Given its importance and in order to adequately reflect the specific conditions as well as its complex hydrology, the Inventory dedicates five chapters to this river system. The shared tributaries of the Euphrates River (Chap.2l and the major shared tributaries of the Tigris River (Chap. 4J are covered in more detail in two separate chapters in order to highlight the role of these rivers and draw attention to local water issues and transboundary impacts.