Rising in the high mountains in eastern Turkey, the Tigris River touches the northeastern border of Syria and then flows across Iraq. It is 1,180 miles (1,900 kilometers) in length. At Al Qurnah, in southeastern Iraq, the Tigris joins the Euphrates River to form the Shatt Al ?Arab. This broad waterway, which for the last half of its length forms the border with Iran, empties into the Persian Gulf.
Physical features
In Turkey the Tigris flows swiftly in a narrow valley, with gorges and rapids marking its course. It is fed by a number of small tributaries and drains a wide area of the eastern part of the country. Much of the river valley immediately above the Iraqi city of Mosul is now a reservoir, contributing to a large irrigation project. Further on, the Tigris receives additional water from the Great Zab and the Little Zab, both of which arise in the Zagros Mountains.
Every year during spring, from about March to May, the snows on the mountains melt and feed the Zab rivers. These, in turn, deposit their excess water in the Tigris, which can lead to devastating floods. Bakhma Dam on the Great Zab and Dokan Dam on the Little Zab, however, have helped to control the rivers' flow.
As the Tigris reaches the village of Tikrit, the valley walls recede. For the rest of its course the river flows over a wide, gently rolling plain.
- Wild pigs roam in the marshland between the Tigris and Euphrates rivers in southern Iraq.
The landscape becomes flat when the Tigris reaches the city of Al Kut, 200 miles (320 kilometers) downstream from Baghdad. As it continues on its course, the river loses water to marshes on both sides. Irrigation canals, seepage, and evaporation further reduce its flow as it moves toward Al Qurnah, where it joins the Euphrates.
History and economy
The fertile land between the Tigris and Euphrates was the birthplace of the earliest known civilizations. The Greeks called the area Mesopotamia, meaning “Land Between the Rivers.”
Because the Tigris provided ample water for irrigation, several ancient cities were built along the river. The city of Assur, which gave its name to the empire of Assyria, stood on its banks, as did Nineveh, Assyria's capital. Many of the most important historical cities were originally ports on the Persian Gulf, but over the centuries the river has deposited additional land at its mouth so that the cities now lie far inland.
The Tigris has continued to be important in modern times because it provides water for irrigation in a region that receives little rainfall. The river also deposits vast quantities of silt along its lower course, making the surrounding land fertile. It has a deeper channel than the Euphrates, which allows for easier navigation and which gives the river great commercial value. The chief modern cities on the Tigris are Baghdad and Mosul, both in Iraq.