Title: Tropical Cyclones
1Tropical Cyclones
This presentation is to be viewed with the
storyboard (see Module 3 Activity 1 on the CD).
It demonstrates how planning can result in a
presentation that answers the unit question. You
can delete this text box.
http//earthobservatory.nasa.gov/Newsroom/NewImage
s/Images/seawifs_cyclone_dera.jpg
2Questions
- What is a tropical cyclone
- How does it threaten us
- What parts of South Africa are threatened
- How can we minimise the risk
3What is a Tropical Cyclone
- relatively small intensely developed low
pressure cell - occur over warm oceans
- diameter can range between 200 and 2000 km
- maximum wind speed exceeds 110 km/h
- Torrential rain
4How does it threaten us
- Floods
- Damage to roads bridges buildings
- Loss of farmland
- Silting of dams and river flood plains
http//www.whistler.com/buzzard/photoj5.html
5How does it threaten us
- Wind damage
- Loss of crops
- Damage to buildings and communications
- Stormy seas
http//coastalhazards.wcu.edu/StormDamage/Opal/opa
l1.jpg
6What parts of SA are threatened
- Where do they come from
- How do they travel
http//www.weathersa.co.za/wfacts/9902-3.GIF
7Conclusion most storms miss us
- Few reach 25 S as mature storms
- Few reach 50
http//www.dmc.co.zw/images/saison_cyc_2001_2002.g
if
8Past events in South Africa
9Demoina and Imboa (1984)
- Extensive flood damage in KZN
10Eline (Feb 2000)
- Extensive flooding in Mozambique and Limpopo
valley
http//news.bbc.co.uk/1/hi/world/africa/649873.stm
11Hudah (2002)
- Serious floods in Mozambique
http//www.reliefweb.int/mapc/afr_sth/cnt/moz/moz_
hudah.html
12Japhet (2003)
- Flood disaster in Mozambique and Zimbabwe
http//www.reliefweb.int/w/rwb.nsf/ (2003)
13How can we minimise risk
- Monitor information from the weather bureau
- Look at weather satellite images
- Avoid settling on northern coastal shores
- Dont live on river banks in KwaZulu Natal
14Conclusion
- We are not at high risk in this country
- But we should have flood relief programmes in
place in KwaZulu Natal
