3. Weather Hazards Flashcards
1
Q
How does air always move?
A
from high to low pressure - causes wind
2
Q
what is wind
A
large scale movements of air due to differences in air pressure
3
Q
Why is there air pressure on earth?
A
due to the uneveness of of the suns heat on the earth
4
Q
Does hot air rise or sink?
A
hot air rises and cool air sinks
5
Q
where are the rays from the sun most direct to the eart
A
at the equator
6
Q
What happens in a Hadley cell
A
- trade winds blow the air from the tropical regions to the equator
- air is heated due to the concentration of the suns rays at the equator and rises up
- air flows to high latitudes (30-40 degrees)
- here it becomes cooler and sinks over subtropucal regions, causing dry, cloudless air , and air warms as it descends
- this causes warm dry climates, such as deserts
7
Q
What happens in a Ferrel Cell?
A
- from 30-60 degrees North and South
- air sinks at the border of the Hadley cells and then goes east due to westerlies winds and rises at the border with polar cells as it gets warmer then goes west due to winds and becomes colder and sinks
- accounts for frequently unsettled weather, such as in the UK
8
Q
What happens in a polar cell?
A
- 60-90 degrees North and South
- air is cold here and sinks to form high pressure at the highest latitudes (90)
- cold air goes to border between ferrel cell and is slightly warmed before returning at altitude to the poles
9
Q
What is the Coriolis effect?
A
- the appearance that global winds and ocean currents curve as they move
- the curve is due to the earths rotation in its axis, which forces winds to move diagonally
- northeren hemisphere causes wind curves to thr ight, while in the south it is to the left
10
Q
What are prevailing winds?
A
- the direction the winds most frequently blow from (for UK it is south westerly)
11
Q
What are trade winds?
A
- prevailing winds that blow towards the equator on the left because of the coriolis effect
12
Q
What are westerlies?
A
prevailing winds between 30-60 N/S that blow from west to east due to the coriolis effect
13
Q
What are easterlies?
A
prevailing winds that blow from the east to the west between 60 - 90 N/S due to the coriolis effect
14
Q
What are the effects of climate change on tropical storms?
A
- global temperatures will rise due to climate change and global warming
- this means more of the world’s oceans will be above 27 degrees so more areas of the world will experience tropical storms
- oceans will stay at 27 degrees of higher for more of the year, so the frequency of storms will increase
- high temperatures mean storms will be stronger and more frequent
15
Q
What is a tropical storm?
A
- a huge storm that forms in the tropics
- called hurricanes, cyclones and typhoons
16
Q
What are the conditions for a tropical storm to form?
A
- the ocean needs to be at least 27oC
- Form in the summer and autumn when ocean temperatures are the highest
- Forms between 5 and 30 degrees North and South of the equator due to the equator not having the Coriolis Effect
- Unstable air (hot air rising rapidly) is needed
17
Q
How are tropical storms formed?
A
- The air is heated above the surface of a warm tropical ocean
- The hot air rises creating low pressure
- The hot air rising draws up more air and large volumes of evaporated moisture from the oceans
- The air will cool and condense to form large cumulonimbus clouds which generate large amounts of rainfall
- The heat given off when the water condenses powers the storm
- The Coriolis effect causes the air to spin upwards around the calm central eye of the storm
- The tropical storm travels across the ocean with prevailing winds
- When tropical storms reach land they are no longer powered by the moisture and heat of the ocean so lose power and weaken (also due to friction of land)
18
Q
What speed does a storm have to be to be tropical?
A
- 120Km/h
- 75 Mph
19
Q
What are the characteristics of tropical storms?
A
- 1-2 weeks
- heavy rainfall
- high wind speeds (over 119 kmh)
- high wave and storm surges
- strongest with lowest temperatures found within the eyewall
- measured by Saffir-Simpson scale
20
Q
What are primary effects of tropical storms?
A
- the immediate impacts of strong winds, high rainfall and storm surges
- secondary effects are impacts that occur after the storm has passed
21
Q
A
22
Q
What is some general infomation about Typhoon Haiyan?
A
- catgeory 5 storm
- 315km/hour winds
- sea temp of 30 degrees
- affected Samar, Leyte and Tacloban mostly
23
Q
What are the 5 main primary effects of typhoon Haiyan?
