Tigris

Tigris

a river in SW Asia, rising in E Turkey and flowing southeast through Baghdad to the Euphrates in SE Iraq, forming the delta of the Shatt-al-Arab, which flows into the Persian Gulf: part of a canal and irrigation system as early as 2400 bc, with many ancient cities (including Nineveh) on its banks. Length: 1900 km (1180 miles)

Collins Discovery Encyclopedia, 1st edition © HarperCollins Publishers 2005

The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Tigris

 

a river in Turkey and Iraq, part of which flows along the border of these countries with Syria. The Tigris measures approximately 1,900 km in length and drains an area of 375,000 sq km. It originates in the eastern Taurus Mountains of eastern Turkey and flows across the Jazira Plateau and a considerable part of the Mesopotamian Lowland. Near the city of Al-Qurnah, Iraq, it joins the Euphrates River to form the Shatt al-Arab River, which empties into the Persian Gulf. The Tigris has four major tributaries, all on the left: the Great Zab, Little Zab, Diyala, and the Karkheh, which reaches the Tigris during high water.

The Tigris is fed by rain and snow. High water occurs in spring, and the maximum flow rate is in April. Catastrophic floods occur as the water of the Tigris and its tributaries rises on the Mesopotamian Lowland. As a defense against the floods, the Tigris’ channel is fortified for much of its course; some floodwater flows through a canal into Lake Thirthar, northwest of Baghdad and between the Tigris and Euphrates. Rising floodwater also endangers Baghdad. To relieve this danger, Soviet specialists in 1976 helped build the Thirthar-Euphrates Canal, which measures 37 km in length and is capable of diverting 1,100 cu m of water per sec. The Tigris reaches its maximum discharge in its middle course. The mean flow rate at Baghdad is 1,240 cu m per sec; the maximum flow rate is about 13,000 cu m per sec. In the lower course the discharge is less, since some water is used for irrigation and some flows into swamps near the river. An oasis extends along the river’s middle and lower courses.

The flow of the Tigris is regulated by dams located near the population centers of Summara, Samarra, and Al-Kut, all in Iraq. The river is navigable for vessels with a draft of up to 1.2 m as far as Baghdad, and during high water as far as Mosul. The cities of Diyarbakir in Turkey and Mosul, Baghdad, Al-Kut, and Al-Amarah in Iraq are situated on its banks.

The region between the Tigris and the Euphrates is one of the most ancient centers of civilization on earth.

REFERENCE

Muranov, A. P. Reki Evfrat i Tigr. Leningrad, 1959.

A. P. MURANOV

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.