By Simulating Gullies, Geographers Discover Ways to Tame Soil Erosion

(PhysOrg.com) -- Dead zones in critical waterways, accelerated loss of arable land and massive famines. They're all caused by the 24 billion tons of soil that are lost every year to erosion, a phenomenon that costs the world as much as $40 billion annually. But predicting where erosion occurs, and thus how to prevent it, is a serious challenge.