Water Flashcards
(334 cards)
1
Q
Is the water cycle and open or closed system?
A
closed- no water enters or leaves it
2
Q
What are the driving forces behind the water cycle?
A
gravity and solar energy
3
Q
What are the most important transfers in the water cycle?
A
evaporation and precipitation
4
Q
What is the biggest water store in the world?
A
the oceans- twice the size of any other store
5
Q
Why can underground water be inaccessible?
A
if it’s too deep or if the technology needed for drilling is not available
6
Q
Why are lakes and rivers important stores of water?
A
they are the most accessible for humans
7
Q
What are the drawbacks of using lakes and rivers for water sources?
A
they can be polluted
less than 1% of freshwater is readily available for human use
8
Q
How freshwater is readily available for human use?
A
less than 1%
9
Q
Why is groundwater an important source of water?
A
it is big and it doesn’t evaporate
10
Q
What are the drawbacks of using groundwater as a water source?
A
it can inaccessible especially if not in a wealthy area
11
Q
How are oceans increasingly used as a water source?
A
desalination plants are becoming more popular
12
Q
What is the drawback of desalination plants?
A
they are very expensive
13
Q
How much of Israel’s water has been desalinated from the ocean?
A
30%
14
Q
Why is ice and snow an important water source?
A
its is a very big store of water
it is especially important in glaciated areas where people rely on meltwater streams
15
Q
What are the drawbacks of using ice and snow as a water source?
A
ice and snow is usually in sparsely populated areas and is hard to transport
16
Q
What is an example of an area where people rely on glaciers for water?
A
the Himalayas
17
Q
What is the cryosphere?
A
area covered in ice and snow on the globe
18
Q
what is the biosphere?
A
living things
19
Q
what is fossil water?
A
ground water that is deepest and was filled hundreds of thousands of years ago
20
Q
what percentage of total global water is taken up by the oceans?
A
96.5%
21
Q
What percentage of total global water is freshwater?
A
2.5%
22
Q
What percentage of freshwater is in glaciers and ice caps?
A
68.7%
23
Q
What percentage of freshwater is groundwater?
A
30.1%
24
Q
What percentage of freshwater is surface water?
A
1.2%
25
What percentage of fresh surface water is ground ice/permafrost?
69%
26
What percentage of fresh surface water is in lakes?
20.9%
27
What percentage of fresh surface water is in the atmosphere?
3%
28
What percentage of fresh surface water is in living things?
0.26%
29
What percentage of fresh surface water is in rivers?
0.49%
30
What percentage of fresh surface water is in soil moisture?
3.8%
31
What is an aquifer?
a source of water used by humans that is underground
32
What is the name given to the top of the groundwater?
the water table
33
What is the level below the water table called?
the saturated zone
34
How much groundwater is used a day by American farms?
53 billion galleons a day
35
What impact can humans have on groundwater?
Aquifers can run dry if we use the water faster than the aquifer water levels can replenish through water seeping into the ground
36
What is the residence time for oceans?
3,000- 3,230yrs
37
What is the residence time for glaciers?
20- 800yrs
38
What is the residence time for shallow groundwater?
100- 200yrs
39
What is the residence time for deep groundwater?
10,000yrs
40
What is the residence time for lakes?
50- 100yrs
41
Why are some stores called non renewable stores?
fossil water can be said to be non-renewable as it doesn't replenish fast enough for us to use it
42
What is the residence time for rivers?
2- 6 months
43
What is the residence time for the atmosphere?
9 days
44
how much groundwater is replenished within 50 years?
less than 6%
45
6 reasons why trees are a crucial part of the water cycle
1) they extract water from soil
2) intercept rainfall
3) release water vapour into the atmosphere by transpiration
4) increase infiltration rates
5) stabilise forest albedo
6) stabilise temperatures
46
the cycle of water through trees sustains the atmospheric humidity, which causes...
cloud formation and rainfall
47
By how much has the Farakka dam reduced the flow of the Ganges?
the Farakka dam has reduced the flow of the Ganges into Bangladesh from 200m3/sec to 400m3/sec
48
How does deforestation disrupt the basin hydrological cycle?
it reduces evapotranspiration and water sources in vegetation
49
How does urbanisation disrupt the basin hydrological cycle?
it reduces infiltration rates, and increases surface run off leading to flooding- so there's less water available
50
How much of the Ganges is diverted for use in agriculture?
60%
51
By how much has Coca Cola caused the water tables to fall in India?
In Kerala, India, the water tables have fallen by 6m
52
What is cloud seeding?
Weather modification that that aims to change the amount of type of precipitation by dispersing substances into the air that serve as cloud condensation
53
What is an informal/easy way of describing cloud seeding?
the dropping of crystals into clouds to cause rain
54
What impact does deforestation have on water storage in permeable rocks?
there is more rapid run off of rainwater, so less water is stored in the ground
55
What impact does deforestation have on water storage in soils?
less water is stored in the soil and there is increased soil erosion
56
What impact does deforestation have on water storage in the atmosphere?
