The world’s fourth-largest desert fills nearly all Arabia
The Arabian Desert covers about 2.33 million square kilometres across almost the whole peninsula—from Yemen to the Gulf and from Oman toward Jordan and Iraq—ranking fourth among Earth’s deserts. Red dunes, quicksand, and scant rain still support oryx, sand cats, and hardy lizards.
Most of Saudi Arabia lies inside it, with arms into Iraq, Jordan, Qatar, Abu Dhabi, Oman, and Yemen, plus Sinai and adjacent Egyptian desert in the ecoregion. Rain often hovers near 100 millimetres yearly. Hunting, overgrazing, off-road driving, and settlement have erased striped hyenas, jackals, and honey badgers from many districts while endemic plants cling on.
The Rub’ al-Khali sedimentary basin stretches southwest–northeast; above about 1,000 metres, rock gives way to sand seas whose southern tip crosses Yemen.
Its southern heart, the Empty Quarter, is the largest continuous body of sand anywhere, with dunes up to 250 metres high built mostly of quartz. The Ad-Dahna corridor links it to the An-Nafud in the north, while the Tuwaiq escarpment curves 800 kilometres through limestone cliffs and canyons. The climate is hot subtropical desert, much like the Sahara, of which Arabia's desert is really an extension, though only a few pockets are hyperarid. Summer highs near the Gulf can hit 48 °C, and sunshine typically totals around 3,400 hours a year.
The ecoregion holds about 900 plant species, yet the Empty Quarter supports just 37, one or two of them endemic. There are 102 native mammals, among them the Arabian oryx, Nubian ibex, Arabian wolf and caracal; Asiatic cheetahs and lions once lived here too. Only 4.37 per cent of the ecoregion is protected. Saudi reserves include Harrat al-Harrah, founded in 1987 on the Jordan and Iraq borders, and 'Uruq Bani Ma'arid, where oryx and sand gazelle were reintroduced in 1995. Riyadh, home to more than 7 million people, sits at the centre.
Source: Arabian Desert
