关于这张图
STS062-151-220 (4-18 March 1994) --- Great numbers of circular, center-pivot irrigation plots appear in this west-looking view of the northern Saudi Arabia (center to lower left). So many plots now exist that the face of Saudi Arabia as seen from low earth orbit has changed. Until a few years ago, there were only a few scattered center-pivots. Now the entire swath of country between the shifting sands of the Ad Dahna Sand Sea (light colors center and right) and the almost soilless Nejd Plateau (left) has been darkened by thousands of these agricultural fields. The Nejd Plateau is a mass of…
