Why it's important to classify droughts correctly
Not all droughts are the same, explains Professor Mike Muller.
Muller, a visiting adjunct professor at the University of the Witwatersrand, has written an insightful piece on The Conversation.
He says it's important to make the distinction between a meteorological drought, an agricultural (or farming) drought and a hydrological drought.
In his article, he defines them as follows:
- A meteorological drought occurs when rainfall is less than average over a significant period, often a month.
- An agricultural drought occurs when a lack of rainfall leads to a decline in soil moisture affecting pastures and rain-fed crops.
- A hydrological drought occurs when a meteorological drought significantly reduces the availability of water resources in dams, rivers, lakes and underground.
This is what the Western Cape is currently experiencing, Muller says.
The fourth type of "drought", Muller says, is the kind that is caused by "unthinking human action" prevalent across SA.
We don't really understand our weather, our climate and how it affects our water supply very well.Mike Muller, Visiting adjunct professor - University of the Witwatersrand
People really need to think about what drought means, who it's affecting and what's causing it.Mike Muller, Visiting adjunct professor - University of the Witwatersrand
He says defining a drought correctly becomes vital when government officials declare drought or disaster emergencies and put in place disaster aid.
A drought's classification has implications for the kind of relief and aid that will be expected.
There has been a bit of debate in the agricultural community about what they can expect from government.Mike Muller, Visiting adjunct professor - University of the Witwatersrand
Listen to the discussion on Afternoon Drive with John Maytham: