Diyala

Related Category: Middle Eastern Physical Geography

(dĭyă´lă, –´ə), river, c.275 mi (440 km) long, rising as the Sirvan River in NW Iran and flowing SW through the Zagros Mts. into E Iraq, where it enters the Tigris River S of Baghdad. The Diyala is unnavigable, but its valley is an important trade route between Iran and Iraq. A dam on the lower Diyala provides flood control and irrigates the area NE of Baghdad.