Fewer trees causes there to be less transpiration of water vapour into the air
57
What impact does deforestation have on evapotranspiration?
fewer trees= less evapotranspiration
58
What impact does deforestation have on precipitation?
less transpiration means there is less water vapour entering the atmosphere to then condense and fall as precipitation
59
What impact does deforestation have on runoff?
tree litter and roots slows runoff so fewer trees means more runoff
60
What impact does deforestation have on infiltration?
roots increase water infiltration into soil. Deforestation leads to fewer roots, so less infiltration.
61
What happens when soil is saturated (and it rains)?
At peak soil moisture, there is surface run off as there is soil moisture surplus
62
What is a rainshadow?
they are areas on the dry sides of mountains which receive little rain
63
Why do areas in rainshadows receive little rain?
because the air has lost all its moisture from being forced over the mountain (causing it to cool, condense and rain). The air is also forced downwards on the dry side, causing it to warm up so it can't condense and rain.
64
Where is convectional rainfall common?
tropical areas
65
How does convectional rainfall occur?
When the ground is heated by the sun, the air above it becomes warmer, expands, and rises. As it rises, it cools, condenses and rains.
66
Why are there more likely to be flash floods by convectional rainfall in the summer?
The air above the ground rises rapidly as the ground is so hot and the ground is also dry
67
How does frontal/cyclonic rainfall occur?
warm air and cold air meet at a weather front, causing the warmer, less dense air to rise over the colder air. As it rises, it cools, condenses, clouds, and rains.
68
What kind of floods are frontal/cyclonic rainfall likely to cause and why?
Long term floods as it can rain for longer so the ground become saturated
69
When does relief/orographic rainfall occur?
when air travelling over the sea (so it's full of moisture), is forced to rise over a barrier (usually a mountain). As it rises, it cools, condenses, clouds, and rains
70
Why does it rain? (4 steps)
1) Air (containing water vapour) rises
2) It cools by 1 degree for every 100m it rises
3) Condensation occurs
4) if cooling continues it rains
71
By how much does air cool as it rises?
it cools 1 degree Celsius for every 100m it rises
72
What is the drainage basin?
an open system within the global hydrological cycle
73
What is the basin hydrological cycle?
as water cycles through a drainage basin via inputs, outputs, transfers and stores, it creates a basin hydrological cycle
74
What is interception?
water being prevented from reaching the surface by trees or grass (or urban development)
75
What is infiltration?
water sinking into soil/rock from thee ground surface
76
What is percolation?
water seeping deeper below the surface
77
What is throughflow?
water flowing through the soil layer parallel to the surface
78
What is groundwater flow?
water flowing through the rock layer parallel to the surface
79
What is the water table?
the current upper level of saturated rock/soil where no more water can be absorbed
80
What does a lack of vegetation in an area mean for precipitation rates and water availability in that area?
lack of vegetation means a lack of interception therefore less transpiration so little moisture goes back into the atmosphere reducing precipitation rates so less water is available.
81
What effect does impermeable rock have on groundwater storage?
it causes a lack of groundwater storage
82
What effect does thin soil have on water availability in an area?
thin soils means soil can quickly become waterlogged which increases runoff which may lead to flooding- so less water available
83
What effect does deep soil have on water availability in an area?
more infiltration especially if there is veggie cover as roots loosen soils. this maintains soil moisture which improves veggie cover even more. Also, throughflow increases so water reaches lakes and river more gradually- so WATER MORE AVAILABLE
84
How and why do processes and stores in drainage basin vary? (5 points)
Because precipitation varies in 5 ways:
1) form
2) amount
3) intensity
4) seasonality
5) distribution
85
What happens when people move water from stores to crops?
water is removed from the water cycle as the crops grow
86
What can happen to salinity levels in a reservoir as water evaporates?
salinity levels can increase
87
What impacts do grazing animals have on soil and water?
they compact the soil reducing infiltration rates and soil moisture storage, and increasing surface runoff
88
What effect can deforestation have on river flows
it can cause river flows to be more extreme as water is not intercepted and stored by trees
89
How do humans disrupt the drainage basin cycle?
by limiting vegetation storage and by using/limiting groundwater
90
What is desiccation?
the state of extreme dryness or the process of extreme drying
91
How much deforestation occurs in the Amazon every year?
7,500km/year of deforestation from 1970-2013
92
How much of the Amazon forest has been destroyed since 1970?
one fifth of the forest
93
How is the regional rainfall predicted to change in the future in the Amazon?
regional rainfall is predicted to fall by 20%- because the forest is being replaced by grassland
94
How much intercepted water in the Amazon is returned to the atmosphere? and how is this expected to change?
