Tropical Cyclones

This Natural Hazard project is about Tropical Cyclones. The point of this project is to help give you a better understanding of Tropical
How a cyclone forms
Cyclones through an information kit. This kit will include cause, effect, and management stratergies. In this information kit will also be information on a specific Tropical Cyclone, Tropical Cyclone Dorris.

What is a tropical cyclone?
Tropical cyclones are a type of natural hazard found in Australia. A tropical cyclone is a low pressure system. The most well known features of tropical cyclones are strong, destructive winds and heavy, continuous rainfall which can lead to flooding. A tropical cyclone can reach wind speed of 63 km/h, when a severe tropical cyclcone can reach atleast 118 km/h.

What Causes a tropical cyclone?
Tropical Cyclones get their main energy from the warm oceans which usually has a surface temperature of above 25°C. This is usually neccisarry for tropical cyclones
to form. For cyclones to develop a lot of broad-scale wind regimes will need to persist for several days. If the tropical cyclone moves over a land or cooler waters, the cyclone may dissipate. Tropical cyclones may also weaken if they enter an unffavourable wind regime which disrupts the air flow of the cyclone.

What are the four stages of a tropical cyclone?
as they form over the oceans
Immature- the clouds collect and move with the winds that start rotating clockwise around a low pressure area. The winds then get stronger
Mature- the cyclone reaches its peak in destructive power

Dacaying- the power of the cyclone starts to decrease because its either moved into colder, less tropical waters or its travelling over land, The pattern or the eye goes and winds are less strong.

Map of Australia showing cyclones between the years 2000 to 2006.
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different coloured lines = different tropical cyclones


Tropical Cyclone Dorris
Tropical cyclone dorris started as a tropical depression in the Arafura Sea on the 12 March 1980. It slowly moved east and then on the third day the winds near the centre reached gale force winds and was named cyclone Dorris. By the time it had reached Arntham Land, the cyclone and strengthened greately. The cyclone also raced through mining areas causing cost damages of $150 000.
Cyclone Dorris lead to no deaths but to heavy rain over Arnham Land, without significant flooding.

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Social effects:
No people died from tropical cyclone Dorris and no people lost their houses.

Economic effects:
It cost the community roughly $500 000 to fix any damages.

Environmental effects:

Management stratergies:

Before a cyclone hits you will usually recieve an early warning, letting you know when a cyclone is roughly going to hit. This will give the town enough time to evacuate the area which will help minimise the death toll. If the area you live in is prone to cycclones, before the cyclone season you can prepare an emergency kit. It should contain: a portable radio,
a torch,
spare batteries,
first aid kit,
non-perishable food,
sturdy gloves,
waterproof bags,
essential medications
copies of important documents (eg insurance details, birth certificates, prescription refills) in sealable plastic bags.

Also, you can develop a evacuation plan and an emergency phone number list.
To prepare your house for a cyclone you can:
contact the council to see if your house has been built to cyclone standards
make sure your house insurance will cover any damage
check the condition of your roof
windows must be fitted with shutters or metal screens

  • Trim any overhanging branches above or around your house
    clear the gutters of leaves. ect

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