The acreage includes five aflaj irrigation systems and is representative of some 3,000 such systems still in use in Oman. The origins of this system of irrigation may date back to AD 500, but archaeological evidence suggests that irrigation systems existed in this extremely arid area as early as 2,500 BC. Using gravity, water is channelled from underground sources or springs to support agriculture and domestic use. Threatened by the falling level of the underground water table, the aflaj represent an exceptionally well-preserved form of land use. In desert regions, the additional spectral information supplied by satellite sensors is well suited to distinguish different types of rocks and geological formations. Irrigated areas such as the aflaj system in the centre of the image appear in shades of intense green in this particular combination of spectral channels.
The image was taken on 28 October 2000 by the satellite Landsat-7 / ETM+ and has a resolution of 30 metres. It covers an area of 60 by 120 kilometres.