Paper 1 — Section C — Water Cycle Flashcards
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
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
3
Q
What is an example of an input into the water cycle?
A
Precipitation from the atmosphere to the ground
4
Q
The power that drives the global hydrological cycle comes from what 2 sources?
A
-
Solar Energy:
Energy from the sun which heats water causing evaporation and transpiration -
Gravitational Potential Energy:
Causes rivers to flow downhill and precipitation to fall to the ground eventually ending up in the sea
5
Q
What are the 4 stores of water on Earth?
A
- hydrosphere
- cryosphere
- biosphere
- atmosphere
6
Q
What is the largest global store of freshwater? (What%?)
A
The cryosphere: accounts for 69%
(Groundwater holds 30%, biosphere stores 1%)
7
Q
What are the flows and fluxes between the global stores (annually?)
A
-
Oceans and Atmosphere
Evaporation: 400,000
Precipitation: 370,000 -
Atmosphere
Evaporation: 60,000
Precipitation: 90,000 -
Land masses and oceans
Surface runoff 30,000
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
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
10
Q
What is fossil water?
A
Ancient, deep groundwater made from pluvial (wetter) periods in the geological past
11
Q
Is water an abundant resource?
A
No it is scarce
12
Q
What percentage of the worlds water is ocean water?
A
97.5%
13
Q
What is a drainage basin?
A
An area of land drained by a river and its tributaries
14
Q
(Inputs) what characteristics of precipitation will effect the drainage cycle?
A
-
Form:
Rain, snow or hail -
Amount:
This will affect the amount of water within the basin -
Intensity:
The greater the intensity, the greater the likelihood of flooding -
Seasonality:
The drainage basin system will operate at different flow levels at different times of the year -
Distribution:
This is significant in very large drainage basins I.e the Nile where tributaries start in different climate zones
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
- Interception
- Infiltration
- Percolation
- Through flow
- Groundwater flow
- Surface runoff
- River or channel flow
16
Q
What is interception? (Flow)
A
The retention of water by plants and soils which is subsequently evaporated or absorbed by the vegetation
17
Q
What is infiltration? (Flow)
A
The process why which water soaks into, or is absorbed by the soil
18
Q
What is percolation? (Flow)
A
Similar to infiltration, but a deeper transfer of water into permeable rocks
19
Q
What is throughflow? (Flow)
A
The lateral transfer of water downslope through the soil
20
Q
What is groundwater flow? (Flow)
A
The very slow transfer of percolated water through permeable / porous rocks
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
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
23
Q
What are the 3 outputs within the hydrological cycle?
A
-
Evaporation:
Wheee moisture gets lost directly into the atmosphere -
Transpiration:
Biological process whereby water is lost through the pores of plants into the atmosphere -
Discharge:
aka channel flow into another larger drainage basin, a lake or the sea
24
Q
What is the mouth of a drainage basin?
A
Where the river flows into a lake, sea or ocean
25
What is the flood plain within a drainage basin?
Land that gets flooded when the river overflowd
26
What is the confluence within the drainage basin?
The point where 2 rivers join
27
What is the watershed within a drainage basin?
An imaginary line that separates one drainage basin from the next
28
What is the source within a drainage basin?
The starting point of the river
29
What is a tributary within the drainage basin?
A smaller river which joins a main one
30
What physical factors within drainage basins effect inputs, outputs and flows?
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
31
Name the 3 types of rainfall
1. **Orographic (Relief) rainfall**
2. **Convectional rainfall**
3. **Frontal rainfall**
32
What is the process of Orographic rainfall? (From evaporation to rainfall)
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
33
What is the process of Convectional rainfall? (From evaporation to rainfall)
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
34
What is the process of Frontal rainfall? (From evaporation to rainfall)
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
35
Which type of rainfall is typical in the east and south of the UK where temps are higher in summer?
Convectional rainfall
36
Which type of rainfall is most common in the UK?
Frontal rainfall
37
How do humans disrupt the natural drainage basin cycle?
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
38
How does river management disrupt the drainage basin cycle?
- 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
39
How does deforestation disrupt the drainage basin cycle?
The clearance of trees reduces evapotranspiration, yet increases surface runoff and infiltration
40
How does changing land use (agriculture) disrupt the drainage basin cycle?
