Shuttle photograph of an irrigation scheme at Jabal Tuwayq in Saudi Arabia. Water is tapped from deep fossil reserves and fed through large rotating booms hence irrigating crops which would otherwise die in this barren region. In an effort to approach self-sufficiency in food production the Saudi's instigated an expansion program of irrigated agriculture in the early 1980's. They relied on this method (called center-pivot) primarily but they also incorporated some canal irrigation projects. The Jabal Tuwayq is one of four center-pivot schemes which tap the aquifiers (deposits of porous rock which can be used as sources of water) within the Central Arabian Arch.