Dry season far from over
Drought has to be understood as a natural and social phenomenon
IS SOUTH Africa currently experiencing the worst drought in 23, 30 or 34 years? What caused it? And how will we know when it is officially over? Lebohang Mojapelo of NPO Africa Check answers some of the most frequently asked questions about the drought.
When does low rainfall become a drought?
Defining a drought is not that easy and depends on who you ask, the South African Weather Service explains on its website.
However, climate information manager for the weather service, Elsa de Jager, told Africa Check that if a specific area in South Africa receives less than 75 percent of its normal rainfall, they consider that area to be experiencing a meteorological drought.
De Jager added “it can be safely assumed that a shortfall of 20percent from normal rainfall will cause crop and water shortfalls in many regions, accompanied by social and economic hardship”.
Although South Africa’s average rainfall has been low, only certain areas of the country are experiencing a meteorological drought, media liaison officer for the Department of Water and Sanitation, Sputnik Ratau, said.
This is because South Africa has “different hydrological zones, meaning that whereas some parts may be experiencing severe drought, others may not”.
So far, five provinces have been declared drought disaster areas: Mpumalanga, Limpopo, KwaZulu-Natal, North West and the Free State. Some parts of the Eastern Cape, Northern Cape and Western Cape are severely affected by drought’s effects as well.
What caused the drought?
While drought is common to southern Africa, associate professor in the department of oceanography at UCT, Dr Mathieu Rouault, explained that the two main causes of the current drought are El Niño and climate change.
El Niño is a rise in oceanic temperatures in the South Pacific that affects weather patterns across the globe and results in a reduction in rainfall in southern Africa. Rouault and a colleague published a scientific study that showed that “eight out of 10 of the worst droughts in the past 100 years happened during El Niño”.
Also, the country’s overall weather patterns, according to Rouault, are also further impacted by global climate change, leading to abnormally high temperatures.
Did South Africa really receive the least rainfall in a century last year?
According to the South African Weather Service, South Africa received the lowest rainfall between January and December 2015 since the recording of rainfall began in 1904.
Since 1904, rainfall in all nine provinces has averaged 608mm a year, while last year South Africa received an average of 403mm (66 percent of the annual average). Previously, the lowest rainfall received in a year was in 1945 when South Africa received 437mm (72 percent).
Because drought is experienced as a continuous period of low rainfall, it is important to measure it accordingly.
De Jager said that “although the annual total rainfall for South Africa for the months of January to December 2015 was the lowest since 1904, the four-year period of 1930 to 1933 might still be the driest continuous period experienced in South Africa”. The average rainfall for those years was 519mm annually (85 percent).
It’s important to keep in mind that these averages were calculated for South Africa as a whole. Some areas could have been very dry while others were not. For example, the Eastern Cape has had above average rainfall between 2010 and last year, De Jager said, while the Free State has had below average rainfall since 2012 and has been declared a disaster area.
Is drought defined by lack of rainfall?
Meteorological drought in itself is not a disaster, the authors of Drought and Water Crises: Science Technology and Management Issues, Donald Wilhite and Margie Buchanan-Smith, wrote. “Whether it becomes a disaster depends on its impact on local people and the environment. Therefore, to understand drought we have to understand it as both a natural and social phenomenon.”
In addition to meteorological drought, there are three main types of drought: Agricultural drought is defined by a lack of soil water to support the growth of crops, caused by too little rainfall, whether it meets the requirement of a meteorological drought or not.
Hydrological drought is caused by the low availability of surface water, such as low water levels in dams, rivers, lakes and other reservoirs. This can be caused by a meteorological drought or high water use, for instance.
Socio-economic drought occurs when human activity is affected by any type of drought. This may be in the form of lack of water supply, grazing land or food.
Professor of agrometeorology at the University of KwaZulu-Natal, Michael Savage, said: “To determine these types of drought requires an intensive study using data for the whole of South Africa. I do not think anyone has undertaken such a study yet.”
How has the drought affected agriculture?
The head of the Agricultural Business Chamber, John Purchase, said the effects on agriculture can be seen in the Free State, KZN and North West “as summer crops, especially maize, could not be planted in many areas, or plantings were severely damaged by the drought and heat”.
Soya, sorghum, groundnuts and sunflower crops have also been affected, which has negatively impacted South Africa’s food security.
Purchase said while South Africa usually exported maize, “it is clear that South Africa will have to import roughly five to six million tons of maize (half white and half yellow) to meet its internal demand”.
He added that “livestock farmers also have no or little grazing and fodder for their livestock, while drinking water for animals is a problem in many areas in these provinces”. This would all result in an increase in food prices in South Africa over the next few months, Purchase predicted.
Is South Africa’s water supply threatened?
The director of water resource planning systems in the Department of Water and Sanitation, Dr Benson Mwaka, told Africa Check the drought has affected the whole country, “resulting in water shortages with associated socio-economic suffering – though not to the same degree”.
The KZN region has been hit the hardest in this regard, while the Eastern Cape has been affected the least, he said. The department’s media liaison officer, Ratau, added that areas with little or no water resource storage facilities were the worstaffected most by the drought.
Mwaka said the country’s water storage capacity was under pressure. South Africa’s dams were 55 percent full on January 11, although this was still some way off from the 35-year low point of 34 percent reached in November 1983.
Is this the worst drought SA has ever had?
Professor at the Wits Global Change and Sustainability Research Institute, Bob Scholes, explained that the current drought is “one of the biggest drought events in living memory”. However, he said the extent of the severity of the drought was difficult to measure because it was not over yet.
Similarly, Savage said more research needed to be done to definitively compare the severity of this drought with previous ones. It was, therefore, not possible to say yet whether this was the worst drought in 23, 30 or 34 years.
How will we know when the drought is over?
It is usually only after the fact that one can determine what kind of drought it was and when it has ended, Scholes said. He said data on rainfall and the effects of a drought usually took a long time to be collected and analysed. Therefore, knowing when a drought ended occurred some time after it was broken. “The drought is not over yet, guys,” Scholes said.