South Africa’s department of water and sanitation ushered in spring with a warning to citizens of the North West province to use water more sparingly.
To add impact to their message, the department said “South Africa is ranked amongst the 30 driest countries in the world hence we are urging everyone to take responsibility in water conservation to avoid future water crises”.
How is ‘driest’ measured?
Ratau said that “the degree to which countries are dry or the ranking thereof is done in terms of water scarcity or average rainfall per year”.
But South Africa does not rank among the top 30 countries in the world when average rainfall per year is compared.
The countries with the least annual rainfall in 2014 were Egypt (51 mm), Libya (56 mm) and Saudi Arabia (59 mm).
Africa Check tried to verify the source of the 495 mm figure listed by the Food and Agricultural Organization for South Africa but was unable to do so at the time of publication. However, it is in line with South Africa’s average annual rainfall of 509 mm between 1981 and 2010 as calculated by the South African Weather Service.
Lecturer in the environmental and geographical science department at the University of Cape Town, Dr Kevin Winter, told Africa Check that while average annual rainfall by country is used as a measure of dryness it is not the sole or best measure.
“Rainfall varies considerably across South Africa and it therefore cannot be the sole indicator on scarcity rankings,” he added.
Other variables like evaporation, the amount of water that reaches and flows through rivers (called “mean annual runoff”), water demand and spatial variations across the country should be considered too.
A survey of water stress – which estimates how much demand is placed on a country’s water supply – put South Africa 65th of 180 countries in 2013. (See box below.)
How useful are rankings anyway?
Manager of the water resources research portfolio at the Council for Scientific and Industrial Research in South Africa, Dr Marius Claassen, told Africa Check that while country rankings may help South Africans understand their position as compared to other countries, they are not “the final answer”.
“We need to cope with what we have, regardless of how much other people have,” Claassen said.
Because “rankings aside, South Africa does have significant regions of high water stress, and is very vulnerable to water risks”, Andrew Maddocks, communications officer at the World Resources Institute, told Africa Check.
Conclusion: SA not among world’s 30 driest countries
The claim that South Africa ranks amongst the 30 driest countries in the world is not supported by available data.
Annual rainfall data shows the country ranked 39th out of 182 countries in 2014. However, an expert told Africa Check that rainfall is only one component that needs to be looked at as it varies considerably across South Africa.
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