According to research conducted by the Hydro-Climate Extremes Lab (H-CEL) at the University of Ghent in Belgium, up to 30 percent of the rainfall deficit can be attributed to reproducing soil dryness.
That droughts are self-expanding is based on the theory that the earth’s surface plays a fundamental role in generating rain, by providing moisture to the atmosphere through evaporation.
To support their hypothesis, the scientists analyzed the 40 largest droughts in recent history and, for each event, tracked the air over the regions studied as the area of the drought expanded.
This analysis allowed them to calculate how much of the downwind rainfall deficits were caused by drought of the soils.
One of the study’s authors, Dominik Schumacher, stated that the lack of precipitation behaves in a similar way to forest fires.
“While fires spread downwind by igniting more and more fuel in their environment, droughts do so by reducing their own rainfall supply through the drying up of the earth’s surface,” he said.