Physical Geography

Deserts, river plains, and high mountains are Iraq's chief physical features. The desert section, a part of the Syrian Desert, is a sand-and gravel-covered plateau in the west and southwest. To the east it descends to the largely alluvial plains of the Tigris and Euphrates rivers. Below Baghdad the land is low-lying, barely above sea level, and often marshy. Above Baghdad the two streams occupy individual basins and are separated by a desertlike upland called Al Jazira.

Northeastern Iraq, part of the region known as Kurdistan, is crossed by plateaus and mountains that are part of the high Zagros system lying mainly in Iran. Peaks rise 10,000 to 11,800 feet (3,000 to 3,600 m), but most are considerably lower.

Iraq's chief rivers are the Tigris, the Euphrates, and their combined outlet, the Shatt al Arab (River of the Arabs). The Euphrates has no permanent tributaries within Iraq, only temporary ones called wadis. Chief tributaries of the Tigris include the Great Zab, Little Zab, and Diyala. Numerous intermittent lakes, some of considerable size, form during the rainy season. Disastrous floods sometimes occur, especially with the melting of mountain snow in the spring. In southeastern Iraq is an area of marshlands. Government drainage programs implemented in the early 1990's have significantly reduced these marshlands.

Except for the relatively temperate Kurdistan highlands, Iraq has a tropical climate that ranks among the world's hottest and driest. During July and August daily temperatures usually rise above 100° F. (38° C.) and rarely fall below 70° to 80° F. (21° to 27° C.). Winters are normally mild, with temperatures averaging about 45° to 55° F. (7° to 13° C.) during January. They seldom drop below freezing.

Summers are always dry. November to April is the rainy season, generally with 12 to 20 inches (300 to 500 mm) of precipitation in the north and less than 5 inches (130 mm) in the south. The Kurdistan mountains receive more than 40 inches (1,000 mm).