URMIA, LAKE OF, in north-western Persia, between 37° 1o' and 38° 20' N. and between 1o' and 46° E., which takes its name (Pers. Deryacheh i Urmia, Turk. Urmi gol) from the town of Urmia, situated near its western shore, but is also known as the Deryacheh i Shahi and Shahi gol. The limits of the lake vary much, the length (north to south) from 8o to 90 m., the width (east to west) from 3o to 45, being greater in the season of high water in spring when the snows melt.
The mean depth of the lake is i5 to 16 ft., and its greatest depth probably does not exceed 5o feet. The lake has in recent years exhibited extraordinary changes of level, either due to a move ment of the earth's crust or merely to an increase of rainfall as compared with evaporation. De Morgan gives an area of 4,000 and 6,000 sq.km. and 2,317 sq.m.) for low and high water respectively. In the south is a cluster of about so rocky islands, the largest of which, Koyun daghi, i.e., "Sheep-mountain," is 3
to 4 m. long and has a spring of sweet water near which a few peo ple graze their goats and sheep. All the other islands are un inhabited. The lake is about three-fifths as salt as the Dead sea— far too salt to permit of any life, except of lower organisms.
By the U.S.S.R. treaty with Persia, of 1921, the railway from Tabriz to Julfa and branch line from Sofian to Lake Urmia and all the properties pertaining to navigation on the lake—for merly a Russian concession—were gratuitously transferred to Persia. From the port of Sharaf-Khaneh on the eastern shore of the lake a fleet of motor boats of 2o-16o h.p. is operated in con junction with the railway. The service is weekly. The lake is also navigated by clumsy craft with round bows and flat sterns carrying enormous sails. (See URMIA.)