The geography of Iraq is diverse and falls into five main regions: the desert (west of the Euphrates), Upper Mesopotamia (between the upper Tigris and Euphrates rivers), the northern highlands of Iraq, Lower Mesopotamia, and the alluvial plain extending from around Tikrit to the Persian Gulf.
The mountains in the northeast are an extension of the alpine system that runs eastward from the Balkans through southern Turkey, northern Iraq, Iran, and Afghanistan, eventually reaching the Himalayas in Pakistan. The desert lies in the southwest provinces along the borders with Saudi Arabia and Jordan and geographically belongs in the Arabian Peninsula.
Most geographers, including those of the Iraqi government, discuss the country's geography in terms of four main zones or regions: the desert in the west and southwest; the rolling upland between the upper Tigris and Euphrates rivers (in Arabic the Dijla and Furat, respectively); the highlands in the north and northeast; and the alluvial plain through which the Tigris and Euphrates flow.
Iraq's official statistical reports give the total land area as , whereas a United States Department of State publication gives the area as .
The uplands region, between the Tigris north of Hamrin Mountains and the Euphrates north of Hit, is known as Al Jazira (the island) and is part of a larger area that extends westward into Syria between the two rivers and into Turkey. Water in the area flows in deeply cut valleys, and irrigation is much more difficult than it is in the lower plain. The southwest areas of this zone are classified as desert or semi-desert. The northern parts, which include such places like the Nineveh Plains, Duhok, Zakho and Amedi, mainly consist of Mediterranean vegetation. The vegetation cyclically dries out and appear brown in the virtually arid summer and flourish in the wet winter.
An Alluvial plain begins north of Baghdad and extends to the Persian Gulf. Here the Tigris and Euphrates rivers lie above the level of the plain in many places, and the whole area is a river delta interlaced by the channels of the two rivers and by irrigation canals.