weather hazards ✓ Flashcards
how does atmospheric circulation cause tropical cyclones ?
- air moves around the world it moves away from the equator
- begins to rotate because of the need to disperse the high levels of heat at the equator across the earths surface
how do tropical cyclones form ?
- most commonly early autumn when sea temperatures are at highest
- air above warm ocean is heated
- when ocean reaches at least 27°C warm air rises quickly causing area of low pressure
- air continues to rise quickly it draws more warm moist air up from above the ocean leading to strong winds
- rapidly rising warm air spirals upwards due to Coriolis force
- warm air rises it cools and condenses forming large cumulonimbus clouds
- these clouds create eye wall and produce heavy rainfall
- centre of cyclone known as the eye is where cold air sinks forming the eye and in here the conditions are dry and calm
what are the characteristics of tropical cyclones ?
- form towards the end of summer and in the autumn
- feature strong winds, heavy rain and often thunderstorms
- average wind speed is 120 kph - 400 kph
- normally move east to west with the trade winds
- have an eye, calm centre of the storm
- have an eye wall which surrounds the eye it is a high density of cloud
where are tropical cyclones found ? why ?
found close to the equator because that is where the sea is the warmest
how do tropical cyclones cause high winds ?
air continues to rise quickly it draws more warm moist air up from above the ocean creating strong winds
how do tropical cyclones cause intense rainfall ?
warm air rises quickly and then cools and condenses forming cumulonimbus clouds which form the eye wall and produce heavy rainfall
how do tropical cyclones cause landslides ?
- saturate soil quickly
- can cause unstable slopes
how do tropical cyclones cause storm surges ?
- produce strong winds that push the water into shore
- can lead to flooding
- makes storm surges very dangerous for coastal regions.
how do tropical cyclones cause coastal flooding ?
combination of high winds, heavy wave action
what are the affects of storm surges ?
- erodes beaches
- erode coastal habitats
- damage coastal defences
- contaminate farmland
- contaminate fresh water
what are the affects of coastal flooding ?
- flooding
- risk of property, people, farming, tourism
- environmental flooding by salt water can be damaging
what are the affects of landslides ?
- risk people
- risk property
- risk local environment
- river flooding can be made if landslide blocks river channel
what is the movement of tropical cyclones ?
- do not remain where they are formed
- they follow the direction of the local prevailing winds
- the track of the tropical cyclone affects how strong it becomes when the cyclone is on dry land it loses its energy from its source the ocean
what were the social impacts of Hurricane Sandy on the USA ?
- 117 people were killed
- nine million homes had power cuts
- 650,000 homes were damaged or destroyed in the whole of the USA
- the streets of New York were flooded as was the subway
what were the economic impacts of Hurricane Sandy on the USA ?
- insurance claims in New Jersey totalled US$3.3
- Us$1.1 billion spent in repairing the damage to sewage and water people I New Jersey and New York
- damage cost in New York totalled US$19 billion
what were the environmental impacts of Hurricane Sandy on the USA ?
- the storm surge meant sea water got into fresh water habitats having severe impacts on the wildlife
- 1.5 billion litres of sewage was released into the Raritan River in New Jersey
- 90% of beaches in New York and New Jersey was damaged
- 1.5 millions litres of oil was spilt into Arthur Kill destroying wildlife habitats killing fish and birds
what were the social impacts of Hurricane Sandy on Cuba ?
- 11 people were killed
- there was no electricity or fresh water
- 17,000 homes were destroyed
- 226,000 homes were damaged
what were the economic impacts of Hurricane Sandy on Cuba ?
- total losses in Santiago area were US$50 million
- road to airport blocked so no tourists could come or go causing a loss in revenue
- US$2 billion in total losses
what were the environmental impacts of Hurricane Sandy on Cuba ?
- 2600 ha of banana crops were destroyed some of the crop was close to Maisi town
- in Santiago de Cuba trees were uprooted and lost all of their leaves
- coffee plantations in mountainous areas were swept away
- area close to the coast were flooded with beaches been swept away destroying wildlife habitats
how did individuals respond to Hurricane Sandy in USA ?
American people rebuilt their homes but used tradesmen rather than doing it themselves
how did organisations respond to Hurricane Sandy in USA ?
Red Cross had 17,000 trained worker 90% of them are volunteers who provided with other aid over 300 response vehicles 74,000 overnight stays and 17 million meals and snacks
how did the government respond to Hurricane Sandy in the USA ?