75%- but this is expected to go down to 25% when the forest is cleared
95
Why is the Amazon rainforest being destroyed?
for cattle ranching, large scale commercial agriculture for biofuels and soya beans, urbanisation, and logging
96
What percent of the world's rainforests does the Amazon forest contain?
60%
97
What happens as more water runs off into the Amazon drainage system?
the possibility of severe flooding and mudslides is exacerbated, and aquifers are depleted
98
Describe the river regime of the Rhone
low flow until March
peak until July
gradually falls back to low
99
Describe the river regime of the Guadlana
Highest flow in Jan
| Drops very quickly to low flow in summer then rises again
100
Where is the Guadlana river?
Spain
101
Describes the river regime of the Yukon
No/low flow until March when suddenly peaks to highest flow. Then drops quickly then more gradually.
102
Explain the river regime of the Rhone
The ice starts to melt in Spring causing a rise in flow and the ice and snow cause low flow in winter
103
Explain the river regime of the Guadlana (Spain)
Heat in summer causes river to dry and low flow. May bring heavy floods in late winter with rain
104
Explain the river regime of the Yukon
River frozen in winter so no flow. Surge when river, snow and ground melts
105
What are the river regimes like in equatorial areas?
no dry seasons; heavy rain all year but heaviest in spring and autumn, giving the regime a double peak: _/\/\
106
What are the river regimes like in tropical areas?
distinct wet and dry seasons; high flow soon after rainfall peak; rivers may dry u altogether during the dry season on desert margins: __/\
107
What are the river regimes like in humid mid-latitude areas?
area influenced by the sea have rainfall throughout the years with winter maximum; river flows follow this pattern: \_/
108
What are the river regimes like in Mediterranean areas?
winter rainfall and summer drought; streams dry up in summer but may bring heavy floods in late winter: |_/
109
What are the river regimes like in areas of continental snowmelt?
heavy winter snowfalls cause rapid rise in river levels when thaw comes in spring: |\
110
What are the river regimes like in mountainous areas?
high river flow in spring caused by melting snow and ice; heavy thunderstorms keep river high in early summer: _/\
111
What are the river regimes like in desert areas?
river systems dry
112
If two rivers have the same climate, why might their regimes vary?
If one has impermeable rock causing flow to vary more and one has permeable rock causing flow to be more steady
or dams cause the flow of one to be steady
or trees intercept water causing one flow to be more steady
or one is in an urban area causing its flow to vary more
113
Eight factors affecting storm hydrographs
```
size and shape of catchment
drainage density (tributaries)
weather/climate
rock type
soil
relief
vegetation type
urbanisation/land use
```
114
What is a storm hydrograph?
A storm hydrograph is a way of displaying how the discharge of a river can change over time in response to a rainfall event.
115
What is the lag time? (as shown in storm hydrographs)
the time between peak precipitation in a storm and peak flow of river
116
What are the characteristics of a storm hydrograph of a "flashy" river?
short lag time, steep rising limb (river flow increases quickly), high peak river flow
117
What are the characteristics of a storm hydrograph of a "flat" river?
long lag time, low peak, gentle sloping rising limb (river flow increases slowly)
118
Usually, what is the size of a "flashy" river's catchment?
small- water reaches the river quickly
119
Usually, what is the size of a "flat" river's catchment?
large- water reaches the river slowly
120
Usually, what is the drainage density of a "flashy" river?
fewer tributaries- low drainage density
121
Usually, what is the drainage density of a "flat" river?
many tributaries- high drainage density
122
Usually, what is the rock type of a "flashy" river?
impermeable
123
Usually, what is the rock type of a "flat" river?
permeable
124
Usually, what is the rock type of a "flashy" river?
saturated or completely dry- either way resulting in a lot of runoff
125
Usually, what is the rock type of a "flat" river?
recharging- so able to absorb a lot of water
126
Usually, what is the relief of a "flashy" river?
steep- encouraging river flow to be fast
127
Usually, what is the relief of a "flat" river?
flat- encouraging river flow to be slow
128
Usually, what are the characteristics of vegetation along a "flashy" river?
low lying- not stopping/intercepting water or rain
129
Usually, what are the characteristics of vegetation along a "flat" river?
trees- able to intercept rain and slow down water
130
Usually, what is the land use along a "flashy" river?
farming- no drainage and previous deforestation
131
Usually, what is the land use along a "flat" river?
draining river for water usage- so lots of space for extra water to be added to river
132
Usually, what is the land use along a "flashy" river?
yes- nowhere for the water to drain to and storm drains quickly sends water to river
133
Usually, what is the land use along a "flat" river?
no
134
What does soil moisture recharge mean?
