Ad-Dahna Desert passages which can be several kilometers long. Local Bedouin have always known these caves and some were used as water supplies. They were first systematically studied in the 1981, and later explored and reported by the Saudi Geological Survey. Ad-Dahna Desert The ad-Dahna Desert is the central division of the Arabian Desert. It is a corridor of sandy terrain forming a bow-like shape that connects an-Nafud desert in the north to Rub' al-Khali desert in the south. Its length is more than 1,000 km siding Twaik Mountains from the east and does not exceed 80 km in width. It is
Simpson Desert decades occurred during 2009-2010, and has seen the Simpson Desert burst into life and colour. In early March 2010, Birdsville recorded more rain in 24 hours than is usual in a whole year. Rain inundated Queensland’s north-west and Gulf regions. In total, 17 million megalitres of water entered the State’s western river systems leading to Lake Eyre. In 2010, researchers uncovered the courses of ancient river systems under the desert. The Simpson Desert is also a large part of the World Wildlife Fund ecoregion of the same name which consists of the Channel Country and the Simpson Strzelecki Dunefields bioregions