Lake Oroumeih (also spelled as Lake Urmia) is a major water body in northwest Iran. At the present time it is the largest lake in the Middle East and the third largest salt water lake on the planet. It is 140 km long, 55 km wide, and as deep as 16 m. However, dams on feeder streams, expanded use of ground water in the region, and a decades long major drought have caused the lake to diminish. The result is a major change in the region's ecosystem and a significant change in the area's economy.
The increased salinity of the remaining water has led to an absence of fish and has destroyed habitat for migratory waterfowl. Traditional tourism and recreation no longer are factors for the small communities near the lake.
Landsat satellite data, acquired by the U.S. Geological Survey, illustrate the gradual change. Three Landsat scenes were used to cover the lake in each of the scenes. In 1985 the dark tone represents the lake when it was at near full capacity. The green tones represent vegetation (agricultural crops and forests). In the 2010 image mosaic, light blue tones represent shallow water and salt deposits along the lake edges. The expanded green tones indicate increased use of ground water and river diversion for irrigation.
United Nations environmental studies indicate the lake is now 60% of the size it was in the 1980s and, at the current rate, will be completely dry by the end of 2013.