When precipitation is in the process of saturating the soil
| Starts to fill up with moisture again after a period of deficit.
135
What does soil moisture surplus mean?
When the rainfall exceeds the rate of potential evapotranspiration so that there is surface run off and flooding
136
What does soil (moisture) utilisation mean?
When rate of potential evapotranspiration exceeds rainfall after a period of soil moisture surplus so that the surplus moisture is slowly used up
137
What does soil (moisture) deficit mean?
When rate of potential evapotranspiration exceeds rainfall so that there is a deficit of moisture in the soil
138
What is potential evapotranspiration?
an estimate of the amount of water lost through evaporation and transpiration in any given period, depending on temperature and humidity
139
What is a water budget?
the balance between inputs and outputs of water in an area
140
What may happen to soil water availability in the future?
transpiration and evaporation levels will fall as there is less veg due to deforestation leading to less rainfall and therefore less water availability
Soil moisture content will also decline due to land use
141
What is are river regimes?
The annual patterns of a river's flow is called it's regime
142
What are two characteristics of rivers with a simple regime?
One period of seasonally high discharge followed by a low period
Temperate climate where river rises in mountainous area where summer snow melt occurs
143
What are three characteristics of rivers with a complex regime?
experiences a range of seasonal and climatic events, with human factors also adding to the complexity
over travel through a variety or reliefs and climatic zones
encounter very different land uses and population densities
144
Are rivers with simple river regimes long or short?
short
145
Are rivers with complex river regimes long or short
long
146
What are meteorological droughts?
When the amount of precipitation in a specific area is less than average
147
What are meteorological droughts caused by?
lack of rain over a long period of time (precipitation deficiency)- therefore reduced infiltration, run off, and ground water recharge
148
What happens if drought continues for an extended period of time?
there will be water shortages
149
Where can El Nino create droughts?
Indonesia and Australia
150
Where can La Nina create droughts?
North and South America
151
What are hydrological droughts?
they happen after months of meteorological droughts (lack of rainfall)- occurs when there is low water supply
152
What are hydrological droughts caused by?
low levels of precipitation, and an overreliance on water sources for agriculture, industry, etc.
153
What are three human causes of drought?
Soil degradation
Groundwater and surface water use
Deforestation
154
Why does soil degradation occur?
intensive farming ruins soil structure, causing it to not be able to hold and absorb water, resulting in run off and less water being infiltrated and percolated. Because of this, the soil becomes unable to support plant and crop growth
155
Where is soil degradation most common?
regions like Sub Saharan Africa
156
What type of drought does soil degradation most commonly lead to and why?
long term hydrological drought as there is less percolation and infiltration, so less groundwater
157
What are the four types of drought? (in order of severity)
meteorological drought
hydrological drought
agricultural drought
socioeconomic drought/ famine drought
158
What is agricultural drought?
When there is a major deficit of in soil moisture because of water deficits
159
What are the two physical causes of drought?
El Nino and La Nina
| Blocking anticyclones
160
What are blocking anticyclones?
areas of high pressure which remain over a country for a long period of time
161
When the weather/climate systems are normal, in which direction do the trade winds flow?
From South America to Australia (warm current in the oceans follows winds)
162
When the weather/climate systems are normal, where are the cold waters? (South America or Australia)
South America
163
When the weather/climate systems are normal, where are the warm waters? (South America or Australia)
Australia
164
When the weather/climate systems are normal, where are the low pressure systems? (South America or Australia)
Australia- so there is rain there
165
When the weather/climate systems are normal, where are the high pressure systems? (South America or Australia)
South America- so there are no clouds there
166
When was there a serious recent drought in California? (in the 21st century)
3 dry winters in 2007-2009 created drought, leading to a state of emergency called in the state in 2009
167
What impacts were there on employment during the 2009 drought in California?
thousands of farm were laid off
168
Why did the 2009 drought in California impact on the US agriculture industry as a whole?
because California was the largest producer of food and agricultural products in the US in 2009
169
How did the 2009 drought in California impact US avocado production?
the drought lead to a 30% mandatory reduction in water supply for avocado farmers and the taking away of tax incentives for avocado farmers
170
What percentage of US avocados were grown in California?
90% of US avocados grown in California in 2009
171
How did the 2009 drought in California impact electricity production?
California hydropower production declined causing an electricity deficit that had to be made for in $1.7billion worth of natural gas
172
How many wildfires were there in the Western states of the US in 2012? (and what caused them)
lightning started three dozen wildfire in the Western states in 2012 causing the closure of major roads
173
Recently, when has there been a period of extreme dryness in the UK? (in the 21st century)
2004-2006 was one of the driest periods on record for the UK
174
What was banned in the UK 2004 drought and where?
hose pipes where banned in the South East
175
What were 3 physical impacts of the UK 2004 drought?
ground water fell to the lowest level on record
rivers dried up
low river flow meant pollution had greater impact
176
How did the UK 2004 drought impact animals?
fish were more likely to die due to low flow, low O2 levels, and high water temps
177
When was there a drought in the Philippines? (in the 21st century)
2010
178
How many crops were destroyed in the 2010 drought in the Philippines?
