Lake Urmia in northwest Iran was once the largest lake in the Middle East. By the autumn of 2023, most of the lake had turned into dry salt flats. Although it revived in 2020 due to unusual rainfall, historical trends show that the lake has been drying out since 1995, reducing its area by nearly 90%.
Lake Urmia is nearly dry after a few years of new influxes of water raising the lake's level. Lake Urmia in northwestern Iran nearly dried up in the fall of 2023 after a rapid increase in water volume a few years ago. The largest lake in the Middle East and one of the largest hypersaline lakes on Earth, Lake Urmia has been transformed to its greatest extent into a giant dry salt flat.
On September 7, 2023, the Land Remote Sensing Satellite 9 Land Imager-2 (OLI-2) captured this image of a dry lake bed (above). This is in stark contrast to the image from three years ago (below), taken by Landsat 8's OLI (Old Land Imager) on September 8, 2020, when water filled much of the basin and salt deposits were only visible around the lake's perimeter. Prior to the replenishment, precipitation was above average and fresh water poured into the basin, expanding the lake's water area. Since then, dry weather has brought water levels back down.
Satellite image of Lake Urmia taken by the Land Imager on Landsat 8 on September 6, 2020.
The long-term trend for Lake Urmia is to gradually dry up. In 1995, Lake Urmia reached its highest water level; over the next two decades, the lake level dropped by more than 7 meters (23 feet), reducing its surface area by approximately 90%. Successive droughts, water use for agriculture, and the construction of dams on lakes and rivers have all contributed to the reduction in lake area.
A shrinking Lake Urmia has implications for both ecology and human health. The lake, its islands and surrounding wetlands are valuable habitats and are recognized by UNESCO as a Biosphere Reserve, Ramsar Site and National Park. The area is a breeding ground for waterbirds such as flamingos, white pelicans and white-headed pochards, as well as a stopover for migratory species. However, due to low lake levels, the remaining lake water is becoming increasingly saline, resulting in reduced food sources for brine shrimp and other large animals.
The shrinking of the lake also increases the likelihood that dust from the exposed lake bed will be picked up by the wind, resulting in reduced air quality. Recent studies have linked low water levels in Lake Urmia to impacts on the respiratory health of local residents.
The relative impacts of climate, water use and dams on Lake Urmia water levels remain a subject of debate. The lake's water levels did recover during a 10-year restoration plan that began in 2013. However, the program's effectiveness has been difficult to determine as heavy rainfall also fell during this period. Some studies believe that climate factors are the main reason for lake recovery.
Image from NASA's Earth Observatory, taken by Lauren Dauphin using Landsat data from the U.S. Geological Survey.