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Tropical Cyclones. Are we at risk?. http://earthobservatory.nasa.gov/Newsroom/NewImages/Images/seawifs_cyclone_dera.jpg. Questions. What is a tropical cyclone? How does it threaten us? What parts of South Africa are threatened? How can we minimise the risk?. What is a Tropical Cyclone?.
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Tropical Cyclones Are we at risk? http://earthobservatory.nasa.gov/Newsroom/NewImages/Images/seawifs_cyclone_dera.jpg
Questions • What is a tropical cyclone? • How does it threaten us? • What parts of South Africa are threatened? • How can we minimise the risk?
What 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
How 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
How does it threaten us? • Wind damage • Loss of crops • Damage to buildings and communications • Stormy seas http://coastalhazards.wcu.edu/StormDamage/Opal/opal1.jpg
What parts of SA are threatened? • Where do they come from? • How do they travel? http://www.weathersa.co.za/wfacts/9902-3.GIF
Few reach 25 S as mature storms Few reach 50 Conclusion – most storms miss us http://www.dmc.co.zw/images/saison_cyc_2001_2002.gif
Demoina and Imboa (1984) • Extensive flood damage in KZN
Eline (Feb 2000) • Extensive flooding in Mozambique and Limpopo valley http://news.bbc.co.uk/1/hi/world/africa/649873.stm
Hudah (2002) • Serious floods in Mozambique http://www.reliefweb.int/mapc/afr_sth/cnt/moz/moz_hudah.html
Japhet (2003) • Flood disaster in Mozambique and Zimbabwe http://www.reliefweb.int/w/rwb.nsf/ (2003)
How can we minimise risk? • Monitor information from the weather bureau • Look at weather satellite images • Avoid settling on northern coastal shores • Don’t live on river banks in KwaZulu Natal
Conclusion • We are not at high risk in this country • But we should have flood relief programmes in place in KwaZulu Natal