The volume of water discharged into the lake by these rivers varies considerably during the year: during the spring the Talkheh River and Sīmīneh River may each discharge about 2,000 cubic feet (57 cubic m) per second, while the rate drops to only 130 or 60 cubic feet (3.7 or 1.7 cubic m) per second in the dry summer. This variation causes the lake itself to rise and fall, fluctuating by 2 to 3 feet (0.6 to 0.9 m). In addition to seasonal variations, there are also longer periods of fluctuations, lasting from 12 to 20 years, with water-level fluctuations of 6 to 9 feet (1.8 to 2.7 m). Because Lake Urmia’s waters have no outlet, they are highly saline. The lake is one-fourth as salty as the Dead Sea, with a salt content ranging from 8 to 11 percent in the spring to 26 or 28 percent in the late autumn. The main salts are chlorine, sodium, and sulfates.
