Tigris–Euphrates river system through the central plain and combine at Al-Qurnah to form the Shatt al-Arab and discharge into the Persian Gulf. The region has historical importance as part of the Fertile Crescent region, in which civilization is believed to have first emerged. The ecoregion is characterized by two large rivers, the Tigris and Euphrates. The rivers have several small tributaries which feed into the system from shallow freshwater lakes, swamps, and marshes, all surrounded by desert. The hydrology of these vast marshes is extremely important to the ecology of the entire upper Persian Gulf. Historically, the area is known as Mesopotamia. As
Euphrates has been of vital importance to those living along its course. With the construction of large hydropower stations, irrigation schemes, and pipelines capable of transporting water over large distances, many more people now depend on the river for basic amenities such as electricity and drinking water than in the past. Syria's Lake Assad is the most important source of drinking water for the city of Aleppo, to the west of the river valley. The lake also supports a modest state-operated fishing industry. Through a newly restored power line, the Haditha Dam in Iraq provides electricity to Baghdad. Euphrates The Euphrates