A
- 16 million people affected
- 13 billion total economic loss
- 1.1 million homes damaged or destroyed
- 4 million displaced
- 6201 people dead
24
Q
What are 3 social short term and 2 long term impacts of Typhoon Haiyan?
A
short term:
- 6201 people dead
- 1.1 million homes lost
- 28,626 casualties from lack of aid
long term:
- 21,000 families in 380 evacuation centres after 2 months waiting for bunkhouses
- influx of refugees into unaffected areas
25
What are 2 short term and 2 long term economic impacts of Typhoon Haiyan?
SHORT TERM:
- $13 billion
- 70,000 tonnes of sugar lost (85 million of farmland damaged)
LONG TERM:
- Tacloban City decimated
- debt cycle as foreign aid is needed and this comes at cost (20% of government revenue is to foreign debt)
26
what are 2 short term and 2 long term environmental impacts of Typhoon Haiyan?
SHORT TERM:
- coconut plantations flattened( coconut is Phillipines half agriculutural export)
- oil and sewage leaks
LONG TERM:
- 90% of rural population in typhoon affected areas are small scale farmers
- help from foreigners to mil the lumber of all the fallen trees
27
What were 3 short term responses to Typhoon Haiyan?
- Inernational aid agencies responded with food, water and temporary shelters
- the USA sent 13,000 soldiers
- 1200 evacuation centres for the homeless
28
What were 3 long term responses to Typhoon Haiyan?
- UN donated financial aid, supplies and medical support
- rebuilding of ports, airports, roads and bridges
- cash for work schemes gave locals money to help clear debris
29
In what 3 ways can a country be more vulnerable to tropical storms (with examples)
- physical - areas where tropical storms form most commonlu and hit more frequently
- economic - dveeloping countries have a lack of money so can be vulnerable
- social - poorer build quality building so more easily damaged
30
how can monitoring be used to reduce the impacts of tropical storms?
- weather charts,software and satellites are used to track development and appoach of a tropical storm in a HIC (national hurricane centre florida)
- LIC's have limited monitoring and communication
- allows for warnings and evacuation
31
how can planning reduce the impact of a tropical storm?
- governments can plan evac routes so people can get away quicker and safer
- injuries are reduced as people have been educated and trained on what to do
- reinforcing doors and windows can reduce flying debris
32
how can protection reduce the impact of a tropical storm?
- protection means buildings are less likely to be destroyed, so less people die from this
- sea walls and levees to protect against storm surges
- buildings can be reinforced to survive tropical storms
- means short term expenses, but long term saving as reduced rebuilding
33
What is the UK's weather like?
- has a mild seasonal climate
- hot and sunny weather from south/western europe
- winter cold weather from eastern europe
- arctic air brings snow and cold from the north
- air from the atlantic brings warm and wet weather
34
What is happening to the UK's weather?
- its becoming more extreme (informed by IPCC)
- global warming is increasing frequency and intensity of extreme weather events
- since 1980's extreme winter rainfall has increased
- more frequent gales, flooding, droughts, heatwaves, thick fog and snowfall
- temperatures are aslo more extreme (17,000 trains cancelled in 2014 due to freezing conditions)
- major flooding
35
What is some general info about the Somerste Levels?
- low lying farmland and wetlands bordered by bristol channels and Medip Hills
- drained by many rivers and people at risk due to floods
36
what caused the somerset levels floods?
- wettest juanry since records began in 1910
- high tides and storm surges swept water up rivers from bristol channel
- rivers had not been dregded for 20 years and were clogged with sediment
37
What were 2 social impacts of the somerset levels floods?
- 600 houses and 16 farms flooded/evacuated
- many people had power cut off
38
What were 2 economic impacts of the Somerset Levels Floods?
- damage of 10 million
- 14,000 hectares of agricultural land underwater for 2-3 weeks
39
what were 2 environmental impacts of somerset levels floods?
- floodwater was heavily contaminated with sewage and other pollutants
- huge amount of debris had to be cleared
40
What were the immediate responses to the somerset levels floods?
- villagers used boats to go shopping and go to school
- volunteers gave support
41
what were the long term responses to the somerset levels floods?
- 20 million flood action plan
- 8km of river tone and paratt were dredged to increase channel capacity
- river banks are being raised and strengthened and pumping stations are being made
