The Tigris is a member of the two great rivers the Mesopotamia and the Euphrates. It flows from the mountains of southeastern Turkey through Iraq. The Tigris unites with the Euphrates near Basra, and from this junction to the Persian Gulf the stream is known as the Shatt-al-Arab. The length of the river is 1,150 miles long. - http://answers.ask.com/Society/History/where_is_the_tigris_river_located
The Tigris is a channel river. It flows from the Dicle River in the Kurdistan region and joins the Euphrates at the northwest part of Basra. Its main tributaries are the Great Zab, Little Zab, Diyala, and Karkheh rivers.