US government approved US$60.3 billion in aid to the victims of Hurricane Sandy
why did Hurricane Sandy have these impacts on the USA ?
more people died because more people live in the USA and more homes were destroyed because more people live there
why did Hurricane Sandy have these impacts on Cuba ?
less people died because less people live there and less homes were destroyed however more money within families will have been lost because of the loss of money from the plantations
how did the government respond to Hurricane Sandy in Cuba ?
local government officials compiled data from families about the damage they had suffered so that the government could send the appropriate help
why did the USA respond to Hurricane Sandy like this ?
because they had the money and resources to pay others to help them
why did Cuba respond to Hurricane Sandy like this ?
because they didn’t have the money and resources to pay others so they had to do more themselves
how good was the USA at responding to Hurricane Sandy ?
very good because they got a lot of help to people quickly and efficiently
how good was Cuba at responding to Hurricane Sandy ?
for a country with less money and resources they were quite good however it took longer for people to get their lives back to normal again
what are the characteristics of arid environments ?
- lack of moisture
- soil is dry
- air is dry
- yearly precipitation is very low
what are the characteristics of drought ?
reduction of precipitation for a long period of time
what are the meteorological causes of drought ?
- if an area receives less rainfall compared to its average then there is a natural shortage of available water
- climate change is already having an impact on these processes and in some parts of the world is leading to more frequent or more severe droughts
- slight changes in circulation patterns can cause the rainy season to fail or be delayed having a huge impact on crop harvests in the Sagel region in Africa which has periods of low precipitation and then a rainy season which provides most of the annual rainfall
what are the hydrological causes of drought ?
- if there is less rainfall than normal entering the hydrological system then reservoirs lakes and groundwater supplies will start to decrease
- as less water enters the soil because of lack of rain, surface water drops, leading to drought conditions
what are the human causes of drought ?
- dams HEP to places and a supply of water but places further downstream may suffer from drought as the river will be carrying less water
- deforestation, chopping down trees for fuel reduces the soils’ ability to hold water causes land to dry out, which can cause drought in that area
- agriculture
how does atmospheric circulation make some places vulnerable to drought ?
lack of water vapour in the atmosphere means there is less precipitation and more chance of drought
why are droughts hazardous ?
leads to water and food shortages and is likely to have a long-term environmental, economic and health impact on the population
what were the impacts on people of drought in California ?
- lead to wildfires → risk of peoples lives and property
- 542 000 acres of crop production was lost → loss of food and income
- costing California US$2.7 billion per year → less state money to spend on services for people
- increased extraction from groundwater → infrastructure and buildings damages → San Joaquin Valley
what were the impacts on the environment of drought in California ?
- water diverted so wetlands get less → impacts on environment and wildlife
- wild fires → environmental damage → air pollution destroys wildlife and habitats
what were the impacts of people of drought in Ethiopia ?
- death of livestock
- loss of crops
- people eat less and become weak so more vulnerable to disease
- girls have to walk further to get water so cannot go to school
- long grasses used for roofing cannot grow so homes are unprotected
what were the impacts on the environment of drought in Ethiopia ?
- loss of habitat for fish and wildlife
- increase in disease in wild animals due to reduced food and water supply
- migration of wildlife
- loss of 200 000 hectares of forest every year due to forest fires
- extinction of some species → Grevy zebra
- wind and water erosion of soil
how did individuals respond to drought in California ?
- famers encourages to use water-efficient irrigation → drip irrigation
- homeowners encouraged to check for water leaks
- protestors campaigned against companies selling bottles local water
how did organisations respond to drought in California ?
university of California research project for effectively managing ground water
how did governments respond to drought in California ?
- public education campaigns such as Save Our Water
- brought in state laws requiring a 25 per cent cut in water use in California
how did individuals respond to drought in Ethiopia ?
held large charity events like Live Aid which helped raise money and awareness
how did organisations respond to drought in Ethiopia ?
- aid of agencies such as Oxfam and UNICEF are helping people get water supplies
- education charities are trying to help people get jobs in urban areas
how did governments respond to drought in Ethiopia ?
overseas governments have given aid
how good was California’s respond to drought ?
it was very good because they bought in the law of decreasing water supplies
how good was Ethiopia’s respond to drought ?
was good because they were raising awareness
