The Tigris is approximately 1,800 km (1,150 miles) long, rising in the Taurus Mountains of eastern Turkey and flowing in a generally southeasterly direction until it joins the Euphrates near Al Qurna in southern Iraq. The two rivers together form the Shatt al-Arab waterway, which empties into the Persian Gulf. The river is joined by many tributaries, including the Diyala and both the Upper and Lower Zab rivers.
Baghdad, the capital of Iraq, stands on the banks of the Tigris, while the port city of Basra straddles the Shatt al-Arab. In ancient times, many of the great cities of Mesopotamia stood on or near the river, drawing water from it to irrigate the civilization of the Sumerians. Notable Tigris-side cities included Nineveh, Ctesiphon and Seleucia, while the city of Lagash was irrigated by Tigris water delivered to it via a canal dug around 2400 BC. Saddam Hussein's hometown, Tikrit, is also located on the river and derives its name from it.
The Tigris has long been an important transport route in a largely desert country. It is navigable as far as Baghdad by shallow-draft vessels, but rafts are required for transport upstream to Mosul. River trade declined in importance during the 20th century as the Basra-Baghdad-Mosul railway and roads took over much of the freight traffic.
The river is heavily dammed in both Iraq and Turkey, in order to provide water for irrigating the arid and semi-desert regions bordering the river valley. Damming has also been important for averting floods in Iraq, to which the Tigris has historically been notoriously prone following snowmelt in the Turkish mountains around April. Recent Turkish damming of the river has been the subject of some controversy, both for its environmental effects within Turkey and its potential to reduce the flow of water downstream.
The Tigris has seen significant water quality improvement in Iraq since the Allied invasion of Iraq due to efforts of the United States of America in rehabilitating and expanding sewage treatment plants.
Photo: Encyclopaedia of the Orient