a desert in Africa (United Arab Republic of Egypt) in the northeastern Sahara between the Nile Valley and the Red Sea. In the south (22° N lat.) it becomes the Nubian Desert. Large sections of the Arabian Desert consist of pebbly, sandy, and calcareous plateaus (ham-mada), which gradually rise from the west to the east. On the east, along the shore of the Red Sea, rises the crystalline ridge Atbay (city of Shayb al-Banat, 2,184 m). In winter periodic rainfalls carried by the northeastern winds from the Red Sea fall on its eastern slopes. They cause violent but short runoffs in the usually dry valleys. The underground drainage, which is conserved for the entire year, supports a sparse xerophytic, herbaceous shrublike vegetation in the valleys and occasional trees—acacia, tamarisk, sycamore, date palm, and doom palm (in the south). The population, primarily nomadic, raises livestock (goats, sheep, and camels). Agriculture is found in the occasional oases. On the shores of the Red Sea crude oil production and phosphorite mining are found.