$61 million worth of crops were destroyed
179
How much farmland was affected by the 2010 drought in the Philippines?
nearly 400,000 acres of farmland was affected
180
How much food had to be imported into the Philippines during the 2010 drought there?
the Philippines had to import an additional 2.4 million tons of rice
181
What were two impacts of water unavailability during the 2010 drought in the Philippines?
there were low water levels in hydroelectric dams
| buckets were used to recycle bath water to flush toilets
182
Where and what is the Sahel?
vast semi arid region to the Southern edge of the Sahara
183
How has rainfall in the Sahel changed?
They have fallen. Since 1970, rainfall has been below average every year until 2010 apart from 6yrs. From 1900-1970 rainfall was largely above average
184
For how long has there been drought in the Sahel?
40 years
185
What are annual rainfall levels in the Sahel?
It's a transitional climate zone, meaning that annual rainfall is low: 100mm- 80mm/year
186
What impact does El Nino have on Africa?
El Nino can trigger dry conditions in Africa every 7-10 years
187
What percentage of annual rainfall falls in the summer in the Sahel?
85%
188
Explain the positive feedback loop which weakens the monsoon in thee Sahel?
Higher sea surface temps in the South Atlantic and Indian Ocean reduces the difference in temp between the land and sea, and this weakens the monsoon. Less rain means less veg which leads to a change in the colour of the ground from green to beige which reflects more sunlight- so temp difference between land and sea is smaller as land cools so monsoon weakens
189
How has population in the Sahel changed?
30 million people in the Sahel in 1950 but now almost half a billion
190
What has caused the population of the Sahel to grow (3 reasons)?
natural increase
increase of life expectancy and high fertility
armed conflict forcing people to move to desert fringe areas (refugee camps puts strain on areas)
191
How have livestock numbers changed in the Sahel?
Increased by 40% since 1950
192
Why is deforestation occurring in the Sahel? (leading to increased desertification)
deforestation for fuel and home building
193
What percentage of people in the Sahel rely on agriculture?
80%
194
In 2012, by how much did food prices increase in the Sahel due to drought?
food prices doubled in 2012 in the Sahel
195
In 2012, by how much did malnutrition in children increase in the Sahel due to drought?
malnutrition in children rose by 15% in the Sahel
196
In 2012, by how much did crop production decrease in the Sahel due to drought?
crop production feel by 26%
197
How has malnutrition due to the 2012 Sahel drought impacted Burkina Faso?
One third of children in Burkina Faso won't reach full growth potential due to malnutrition caused by the 2012 drought
198
How many droughts had hit the Sahel in the 10 years before the 2012 drought?
the 2012 drought was the third drought to hit the Sahel in 10 years
199
How many people did the 2012 drought in the Sahel effect?
over 10 million people were effected by the 2012 drought in Sahel
200
What happened to donors during the 2012 drought in the Sahel?
In high income countries there was donor fatigue during the 2012 drought in the Sahel, meaning that people only gave money to short-term solutions instead of long term ones
201
What is a wetland?
areas where water covers the soil for all or most of the year.
202
What percentage of the earth's land surface is made up of wetlands?
10%
203
What percentage of the world's wetlands have already been destroyed?
50%
204
What are seven examples of wetlands?
lakes, swamps, rivers, estuary, reservoirs, tidal flats, mangroves
205
What are four things that Ramsar does to protect the wetlands?
look after wetlands
global policies
local projects
educating sustainable use
206
What is Ramsar?
The Ramsar Convention on Wetlands met in 1991 and protects 1800 wetland areas around the world
207
How does drought affect the soil in wetland areas?
soil moisture is reduced and soil structure is lost leading to increased erosion
soil can oxidize and release carbon
208
How does drought affect water quality in wetland areas?
decline in water quality- pollutants more concentrated as less water
209
How does drought affect animals in wetland areas?
loss of species- disrupts food chain
210
How does drought affect water availability in wetland areas?
area of open water reduces and dries out
extreme dryness (desecration) can lead to wildfires
increased flooding- flood storage lost
211
How do wetlands prevent erosion and flooding?
Coastal wetlands act as a buffer between land and sea preventing erosion and flooding
212
How do wetlands improve water quality?
roots of plants in water absorb pollutants and some pollutants stick to soil particles
213
What are three reasons for why wetlands are important?
