000-1700 cubic metres per capita, leading to temporary shortages of water use, food insecurity and growing conflict between water users

157
Q

Define water scarcity

A

When water resources are between 500-1000 cubic metres per capita leading to serious water shortages, over extraction of groundwater and insufficient flows to the natural environment

158
Q

Define absolute water scarcity

A

When renewable water resources are very low and less than 500 cubic metres per capita leading to widespread and severe restrictions on water use and rationing

159
Q

Define physical water scarcity

A

Insufficient water to meet demand

  • occurs when >75% of a regions blue water flows are being used
    > currently applies to 25% of global population
160
Q

Define economic water scarcity

A

People can’t afford water, even when it’s available due to lack of technology and good governance

161
Q

Define the world water gap

A

The gap between those countries with water security and those with water insecurity

162
Q

Name some countries which experience absolute water scarcity

A

Saudi Arabia, Algeria and Syria

163
Q

Why do people experience severe water shortages?

A
  • rapid population growth
  • uneven distribution of global supply
  • deterioration in water quality
  • saltwater encroachment at the coast
  • over abstraction from rivers, lakes and aquifers
164
Q

List some supporting evidence that shows water insecurity is a big issue

A
  • 12% of the worlds population consumes 85% of its water
  • 1.8 billion people lack potable water
  • every 90 seconds, a child dies from a water borne disease
  • half of the worlds rivers and lakes are polluted
165
Q

By 2025, population and economic growth is expected to cause an increase in demand for water supplies by how much?

A

20% increase

166
Q

What impacts may water scarcity have on an economy?

A
  • threatens food supplies
  • reduces economic development
  • causes environmental damage
167
Q

What are the 3 main drivers in the demand for water?

A
  1. Population growth
  2. Economic development — agriculture, industry, energy and services
  3. Rising living standards — cleaning, cooking, bathing, swimming pools, washing machines etc
168
Q

What are the 3 main pressures (increasing the risk of water insecurity)?

A
  1. diminishing supply
    - climate change
    - deteriorating quality from pollution
    - impact of competing users
  2. rising demands
    - population growth
    - economic growth
  3. competing demands from users
    - international issues
    - upstream vs downstream
    - HEP vs irrigation
169
Q

List reasons why the price of water may vary

A
  • accessibility
  • Gov regulation
  • availability
  • cost to treat
  • high demand — higher cost
  • wealth of a country
170
Q

What industries use lots of water in production?

A

Industries I.e chemicals, electronics, paper and petroleum all consume lots of water — causes a concern for water pollution

171
Q

What is a water conflict?

A

A conflict between countries or groups over the rights to access water resources. Occurs because of competing demands

172
Q

What are some key causes of water conflict?

A
  • when rivers are international and flow through different countries
  • when upstream users dam, divert or pollute water at the expense of downstream users
  • large dams are built that have a huge ecological impact — prevents flow of silt downstream
173
Q

Who are key players in water conflict on a local scale?

A

Farmers, industrialists and households

174
Q

Why might local scale players be in disagreement with planners, environmentalists and water providers?

A

Because their views differ on how water should be managed

175
Q

What is an Integrated Drainage Basin Management (IDBM)?

A

A holistic approach when the whole drainage basin of a river is considered

176
Q

What do IDBM’s coordinate?

A

Conservation and water management

177
Q

What are SuDS systems?

A

Sustainable Drainage Systems — these have aims to reduce surface runoff in areas of greenfield

178
Q

What are some examples of SuDS systems that can be used to reduce the risk of flooding?

A
  • green roofs — vegetation planted in roofs to increase interception + absorption of rainwater
  • infiltration basins — vegetation depressions designed to store runoff and infiltrate it gradually
  • green pavements — allows water to run through it rather than run off it
  • rainwater harvesting (water butts) — collecting water for later use
  • soakaways — a channel dug which is lined with gravel (permeable)
  • filter drains — trenches filled with gravel, allowing water to infiltrate slowly
  • detention basins — delays storm runoff
  • wetlands — retention areas with marsh / wetland vegetation
179
Q

What are water transfer schemes?

A

Involves the diversion of water from one drainage basin to another, either by diverting a river or constructing a large canal to carry water from one basin to another

180
Q

Are hard engineering solutions the answer to water scarcity?

A
  • schemes are huge and expensive, taking a long time to build
  • they don’t often improve the damaged environment — need to firstly improve environmental laws
181
Q

What are the main aims of sustainable water supply schemes?