- arable to pastoral; compaction of soil by livestock increases overland flow
- pastoral to arable; ploughing increases infiltration by loosening and aerating the soil
41
How does changing land use (urbanisation) disrupt the drainage basin cycle?
- 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
42
Which flows within the drainage basin are most affected by humans?
- evaporation and evapotranspiration
- interception
- infiltration
- groundwater
- surface runoff
43
How has deforestation disrupted the Amazonian drainage basin?
- lowered humidities
- less precipitation
- more surface runoff than infiltration
- more evaporation, less transpiration
- more soil erosion and silt being fed into rivers
44
What is surface runoff?
A flow of water over the grounds surface which occurs when excess rainwater, meltwater etc can no longer infiltrate into the soil
45
What is the water budget?
The annual balance between precipitation, evapotranspiration and runoff (the annual balance between the inputs and outputs)
46
What is the formula for the water budget?
P = E + R +/- S
P: precipitation
E: evapotranspiration
R: runoff
S: changes in storage over a period of time (once a year)
47
Define blue water
Water is stored in rivers, streams, lakes and groundwater in liquid form (visible part of hydrological cycle)
48
Define green water
Water stored in soil and vegetation (invisible part of hydrological cycle
49
Define rain shadow
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
50
Name a global example of a rain shadow
North of the Himalayas: there is no rainfall (Gobi desert) whereas there is rainfall south of the mountain
51
What does the water budget (annual balance) indicate when used at a national scale?
The amount of water that is available for human use (agriculture, domestic consumption etc)
52
What does the water budget (annual balance) indicate when used at a local scale?
The available soil water (amount of water that can be stored in soil and is available for growing crops)
53
Define evapotranspiration
Process by which water is transferred from the land to the atmosphere by evaporation from the soil and other surfaces / transpiration from plants
54
What is a river regime?
The annual variation in the discharge or flow of a river at a particular point, and is usually measured in cumecs
55
What factors influence a river’s regime?
- 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
56
What does a storm hydrograph show?
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
57
What are the main features of a hydrograph?
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**
58
What is the lag time on the hydrograph?
The time interval between peak rainfall and peak discharge
59
How does urbanisation affect hydrographs?
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
60
What is the overall impact of urbanisation on flood risk?
It increases flood risk, as most settlements are located near rivers
61
What actions does flood risk management typically involve?
- 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
62
What physical features of a drainage basin may affect the shape of a hydrograph? (think speed of flows, lag time, peak discharge)
- **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
63
What factors would lead to a flashy river on a hydrograph?
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
64
What factors would lead to a flat river on a hydrograph?
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
65
What are the characteristics of a high pressure system
- the air is sinking
- no moisture in the air
- no clouds
- no rain
66
What are the characteristics of a low pressure system
- the air is rising
- moisture in the air
- clouds
- rain
67
Define a drought
A shortfall or deficiency of water over an extended period, usually at least a season
68
Define a hydrological drought
Where there is reduced stream flow, lowered groundwater levels and reduced water stores
69
Define an agricultural drought
When agricultural activity is greatly impacted by a drought (could lead to food shortages)
70
List the inputs and outputs of the water budget
**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
71
List the human and physical factors which affect the soil moisture budget
**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
72
What are simple river regimes?
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
73
What are complex river regimes?
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
74
Define soil throughflow
Water which slowly moves downhill in the top layer of soil
75
Define a meteorological drought
Based on the degree of dryness / rainfall deficit and the length of the dry period
76
Define a socio-economical drought
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
77
How many types of drought are there?
4
78
What are the major deficits which occur during each of the 4 drought types?
1. **Meteorological drought**
Rainfall deficit
2. **Hydrological drought**
Stream flow deficit
3. **Agricultural drought**
Soil moisture deficit
4. **Socio-economical drought**
Food deficit
79
What is the name given to high pressure weather systems?
Anticyclones
80
What other impacts can anticyclones have and what are they called?
**Blocking anticyclones** which lead to droughts
81
What would happen as a result of reduced soil moisture? (During droughts when any rain which does fall quickly gets absorbed by plants)
The ground drys leading to crack
— less water in the water tables
> no recharge
82
What does ENSO stand for?
