The Tigris River is one of two main rivers of ancient Mesopotamia, what is today modern Iraq. The name Mesopotamia means "the land between two rivers," although perhaps it ought to mean "the land between two rivers and a delta." It was the marshy lower ranges of the conjoined rivers that truly served as a cradle for the earliest elements of the Mesopotamian civilization, the Ubaid, in approximately 6500 BCE.
Of the two, the Tigris is the river to the east (towards Persia, or modern Iran) while the Euphrates lies to the west. The two rivers run more or less parallel for their entire length through the rolling hills of the region. In some cases, the rivers have a rich wide riparian habitat, in others they are confined by a deep valley such as the Tigris as it rolls through Mosul. Together with their tributaries, the Tigris-Euphrates served as the cradle for the latter urban civilizations that evolved in Mesopotamia: the Sumerians, Akkadians, Babylonians, and Assyrians. At its heyday in the urban periods, the river and its human-constructed hydraulic systems supported some 20 million inhabitants.
Geology and the Tigris
The Tigris is the second largest river in Western Asia, next to the Euphrates, and it originates near Lake Hazar in eastern Turkey at an elevation of 1,150 meters (3,770 feet). The Tigris is fed from snow which falls annually over the uplands of northern and eastern Turkey, Iraq, and Iran. Today the river forms the Turkish-Syrian border for a length of 32 kilometers (20 miles) before it crosses into Iraq. Only about 44 km (27 mi) of its length flows through Syria. It is fed by several tributaries, and the major ones are the Zab, Diyalah, and Kharun rivers.
The Tigris joins the Euphrates near the modern town of Qurna, where the two rivers and the river Kharkah create a massive delta and the river known as Shatt-al-Arab. This conjoined river flows into the Persian Gulf 190 km (118 mi) south of Qurna. The Tigris is 1,180 miles (1,900 km) in length. Irrigation through seven millennia has changed the course of the river.
Climate and Mesopotamia
There are steep differences between maximum and minimum monthly flows of the rivers, and the Tigris differences are the sharpest, nearly 80 fold over a period of a year. The annual precipitation in the Anatolian and Zagros highlands exceeds 1 meter (39 inches). That fact has been credited with influencing the Assyrian King Sennacherib to develop the world's first stone masonry water control systems, some 2,700 years ago.
Did the variable water flow of the Tigris and Euphrates rivers create the ideal environment for the growth of the Mesopotamian civilization? We can only speculate, but there is no doubt that some of the earliest urban societies blossomed there.
- Ancient Cities on the Tigris: Baghdad, Nineveh, Ctesiphon, Seleucia, Lagash, and Basra.
- Alternate Names: Idigna (Sumerian, meaning "running water"); Idiklat (Akkadian); Hiddekel (Hebrew); Dijlah (Arabic); Dicle (Turkish).
- Altinbilek D. 2004. Development and management of the Euphrates-Tigris basin. International Journal of Water Resources Development 20(1):15-33.