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
Sajur River join the Euphrates on Syrian soil – the other two being the Balikh and the Khabur. The Sājūr is also the only river in Syria that enters the Euphrates on its right bank; both the Balikh and the Khabur flow into the Euphrates on the left bank. The Sājūr drains a total area of . The Syrian part of the Sājūr basin – the Manbij Plain – has been particularly well-studied. This area is bounded on the north by the Syro–Turkish border and extends as far south as Manbij. To the west, the Manbij Plain is bordered by basalt outcrops;