The Cufra Oasis in the Sahara Desert in southeastern Libya is easy to identify from space. In the vast desert expanse of yellow sand seas surrounding it, this dark feature stands out. Its distinct shape almost resembles the stick-figure sketch of a dog. Closer inspection of this oasis reveals that it is made up of a number of individual circular plots, each of which is a crop-bearing field irrigated by a center-pivot irrigation system. As described in slide #7, this type of irrigation system is easily identified by its circular nature. In this desert environment, the water supplying each field is likely pumped from a deep aquifer that contains ancient (nonreplaceable) water.
Each field in this scene is approximately 1 kilometer in diameter. The fields are in various states of use: the darker fields are active, the lighter fields fallow (between crops), and the lightest fields abandoned. Numerous hexagonal features among the circles might be other types of agriculture (not center-pivot) or other land use. These are located below the north-south-trending airport in the left side of the scene.
September–October 1988, image STS-26-45-05.