A
  • minimise wastage and pollution
  • ensure there is access to safe water at an affordable price
  • take into account the view of all water users
  • guarantee equitable distribution
182
Q

What is a mega dam?

A

Large structure over 15m high, generating over 400 megawatts of power on average

183
Q

What is desalination?

A

The process by which dissolved solids in sea water are partially or completely removed to make it suitable for human use

184
Q

Which countries look to use desalination?

A

Middle Eastern countries which border the sea: Saudi Arabia, Kuwait, Israel and UAE

185
Q

What problems are there with water transfer projects?

A
  • rivers can experience low flow and become polluted — impacts ecosystems
  • climate change can combine with lower flows to lead to water scarcity
  • promotes unsustainable farming
  • nitrate eutrophication — pollution transfer
    > water not potable!!!
186
Q

List 5 soft engineering approaches to water management?

A
  1. Smart irrigation
  2. Drip irrigation
  3. Hydroponic farming
  4. Grey water recycling
  5. Genetically modified crops
  6. Restoration of aquifers
  7. Holistic management
187
Q

What is smart irrigation?

A

Sprinklers get replaced by automated technology

188
Q

What is drip irrigation?

A

Piping that controls the amount of water used — applied directly to the crop: drips onto the root preventing waste

189
Q

What is hydroponic farming?

A

Crops grow within nutrient rich water rather than soil

190
Q

What is grey water recycling?

A

Wastewater from cities is being recycled and applied to crops

191
Q

What are genetically modified crops?

A

Crops which become tolerant to disease, drought etc

192
Q

What is the restoration of aquifers?

A

Allowing water time to recover after contamination

193
Q

What is holistic management?

A

The government manages all water supplies — encourages less usage

194
Q

What are the positives and drawbacks of smart irrigation?

A

positives
- applies correct amount of water — reduces waste
- reduces cost

drawbacks
- small scale
- $200 not affordable to all
- not recycled water

195
Q

What are the positives and drawbacks of drip irrigation?

A

positives
- preserves the right amount of water
- increases productivity by 40-50%
- saves 50% water
- higher yields

drawbacks
- could be costly
- small scale
- can still be impacted by drought

196
Q

What are the positives and drawbacks of hydroponic farming?

A

positives
- 70% less water used
- controller environment — grow all year round
- energy efficient

drawbacks
- expensive — tailored to high end restaurants
- small scale, niche
- mainly for small, limited crops

197
Q

What are the positives and drawbacks of grey water recycling?

A

positives
- reduces waste
- doesn’t need to be potable
- sustainable

drawbacks
- costly to clean and convert to being potable

198
Q

What are the positives and drawbacks of genetically modified crops?

A

positives
- less water used
- yields can withstand future climates
- less irrigation

drawbacks
- unaffordable

199
Q

What are the positives and drawbacks of restoration of aquifers?

A

positives
- replenishes drinking water sources
- no evaporation losses

drawbacks
- unaffordable
- may not work in hot climates

200
Q

What are the positives and drawbacks of holistic management?

A

positives
- reduces water consumption

drawbacks
- takes a while to implement
- people might not listen

201
Q

What is the Integrated Water Resource Management (IWRM)?

A

It emphasises the river basin as a logical geographical unit for the management of water resources — based on achieving a close cooperation between basin users and players

202
Q

What does the IWRM aim to ensure?

A
  • environmental quality of the rivers and catchment
  • that water is used with maximum efficiency
  • an equitable distribution of water among users
203
Q

Is the IWRM effective?

A

It works well on a community level, but not so well for larger basins (especially if an international boundary is in involved)

204
Q

What important international agreements are there? (To settle international disputes over water)

A
  1. Helsinki Rules — with their equitable rules and concepts
  2. UN Economic Commission for Europe — water convention promotes the joint management and conservation of shared freshwater ecosystems
  3. UN Water Courses Convention — offers guidelines for the protection and use of trans boundary rivers
  4. EU Framework Directive — committing members ensure the status of their water bodies, including their marine waters up to 1 nautical mile from shore
205
Q

Which NGO plays a vital role in playing a ‘neutral’ monitoring role of potential conflict situations?

A

World Wide Fund for Nature

206
Q

What are the different flows within the hydrological cycle?

A
  1. Precipitation
  2. Evaporation
  3. Transpiration
  4. Infiltration
  5. Runoff
  6. Through flow
  7. Percolation

✅👁️Y2 Geography Physical (2 decks)

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