Tropical Cyclones Are we at risk?
Questions What is a tropical cyclone? What is a tropical cyclone? How does it threaten us? How does it threaten us? What parts of South Africa are threatened? What parts of South Africa are threatened? How can we minimise the risk? How can we minimise the risk?
What is a Tropical Cyclone? relatively small, intensely developed low pressure cell relatively small, intensely developed low pressure cell occur over warm oceans occur over warm oceans diameter can range between 200 and 2000 km diameter can range between 200 and 2000 km maximum wind speed exceeds 110 km/h maximum wind speed exceeds 110 km/h Torrential rain Torrential rain
How does it threaten us? Floods Floods –Damage to roads, bridges, buildings –Loss of farmland –Silting of dams and river flood plains
How does it threaten us? Wind damage Wind damage –Loss of crops –Damage to buildings and communications –Stormy seas
What parts of SA are threatened? Where do they come from? Where do they come from? How do they travel? How do they travel?
Conclusion – most storms miss us Few reach 25 S as mature storms Few reach 25 S as mature storms Few reach 50 Few reach 50
Past events in South Africa
Demoina and Imboa (1984) –Extensive flood damage in KZN
Eline (Feb 2000) Extensive flooding in Mozambique and Limpopo valley Extensive flooding in Mozambique and Limpopo valley
Hudah (2002) Serious floods in Mozambique Serious floods in Mozambique
Japhet (2003) –Flood disaster in Mozambique and Zimbabwe (2003)
How can we minimise risk? Monitor information from the weather bureau Monitor information from the weather bureau Look at weather satellite images Look at weather satellite images Avoid settling on northern coastal shores Avoid settling on northern coastal shores Don’t live on river banks in KwaZulu Natal Don’t live on river banks in KwaZulu Natal
Conclusion We are not at high risk in this country We are not at high risk in this country But we should have flood relief programmes in place in KwaZulu Natal But we should have flood relief programmes in place in KwaZulu Natal