They act as floodwater storage- slow floods down
3 billion people are dependent on groundwater for drinking
they store carbon
214
How resilient are wetlands to drought?
resilience varies depending on the range and tolerance of plants
many species can recover quickly but long term drought could lead to permanent loss of wetlands and plants
215
In the process of desertification, what happens when the amount of natural vegetation decreases?
there are no plants or leaves to intercept rain, and soil is left exposed to the sun
216
In the process of desertification, what happens when soil is left exposed to the sun?
the sun bakes the soil and it cracks
217
In the process of desertification, what happens when the soil cracks as it's been baked by the sun?
when it rains, the rainwater runs over the surface of the soil rather soaking in
218
In the process of desertification, what happens when the rain is no longer absorbed by the soil?
the soil can often be washed away
219
In the process of desertification, what happens when soil can longer absorb rainwater and is being washed away?
the soil is degraded, losing fertility and structure
220
In the process of desertification, what happens when the soil has degraded?
soil is worn out/poor quality and it is harder to grow crops and natural vegetation
221
In an El Nino year, in which direction do the trade winds flow?
weak trade winds lead to Eastern flow from Australia to South America
222
In an E Nino year, where is are there cold waters? (Australia or South America)
Australia
223
In an E Nino year, where is are there warm waters? (Australia or South America)
South America
224
In an E Nino year, where is are there high pressure systems? (Australia or South America)
Australia- so no clouds
225
In an E Nino year, where is are there low pressure systems? (Australia or South America)
South America- so clouds and rain
226
In an E Nino year, where is are there droughts? (Australia or South America)
Australia
227
In an E Nino year, where is are there floods? (Australia or South America)
South America
228
In a La Nina year, in which direction do the trade winds flow?
trade winds are more intense than usual, flowing from South America to Australia
229
In a La Nina year, where are there warm waters? (South America or Australia)
Australia
230
In a La Nina year, where are there cold waters? (South America or Australia)
South America
231
In a La Nina year, where are there low pressure systems? (South America or Australia)
Australia- so lots of rain
232
In a La Nina year, where are there high pressure systems? (South America or Australia)
South America- so no clouds
233
What is El Nino?
a weather system that lasts 3-7 years and is caused when the trade winds trade direction.
234
In a La Nina year, where are there droughts? (South America or Australia)
South America
235
In a La Nina year, where are there foods? (South America or Australia)
Australia
236
What are the physical causes of flash floods?
occasionally, dramatic floods occur following intense torrential storms. The intensity of the rainfall exceeds the capacity of the river to cope with the amount of water causing flooding
237
When do flash floods in the UK often occur?
in the summer months when there are extreme rainfall events
238
Where and when does monsoon rainfall occur?
monsoon rainfall occurs across South and South east Asia between May and September
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What percentage of annual rainfall occurs during the monsoon?
in general, 70% of average annual rainfall occurs during 100 days of the monsoon
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What happened during the 2016 monsoon in the Philippines?
in July 2016 heavy monsoon rains in the Philippines lead to flooding, landslides and evacuations in villages just to the northwest of the capital (Manila)
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How can snowmelt cause flooding?
flooding can occur when snow melts and the resulting water cannot infiltrate into the soil
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Where does flooding from snowmelt occur?
in the continental interiors of Asia and America
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When did the Norfolk Police report flooding caused by melting snow and ice?
in the winter of 2013 after very mild, wet, and windy weather caused rapid thawing
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What is the usual cause of flooding in the UK?
prolonged and heavy rain associated with low pressure systems
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When does flooding usually occur in the UK?
in autumn or early winter but unusual positions in the jet stream can cause flooding at other times of the year
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What happened in Oct-Dec 2015 in the UK?
intense storms had a cumulative effect on the drainage system causing many rivers to slow at rates up to 50 times higher than normal, some experiencing their highest ever recorded flows
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How do tropical cyclones cause flooding?
they create excess rainfall across river basins
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What is an example of a tropical cyclone causing flooding?
Mozambique in 2000
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How can glacial outburst cause flooding?
Glacial outburst floods occur as ice dams melt (used to hold back flood waters).
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What can floods from glacial outburst lead to?
the draining of glacial lakes
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Where to floods from glacial outbursts most commonly occur?
in the Himalayas
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What exacerbates flooding from glacial outbursts?
landslides or earthquake-induced dam failure
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Why are floods by glacial outburst particularly frequent in Iceland?
because of volcanic activity, which generates melt water beneath the ice sheets and acts as a trigger for ice instability and the sudden release of melt water
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What are floods by glacial outburst known as in Iceland?
jokullhlaup
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What are four secondary physical factors that exacerbate floods?
geology, soil, topography, and vegetation
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How does urbanisation impact flooding?
the creation of impermeable surfaces in urbanisation such as roads doesn't allow any water to sink into the ground
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What is an example of urbanisation creating impermeable surfaces that prevent water from sinking into the ground?
it has been estimated that in London around 25km2 is made up of car parks
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How does drainage in urban areas increase chances of flooding?
sewers and drains allow water to more quickly collect in one place
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How does realignment for urbanisation increase chance of flooding?
straightening channels (realignment) increases chances of flooding downstream by increasing the flow of water
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What is groundwater flooding?
flooding that occurs after the ground has become saturated from prolonged heavy rainfall
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What is surface water flooding?
flooding that occurs when intense rainfall has insufficient time to infiltrate into the soil so flows over land
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What is flash flooding?
a flood with an exceptionally short lag time- often minutes or hours
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What area of the UK was affected by Storm Desmond?
