2.2- Weather Hazards and drought case studies

Question 1

How do tropical cyclones form?

Answer 1

Tropical cyclones form in warm ocean areas (27*)

1) rising warm air causes thunderstorms which group together making a strong flow.
2) An area of very low pressure form at the centre of the storm (the eye- the calmest area)
3) the storms rotate,accelerating in and are forming a tropical cyclone.

Question 2

When in the year, do tropical cyclones form?

Answer 2

June-November in the northern tropics

November-April in southern tropics

Question 3

What are the tropical cyclone characteristics?

Answer 3

• very low pressure
• form a cylinder of rising, spiralling air surrounding an eye of descending,high pressure air
• cloud banks called the eye wall surround the eye
• often 400km wide and 10km high.

Question 4

What are 5 hazards associated with tropical cyclones?

Answer 4

• high winds
• intense rainfall
• coastal flooding
• landslides
• storm surges

Question 5

What does Arid mean?

Answer 5

In ARID areas, the Normal climate is dry because they normally have high pressure which leads to low precipitation.

Question 6

What are some factors of Arid environments?

Answer 6

• permanent low precipitation
• 10-250 mm a year (precipitation)
• high pressure conditions
• mostly located in the tropics

Question 7

What are some drought conditions?

Answer 7

• low precipitations
• (in U.K.) drought is 15 days without rain
• high pressure
• located anywhere gloabally

Question 8

What are the two natural causes of drought?

Answer 8

Meteorological and hydrological

Question 9

What does meteorological mean?

Answer 9

This is where an area receives less than average precipitation.

Question 10

What does hydrological mean?

Answer 10

This is where the hydrological cycle receives less rainfall than normal.

Question 11

What are 2 human causes of drought?

Answer 11

Deforestation- trees reduce evaporation, store water and add to atmospheric moisture.
Damn building- restricts the flow of water, which lowers water levels further down stream.

Question 12

How does global circulation make some areas more vulnerable to drought?

Answer 12

Where Hadley and Ferrel cells circulate, descending dry air means there’s little precipitation. If the rain doesn’t come in wet season, the area has drought conditions

Question 13

What are the main 3 reasons why droughts are hazardous?

Answer 13

• subsidence- (groundwater levels drop causing land to settle at lower level)
• contamination
• wild fires

Question 14

Which under-developed country suffered from severe drought in 2015?

Answer 14

Ethiopia

Question 15

What are the 3 main impacts on people from the California drought?

Answer 15

• risk to people’s lives and property
• loss of food income
• building damaged

Question 16

What are the 2 main environmental impacts from the California droughts?

Answer 16

• air pollution destroyed habitats and wildlife

* impact on wildlife (e.g rivers too low for salmon to breed)

Question 17

What are the 3 main impacts on people from the Ethiopian drought?

Answer 17

• death of livestock causes food crisis
• people eat less and become ill and malnourished
• girls have to walk further to get water so cannot go to school.

Question 18

What are the 3 main impacts on the environment from the Ethiopian drought?

Answer 18

• migration of wildlife
• loss of 200,000 hectares of forest each year due to forest fires
• extension of some animals e.g the Grevy Zebra.