Iraq's only outlet to the sea is a short stretch of coast on the northwestern end of the Persian Gulf, including the Shatt al Arab waterway. Basra and Umm Qasr are the main ports. Iraq is approximately coextensive with ancient Mesopotamia. The southwest, part of the Syrian Desert, supports a small population of nomadic shepherds. In the rest of the country, life centers on the great southeast-flowing rivers, the Tigris and the Euphrates, which come together in the Shatt al Arab at the head of the Persian Gulf. The marshy delta was largely drained in the early 1990s as part of a government program to control the Marsh Arabs, who had participated in the Shiite uprising against Saddam Hussein; the drying out of the marshes led to a dramatic increase in duststorms and sandstorms. Marsh restoration efforts began in 2003, and by 2006 roughly half the area had been restored. Between the two rivers are numerous wadis and water basins.
Very little rainfall occurs in Iraq except in the northeast, and agriculture mainly depends upon river water. The sandy soil and steady heat of the southeast enable a large date crop and much cotton to be produced. The rivers cause destructive floods, though they occur less often as a result of flood-control projects undertaken since the 1950s. Farther upstream, as the elevation increases, rainfall becomes sufficient to grow diversified crops, including grains and vegetables. In the mountainous north the economy shifts from agriculture to oil production, notably in the great fields near Mosul and Kirkuk.
Nearly 80% of the population of Iraq is Arabic-speaking, while over 95% is Muslim (Sunni and Shiite) in religion. There are about twice as many Shiites as Sunnis, the latter sect being more numerous throughout the majority of Arab countries. The hilly uplands of NE Iraq are primarily inhabited by Kurds, who are largely Sunni Muslims; other large minorities include Turkomans (Turks), Armenians, and Assyrians (Nestorian Christians). Most of the country's once large Jewish population emigrated to Israel in the early 1950s. As a result of the insurgent and sectarian fighting that occurred following the U.S. occupation of Iraq in 2003, an estimated 1.6 to 2 million Iraqis had left Iraq by the end of 2006, mainly to neighboring Jordan or Syria; a similar number had relocated within Iraq. Among those who have left are an estimated two thirds of Iraq's Christians.