Tigris–Euphrates river system Tigris–Euphrates river system The Tigris and Euphrates, with their tributaries, form a major river system in Western Asia. From sources originating in eastern Turkey, they flow by/through Syria through Iraq into the Persian Gulf. The system is part of the Palearctic Tigris–Euphrates ecoregion, which includes Iraq and parts of Turkey, Syria, Iran, Saudi Arabia, Kuwait, and Jordan. From their sources and upper courses in the mountains of eastern Anatolia, the rivers descend through valleys and gorges to the uplands of Syria and northern Iraq and then to the alluvial plain of central Iraq. The rivers flow in a south-easterly direction
Euphrates on the fields. The salinity of Euphrates water in Iraq has increased as a result of upstream dam construction, leading to lower suitability as drinking water. The many dams and irrigation schemes, and the associated large-scale water abstraction, have also had a detrimental effect on the ecologically already fragile Mesopotamian Marshes and on freshwater fish habitats in Iraq. The inundation of large parts of the Euphrates valley, especially in Turkey and Syria, has led to the flooding of many archaeological sites and other places of cultural significance. Although concerted efforts have been made to record or save as much of