Cyclones are large-scale weather systems, or storms, extending between 150 and 1 000 km in diameter. The tropical cyclones that strike the Indian Ocean coastline of Mozambique develop in the Southwest Indian Ocean Basin (Leira et al. 2002), a region responsible for approximately 10% of all tropical cyclones on earth.
The map below illustrates the frequency of cyclone incidence over a period of 75 years from 1925 to 2000, including the tracks of some of the more recent storms.
TROPICAL CYCLONE FREQUENCY IN SOUTHERN AFRICA. SOURCE: LEIRA ET AL. 2002
The table below shows the impacts of floods related to tropical cyclones from 1984 to 2000.
Table: Major tropical cyclones affecting the coastline of Mozambique between 1988 and 2000.
Domoina1984350 000109
Name
Year
People Affected
People Killed
Filao
1988
90 000
100
Nádia
1994
900 000
52
Bonita
1996
200 000
11
Lisette
1997
80 000
87
Eline
2000
650 000
700 killed by flooding
associated with year
2000 cyclones
Gloria
2000
650 000
Hudah
2000
11 000
Source: Leira et al 2002
Tropical Cyclones and Floods
Tropical Cyclones often result in floods. Floods are discussed in more detail in the Hydrology Chapter of the River Basin theme, but following are two examples of how cyclones resulted in severe floods in the Limpopo region.
Tropical Cyclone Demoina - 1984
This event resulted in significant loss of life (60 people died) and widespread damage to infrastructure and property. 600 mm of rain fell in 24 hours, resulting in widespread flooding that removed vast areas of topsoil and destroying roads, bridges and housing across the northeastern South Africa, southern Mozambique and Swaziland.
Tropical Cyclone Eline - 2000
High winds and torrential rains resulted in devastating floods and widespread damage to property and infrastructure all across the Limpopo River basin. Much of the lower Limpopo River valley was flooded, innudating agricultural land and displacing thousands of people.