El Niño Southern Oscillation
83
In short, what is meant by ENSO?
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
Is El Niño or La Niña cooling or warming of sea temperatures?
El Niño: warming
La Niña: cooling
85
How often does El Niño occur and how long is its duration?
Occurs every 3-8 years, lasts for 14-22 months
86
What is the Walker cell?
The circulation of air whereby upper atmospheric air moves eastwards, and surface air moves west across the Pacific, causing trade winds
CLOCKWISE DIRECTION
87
What happens to the intensity of the walker cell during La Niña?
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
What is the Southern Oscillation Index (SOI)? (What does it track)
Gives an indication of the intensity and development of El Niño or La Niña events — tracks atmospheric pressure
89
What are the normal conditions in the pacific basin? (Think wind direction, water warmth, direction of water cell)
- 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
What is happening on the west coast of South America during normal conditions in the pacific?
Cold air sinks: high pressure — no moisture is present
> results in droughts (no CCC)
91
What is happening on the east coast of Australia during normal conditions in the pacific?
Warm air rises: low pressure — moisture present; CCC
> rain and monsoons in Australia
Tropical storms occur in normal conditions
92
What are the El Niño conditions in the pacific basin?
- trade winds weaken / reverse so water goes eastwards
- change in ocean temps causes walker cell to break down
93
What is happening on the west coast of South America during El Niño conditions in the pacific?
Warm air builds up — lower pressure: more evaporation as warm air rises
> CCC
94
What is happening on the east coast of Australia during El Niño conditions in the pacific?
- more droughts / no rain in eastern oz
- more heatwaves
- higher pressure
- larger frost season
- fewer tropical cyclones
95
What are the La Niña conditions in the pacific basin?
- 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
What is happening on the west coast of South America during La Niña conditions in the pacific? Is it a good time for fishermen?
- good for fishermen for a year — more nutrient rich waters
> cooler waters which draw up more fish from deep down
97
What is happening on the east coast of Australia during La Niña conditions in the pacific?
- higher risk of flooding in Australia — lower daytime temps
- more tropical cyclones
98
Which out of El Niño and La Niña follows the other?
La Niña sometimes follows after El Niño
99
What are the human causes of a drought?
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
Define an aquifer
Body of permeable rock which can contain or transmit groundwater
101
As a flow diagram, list the factors leading to desertification
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
Define desertification
The type of land degradation in dry lands — fertile land changes into a desert by losing its flora and fauna
103
What 4 key human factors enhance the earths droughts?
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
What % of the earths surface do wetlands cover?
10%
105
What important functions do wetlands perform?
- 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
What impact will droughts have on wetlands?
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
What significant impact do forests have on the hydrological cycle?
They are responsible for interception > leads to reduced infiltration and overland flow
108
How does deforestation impact the water cycle?
- 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
How does deforestation impact soil health?
- 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
How does deforestation impact the atmosphere?
- 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
How does deforestation impact on the biosphere?
- 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
What are the meteorological causes of flooding?
- 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
What other physical circumstances increase the likelihood of flooding?
- 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
What are the human causes of flooding?
- 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
What are the socio-economic impacts of flooding?
- 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
What are the environmental impacts of flooding? (Mostly positive)
- recharged groundwater stores
- increased connectivity between aquatic habitats
- soil replenishment
- for many species, flood events trigger breeding, migration and dispersal
117
Are ecosystems resilient to flooding?
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
What is a benefit of underground water stores?
Water stored underground cannot evaporate — can be accessed using wells / springs
119
Define saltwater intrusion
The movement of saline water into freshwater aquifers — can lead to groundwater quality degradation
> including drink water sources
120
Why does saltwater intrusion happen?
If too much freshwater is pumped out of the aquifer system, causing saltwater to seep into the freshwater
121
What is climate change?
Long term shifts in temperatures and weather patterns — may be natural or enhanced by human activity
122
Define a climate tipping point
A critical threshold where an abrupt, possibly irreversible change to the climate system makes the system move into a very different state
123
What are the 8 possible tipping points, as stated by the Inter-Governmental Panel on Climate Change (IPCC)
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
What is the effect of melting northern ice sheets on the thermohaline circulation?
