Increased Vegetation Boosts Rainfall in the Sahel, Researchers Find

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Droughts can grip the vast Sahel region of Africa for decades, dramatically altering the border where forest and savannahs give way to the Sahara Desert. Predicting those droughts is vital, but hard.

Droughts can grip the vast Sahel region of Africa for decades, dramatically altering the border where forest and savannahs give way to the Sahara Desert. Predicting those droughts is vital, but hard.

Trying to improve those predictions, University of Wisconsin–Madison climate scientists used data from satellites, rainfall gauges and other sources to test models of the link between rainfall and vegetation in the dry region. They found that more vegetation encourages more precipitation by drawing moisture out of the ground and recycling it into the atmosphere, where it can fall as rain again. The research can help refine climate models to improve their short- and long-term predictions for the Sahel and other regions.

UW–Madison climate scientist Michael Notaro’s group, along with collaborators at the Department of Energy’s Oak Ridge National Laboratory, published their findings Nov. 30 in Nature Communications.

“The Sahel has a lot of socioeconomic challenges and is very vulnerable to drought. Changes in climate have large impacts in this region in particular,” says Notaro, the associate director of the Nelson Institute for Environmental Studies’ Center for Climatic Research. “Global climate models generally have no clear consensus on how precipitation is going to change this century in the Sahel. One of our goals with this work was to understand which models are most reliable for this region.”

Read more at University of Wisconsin-Madison

Image: Herders on camelback moving cattle in Niger. Livestock is an important economic resource in much of the Sahel, but limitations on water and pasturage provide constant challenges to herders. (PHOTO: LEONARDO A. VILLALÓN)