natural hazards - weather

Question 1

global atmospheric circulation

Answer 1

circular air movements called cells which join together to form the overall circulation of earth’s atmosphere
sinking air creates high pressure
rising air creates low pressure - ground winds moves towards low pressure areas
ground winds distorted by earth’s rotation
surface winds transfer heat and moisture
pressure belts and winds affected by seasonal changes - tilt and rotation, winds move north in summer, south in winter

Question 2

cloudy and wet weather in uk

Answer 2

uk is close to boundary of cold polar air moving down from north and warm tropical air moving up from south
boundary is unstable. rising air and low-pressure belts on ground - rising air cools , condenses and forms cloud and rain

Question 3

hot and dry weather in the desert

Answer 3

air is sinking, belt of high pressure, no rising air so few clouds and little rainfall, hot during day, cold at night as heat is lost quickly from ground

Question 4

hot and wet weather at the equator

Answer 4

rising air, low pressure belt, sun directly overhead so a lot hotter than UK, cloudy and high rainfall, humid

Question 5

where do tropical storms form

Answer 5

need warm oceans with temperatures over 27C so only over tropical oceans
summer and autumn when sea temperatures are highest
5-15 degrees north and south of equator - sufficient spin caused by earth’s rotation (coriolis effect), no spin at equator
unstable air in equatorial regions as intense heat so rises rapidly, condenses, forms storm clouds
trade winds responsible for mostly east to west storm paths - caused by air flowing over earth’s surface from sub-tropical high-pressure to equatorial low pressure belts

Question 6

how do tropical storms form

Answer 6

warm oceans, coriolis effect, unstable conditions in equatorial regions
rapid rates of evaporation transfers huge quantities of warm water vapor into air, rises rapidly, cools, condenses to form towering thunderstorm clouds, an eye is formed down the centre where air descends rapidly, most intense conditions at eye wall
storm carried by prevailing winds
loses energy source when it hits land, friction with land slows it down and it weakens

Question 7

structure and features of a tropical storm

Answer 7

eye - at the centre, column of rapidly sinking cool air, no clouds, calm
eye wall - most severe conditions, strong winds, torrential rainfall
cumulonimbus clouds - can reach heights of 15 okm
several bands of rain associated with clouds swirling
could have a diameter of 500km - large enough to cover england
move quite slowly - high rainfall, flooding, landslides

Question 8

affect of climate change on tropical storm distribution

Answer 8

more tropical storms originating in north atlantic and central pacific - change annually very small though - oceans becoming warmer
less storm in southern indian ocean and western north pacific - oceans and atmosphere warmed, reduces temperature range, more stable atmospheric conditions, formation less likely

Question 9

effect of climate change on tropical storm frequency

Answer 9

no obvious trend of an increase or decrease in frequency by there is expected to be an increase in number of intense storms

Question 10

effect of climate change on tropical storm intensity

Answer 10

increased due to to climate change - warmer moist rising air providing extra energy for formation
increasing sea surface temperature

Question 11

cyclone idai

Answer 11

14-15 march 2019
mozambique
africa’s deadliest tropical cyclone on record - category 2

Question 12

primary effects of cyclone idai

Answer 12

1300 killed - drowned, flying debris
90% of beira destroyed
heavy rains flooded agricultural fields and houses - no food or shelter

Question 13

secondary effects of cyclone idai

Answer 13

dams collapsed, two hydro-electric power plants damages
400 cases of cholera in beira - lack of sanitation and clean water
several rivers overflowed - washed away roads and bridges

Question 14

immediate responses to cyclone idai

Answer 14

over 140 evacuation centres set up in mozambique to cope with displaced people
UN dropped food and volunteers
uk governments provided £18 million of aid in form of food, water and shelter kits

Question 15

long term responses to cyclone idai

Answer 15

water supplies restored in beira
improvements to early warning system to increase awareness and preparedness
£2 million towards supporting families and communities rebuild lives

Question 16

monitoring and predicting tropical storms

Answer 16

satellites, radar, weather charts
hurricane watch - hurricane conditions possible, wide area
hurricane warning - hurricane conditions expected, take immediate action, specific area
predicted track of cyclone idai quite accurate - poor communication systems

Question 17

protection from tropical storms

Answer 17

cyclone shelters - on stilts, raised ground, multipurpose, strong concrete, window shutters, stairs to first floor safety
sea walls built to protect from storm surges
windows doors roofs reinforces - strengthen

Question 18

planning for tropical storms

Answer 18

raising awareness, national hurricane preparedness week in USA, families should devise action plan, hurricane evacuation routes

Question 19

uk weather hazards

Answer 19

thunderstorms - august 2020, electrical storms, 35000 lightning strikes
prolonged rainfall - lead to river floods, common
drough and extreme heat - rivers dry up, affects water supply, dangerous to elderly, over 20000 people died in 2003 in europe
heavy snow - less common can cause difficulty
strong winds - remnants of hurricanes, disruption to power, fallen trees

Question 20

why is there extreme weather in uk

Answer 20

meeting point of several types of weather from different directions - explains varied weather, occasional extreme weather

Question 21

evidence for extreme weather in uk

Answer 21

floods in 2007 - people died, homeless, hull, gloucestershire
heavy snow in 2010 - december, record -18.7 degrees C in northern ireland
strong winds in 2017 - power cuts, transport disruption, ireland, west britain
heat in 2019 - highest temperature in cambridge
(38.7 degrees C) in july

Question 22

2014 somerset levels floods

Answer 22

wetlands, drained by several rivers, developed for farming and settlements - at risk of severe flooding

Question 23

cause of somerset floods

Answer 23

wettest january on record - 350mm in jan and feb, 100mm above average
high tides and storm surges - from bristol channel, fresh water spilled over banks
rivers not dredged - at least 20 years, clogged

Question 24

social effects of somerset floods

Answer 24

over 600 houses flooded
16 farms evacuated
power supplies cut off for many

Question 25

economic effects of somerset floods

Answer 25

over 1000 livestock evacuated
80 roads closed - £15m cost to local economy
bristol –> taunton railway closed at bridgwater

Question 26

environmental effects of somerset floods

Answer 26

huge amount debris needed to be cleared
stagnant water had to be reoxygenated before put back into rivers
floodwaters heavily contaminated with sewage, oil and chemicals

Question 27

immediate responses to somerset floods

Answer 27

used boats to go shopping or attend school, community groups and volunteers gave support

Question 28

long term responses to somerset floods

Answer 28

rivers tone and parrett dredged - dredged annually
new flood alleviation schemes constructed at westonzoyland and aller
river banks repaired and raised to increase channel capacity