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
What impact (temperature wise) will the collapse of the thermohaline circulation have on the world?
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
What tipping point will occur for boreal forests across Europe and Siberia?
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
What tipping point will occur for TRF across Brazil?
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
How will climate change impact inputs (precipitation) within the hydrological cycle?
- 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
How will climate change impact outputs (evaporation and evapotranspiration) within the hydrological cycle?
- 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
How will climate change affect surface runoff and stream flow, and ground water flow?
1. Surface runoff and stream flow
- more droughts and floods (extreme weather)
- increased runoff and reduced infiltration
2. Groundwater flow
131
How will climate change affect flows?
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
What becomes an issue when forecasting possible changes to the hydrological cycle?
Distinguishing between the impacts of long-term climate change and those of short term oscillations associated with ENSO cycles
133
List some factors which are leading to a diminishing water supply and increased uncertainty?
- 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
List 4 adaptation strategies to climate change
1. Water conservation + management
2. Solar radiation management
3. Land use planning and flood risk management
4. Residential agricultural systems
135
How does water conservation and management work?
The practice of using water efficiently to reduce unnecessary water use
Methods:
- smart irrigation
- smart meters
- recycling sewage water
- recycling used water
136
How does solar radiation management work?
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
How does land use planning and flood risk management work?
Not allowed to build on flood plains — no risk of flooding of buildings as they’re not in high risk areas
138
How do resilient agricultural systems work?
Seeds are created to be more resilient to hotter climates: genetically modified
139
What are the benefits and drawbacks of water conservation and management?
**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
What are the benefits and drawbacks of solar radiation and management?
**benefits**
- offsets human induced warming
**drawbacks**
- untried and untested
- would reduce but not eliminate
- complex
141
What are the benefits and drawbacks of land use planing and flood risk management?
**benefits**
- soft management
- low cost
**drawbacks**
- public antipathy
- potentially damages the environment
- some Govs may not be able to fund resistant infrastructure
142
What are the benefits and drawbacks of resilient agricultural systems?
**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
List the 5 climate change mitigation strategies
1. Carbon taxation
2. Energy efficiency
3. Afforestation and reforestation
4. Renewable switching
5. Carbon capture and storage
144
How does carbon taxation work?
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
How does energy efficiency work?
Requires residential / commercial buildings to reduce energy consumption — loans provided to renovate old properties
146
How does afforestation and reforestation work?
Planting trees to capture and store more carbon
147
How does renewable switching work?
Switching to renewable energy away from non renewable carbon, therefore reducing carbon
148
How does carbon capture and storage work?
Technologies that capture greenhouse gases and store them safely underground
149
What are the benefits and drawbacks of carbon taxation?
**benefits**
- increasing levies drives companies away from using fossil fuels
**drawbacks**
- job losses — shutting industries
- hard to monitor
150
What are the benefits and drawbacks of energy efficiency?
**benefits**
- less energy wasted
**drawbacks**
- expensive to install unless it is heavily subsidised
151
What are the benefits and drawbacks of afforestation and reforestation?
**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
What are the benefits and drawbacks of renewable switching?
**advantages**
- provides intermittent energy
- creates jobs
- clean and renewable
- more energy secure
**drawbacks**
- lots of land needed
- expensive
- limited lifespan
153
What are the benefits and drawbacks of carbon capture and storage?
**benefits**
- 90% captured
- created employment
**drawbacks**
- expensive
- leak risk
- needs permeable rock
- not available in all countries
154
Define water insecurity
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
Define water security
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
Define water stress
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
Define water scarcity
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
Define absolute water scarcity
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
Define physical water scarcity
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
Define economic water scarcity
People can’t afford water, even when it’s available due to lack of technology and good governance
161
Define the world water gap
The gap between those countries with water security and those with water insecurity
162
Name some countries which experience absolute water scarcity
Saudi Arabia, Algeria and Syria
163
Why do people experience severe water shortages?
- 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
List some supporting evidence that shows water insecurity is a big issue
- 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
By 2025, population and economic growth is expected to cause an increase in demand for water supplies by how much?
20% increase
166
What impacts may water scarcity have on an economy?