Cumbria
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When did Storm Desmond occur?
December 2015
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How many homes were flooded during Storm Desmond?
5,200
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What was the highest amount of rainfall measured during Storm Desmond? (in a 24hr period)
On 5 Dec, Honister Pass recorded 341.4mm of rain in just 24hrs
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What was disrupted during Storm Desmond?
major roads and railways were disrupted for several days
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What was affected by a landslide during Storm Desmond?
a landslide closed a section of the West Coast Mainline between Preston and Carlisle
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How many homes lost power during Storm Desmond?
61,000- when an electrical substation was flooded
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What weather system caused Storm Desmond?
a deep Atlantic low-pressure system. Associated fronts stretched across Northern Britain, bringing prolonged and heavy rainfall through a mechanism know as a "warm conveyor"
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What was the "warm conveyor" that caused Storm Desmond?
a "conveyor" of warm and moist air reached the UK from the Caribbean, where sea temps were usually high. The air fell as relief rainfall over Cumbria over 48hrs.
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What previous weather made Storm Desmond even worse?
the ground was already saturated as Nov 2015 had been the second wettest Nov since 1910 (in Northwest England)
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How did the jet stream impact Storm Desmond?
The jet stream remained over northwest England longer than usual, bringing depression from across the Atlantic
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How did farming in Northwest England impact Storm Desmond?
farming in the area had lead to the overgrazing of sheep leading to deforestation
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How did dredged channels in Northwest England impact Storm Desmond?
straightened and dredged channels lead to faster run off, reduced stream lag times, and higher discharge peaks
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Why were Keswick's flood defences inadequate to deal with Storm Desmond?
Keswick's flood defences were built to allow the water to rise 5m (like it did in 2009), but in 2015 it rose to 5.9m
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Why was River Greta mismanaged?- resulting in the worsening of the effects of Storm Desmond in 2015?
4.4m of high reinforced glass panels were built on the wall never to River Greta, but there was no dredging of the gravel that has raised the river bed over the last decade- so river couldn't absorb flood waters
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How did Storm Desmond impact short term employment in Carlisle?
In Carlisle, the United Biscuits factory (the city's biggest employer, was closed for weeks
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How did Storm Desmond impact long term employment in Carlisle?
When the United Biscuits factory reopened it had a smaller workforce, and the Turkish owners were forced to consider it's future in the high risk area
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How does frequent flooding affect investment in Cumbria?
flooding repeating in 2005, 2009, and 2015 deters long term investment in the area
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How much did the flooding in Cumbria in 2005 cost?
£100 million
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How much did the flooding in Cumbria in 2009 cost?
£270 million
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How much did the flooding in Cumbria in 2015 cost?
£400-500 million
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How much was claimed as insurance because of flooding in the UK?
over £6 billion in 2015
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What did farmers lose due to Storm Desmond?
hedgerows and expensive dry stone walls were washed away and many sheep drowned
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How did Storm Desmond impact house prices in Cumbria?
they fell
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How many houses were flooded in Cumbria in 2005 (compared to 2015)?
3000 were flooded in 2005 and over 5200 in 2015
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How did Storm Desmond affect local mental health in Cumbria?
residents suffered anxiety, stress and psychological trauma
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What impact did Storm Desmond have on river banks?
they were eroded, adding to future flood risk
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How did Storm Desmond affect water quality in Cumbria?
rivers were choked with debris and contaminated with pollutants and sewage
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How did Storm Desmond impact ecosystems in Cumbria?
soil eroded, and habitats were destroyed. Th saturated ground lead to the decomposition of dead plants and animals giving off noxious gas such as hydrogen sulphide. Other poisons contaminated food chains
292
How strong was the El Nino in Dec 2015?
it was the strongest El Nino since 1950
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Which floods has the 2015 El Nino been linked to?
the worst floods seen in 50 years in Paraguay, Argentina, Uruguay, and Brazil
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How many people in South America were forced out of their homes by the floods caused by the 2015 El Nino?
over 150,000 people- over 100,000 of them in the Paraguayan capital alone
295
How many people died in the USA in 2015 due to the strong El Nino?