- threatens food supplies
- reduces economic development
- causes environmental damage
167
What are the 3 main drivers in the demand for water?
1. **Population growth**
2. **Economic development** — agriculture, industry, energy and services
3. **Rising living standards** — cleaning, cooking, bathing, swimming pools, washing machines etc
168
What are the 3 main pressures (increasing the risk of water insecurity)?
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
List reasons why the price of water may vary
- accessibility
- Gov regulation
- availability
- cost to treat
- high demand — higher cost
- wealth of a country
170
What industries use lots of water in production?
Industries I.e chemicals, electronics, paper and petroleum all consume lots of water — causes a concern for water pollution
171
What is a water conflict?
A conflict between countries or groups over the rights to access water resources. Occurs because of competing demands
172
What are some key causes of water conflict?
- 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
Who are key players in water conflict on a local scale?
Farmers, industrialists and households
174
Why might local scale players be in disagreement with planners, environmentalists and water providers?
Because their views differ on how water should be managed
175
What is an Integrated Drainage Basin Management (IDBM)?
A holistic approach when the whole drainage basin of a river is considered
176
What do IDBM’s coordinate?
Conservation and water management
177
What are SuDS systems?
**Sustainable Drainage Systems** — these have aims to reduce surface runoff in areas of greenfield
178
What are some examples of SuDS systems that can be used to reduce the risk of flooding?
- **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
What are water transfer schemes?
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
Are hard engineering solutions the answer to water scarcity?
- 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
What are the main aims of sustainable water supply schemes?
- 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
What is a mega dam?
Large structure over 15m high, generating over 400 megawatts of power on average
183
What is desalination?
The process by which dissolved solids in sea water are partially or completely removed to make it suitable for human use
184
Which countries look to use desalination?
Middle Eastern countries which border the sea: Saudi Arabia, Kuwait, Israel and UAE
185
What problems are there with water transfer projects?
- 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
List 5 soft engineering approaches to water management?
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
What is smart irrigation?
Sprinklers get replaced by automated technology
188
What is drip irrigation?
Piping that controls the amount of water used — applied directly to the crop: drips onto the root preventing waste
189
What is hydroponic farming?
Crops grow within nutrient rich water rather than soil
190
What is grey water recycling?
Wastewater from cities is being recycled and applied to crops
191
What are genetically modified crops?
Crops which become tolerant to disease, drought etc
192
What is the restoration of aquifers?
Allowing water time to recover after contamination
193
What is holistic management?
The government manages all water supplies — encourages less usage
194
What are the positives and drawbacks of smart irrigation?
**positives**
- applies correct amount of water — reduces waste
- reduces cost
**drawbacks**
- small scale
- $200 not affordable to all
- not recycled water
195
What are the positives and drawbacks of drip irrigation?
**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
What are the positives and drawbacks of hydroponic farming?
**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
What are the positives and drawbacks of grey water recycling?
**positives**
- reduces waste
- doesn’t need to be potable
- sustainable
**drawbacks**
- costly to clean and convert to being potable
198
What are the positives and drawbacks of genetically modified crops?
**positives**
- less water used
- yields can withstand future climates
- less irrigation
**drawbacks**
- unaffordable
199
What are the positives and drawbacks of restoration of aquifers?
**positives**
- replenishes drinking water sources
- no evaporation losses
**drawbacks**
- unaffordable
- may not work in hot climates
200
What are the positives and drawbacks of holistic management?
**positives**
- reduces water consumption
**drawbacks**
- takes a while to implement
- people might not listen
201
What is the Integrated Water Resource Management (IWRM)?
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
What does the IWRM aim to ensure?
- environmental quality of the rivers and catchment
- that water is used with maximum efficiency
- an equitable distribution of water among users
203
Is the IWRM effective?
It works well on a community level, but not so well for larger basins (especially if an international boundary is in involved)
204
What important international agreements are there? (To settle international disputes over water)
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
Which NGO plays a vital role in playing a ‘neutral’ monitoring role of potential conflict situations?
World Wide Fund for Nature
206
What are the different flows within the hydrological cycle?
1. Precipitation
2. Evaporation
3. Transpiration
4. Infiltration
5. Runoff
6. Through flow
7. Percolation