13 people died in Missouri from flooded rivers after tornadoes hit the region
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How did the strong El Nino in 2015 affect USA rivers?
an 8km section of the Mississippi river was closed to vessels
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How did the strong 2015 El Nino impact the Arctic?
Storm Frank was part of a weather system causing high temps in the Arctic- A weather buoy near the North Pole recorded temps just above zero which is unheard of for Dec
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How did the strong 2015 El Nino affect ski resorts in France?
A French ski resort airlifted 100tons of snow to their slopes
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How did the strong 2015 El Nino affect Italy?
calm and dry weather exacerbated pollution over Milan and Rome
300
How did the strong 2015 El Nino affect Mexico?
snow was seen in parts of the Sonoran desert for the first time in 33years, and 3 deaths have been blamed on the cold in the Sonora state
301
How thick is the greenhouse layer around the Earth naturally?
280ppm
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How thick is the greenhouse gas layer around the Earth now?
430ppm- 150ppm thicker than it was naturally because of CO2 emissions
303
What does the layer of greenhouse gases around the Earth do?
it reflects heat back to the Earth's surface making it 30 degrees warmer
304
What affect does climate change have on climatic events?
increased droughts and floods leading to mass migration
305
What affect will climate change have on rainfall and water availability?
it will cause a reduction in rainfall which will reduce rain fed agriculture and water stores
306
What affect will climate change have on snow and ice and water availability?
Rising temps will cause snow and ice to melt which may increase water supply in the short term but then lead to major shortages
307
What affect will climate change have on sea levels and water availability?
It will cause sea levels to rise which could lead to increased salinity of coastal aquifers
308
What affect will climate change have on evaporation and water availability?
It will increase evaporation leading to increased evaporation from surface water stores and depletion of surface water stores as more water is in the atmosphere
309
What affect will climate change have on groundwater stores?
They will be depleted, impacting agriculture, industry, and domestic water supplies
310
What affect will climate change have on El Nino, La Nina, and water availability?
more extreme El Nino and La Nina events so increased drought and floods meaning less water available
311
What is the enhanced greenhouse effect?
increasing greenhouse gas emission by humans results in increasing heat trapped in the atmosphere resulting in increasing average air temperature and sea surface temperature
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How does climate change cause increased flood risk?
increased air temp means increased evaporation so increased cloud cover, increased rain therefore increased flooding
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how does climate change cause increased drought?
increased temp means increase in intense high pressure systems, so decreased humidity and precipitation and therefore increased drought
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In what regions is climate change likely to cause increased flooding?
tropics and mid latitudes
315
In what regions is climate change likely to cause increased drought?
sub tropics
316
In what regions is precipitation likely to increase, due to climate change?
the tropics and high latitudes
317
In what regions is precipitation likely to decrease, due to climate change?
in regions that 10-40 degrees North and South of the equator
318
In what regions are the frequency and intensity of heat waves likely to increase, due to climate change?
Southern Europe and Southern Africa
319
In what regions is evaporation increasing, due to climate change?
in large areas of Asia and North America
320
In what regions is soil moisture likely to increase, due to climate change?
any regions where precipitation increases
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As climate change increases the frequency of hydrological extremes, what will be the impacts on the hydrological cycle?
more intense rainfall will increase run off rates and reduce infiltration
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In what regions is groundwater flow likely to change, due to climate change?
there is non definitive link between groundwater levels and climate change
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In what regions is permafrost likely to decrease, due to climate change?
due to higher temps in air and ocean, permafrost will decrease in northern areas
324
In what regions is snow cover likely to decrease, due to climate change?
in the northern hemisphere
325
What are be the impacts of reduced permafrost due to climate change?
the deepening of the active layer has an impact groundwater supplies and also releases methane from thaw lakes which leads to positive feedback accelerating change
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How has spring melt changed?
in the last 50 to 100 years, spring melt has occurred earlier, possibly accelerating in the last decade
327
How has climate change affected ice cover?
glaciers have retreated globally and downwasting has accelerated in most areas since the 1970s
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What is downwasting?
the thinning of a glacier due to the melting of ice
329
Which glaciers have shown the most rapid changes?
tropical high altitude glaciers such as in the Andes
330
How has climate change affected the oceans?
increasing temps and evaporation from the surface
| there is limited evidence that more cyclones are generated
331
In 2030-2039, which areas will be affected by drought (due to climate change)?
most areas of the world, apart from Northern areas above 50 degrees as well as central Africa, India, and Argentina
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In 2030-2039, which areas will be worst affected by drought (due to climate change)?
coastal areas around the Mediterranean, Central America, and the South America.
333
In 2030-2039, which are the most densely populated areas that will be affected by drought (due to climate change)?
densest populations affected in the USA, Eastern China, and Europe
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In the future, which areas will have decreased rates of flooding (due to climate change)?
Europe, Western Asia, as well as
