Urmia Lake

Lake Urmia is located in northwestern Iran in the region of Azerbaijan. At present, this lake bears the name of Urmia, which is taken from the name of the city of Urmia, the capital of West Azerbaijan province. In the 1930s, during the reign of Reza Shah, this lake was named Rezaieh Lake in his honor. After the Islamic Revolution of Iran in 1978, the name of the lake was returned to its former name, Lake Urmia, which is called Ormo Gulu in Turkish. In ancient Persian, this lake is called Chichest, which means shining. In Latin, the lake is called Lacus Matianus. For the last five hundred years, the area around the lake has been inhabited by Iranians, including Azerbaijanis.
Lake Urmia is the largest inland lake in Iran and the second largest salt lake in the world. The water of this lake is very salty and mainly feeds from Zarrineh, Simineh, Gader, Baranduz, Shahr-e-Chay, Nazlu and Zola rivers. The catchment area of Lake Urmia is 51,876 square kilometers, which covers 3% of the total area of Iran. This basin with plains such as Tabriz, Urmia, Maragheh, Mahabad, Miandoab, Naqadeh, Salmas, Piranshahr, and Azarshahr plains is one of the valuable centers of agricultural and livestock activities in Iran. Lake Urmia is the largest permanent reservoir in West Asia, located in the northwest of the Iranian plateau.
Urmia Lake National Park, after Anzali Lagoon, is one of the most interesting natural habitats for animals in Iran. Currently, 27 species of mammals, 212 species of birds, 41 species of reptiles, 7 species of amphibians and 26 species of fish make up the wildlife of this lake. This ecosystem is internationally registered as a protected area by UNESCO. The Environment Organization of Iran has identified most parts of the lake as a national park. With more than one hundred small rocky islands, this lake is a place for migratory birds to stop, including flamingos, pelicans, ducklings, woodpeckers and Nowruz chickens.
The water of Lake Urmia is from the category of sodium chloride waters and the mud of Lake Urmia is a black paste and one of the chloride flowers that has therapeutic properties for diseases such as rheumatism and arthritis. Lake Urmia, one of the most important natural habitats in the region of Azerbaijan, which is also very suitable for water sports such as swimming, boating and water skiing, is on the verge of drying up. Of course, the beautiful lake of Urmia, after good and suitable rains in 2016, enjoyed a significant increase of 56 cm, which increased the activity of the lake Artemia and changed the color of the lake. This incident turned the blue color of the lake red and doubled its beauty.
Lake Urmia catchment area with an area of 52,000 square kilometers is located between the provinces of West, East Azerbaijan and Kurdistan. The area of this lake in the summer of 2015 is approximately six thousand square kilometers, which is among the twenty-fifth largest lakes in the world in terms of area and is shared between the provinces of West and East Azerbaijan. The lake is located in the middle of a closed catchment so that all surface and groundwater overflows from the surrounding areas to the lake. The special position of the basin in terms of geology, high evaporation rate and continuous accumulation of salts in it, has led to the transformation of the lake into an extremely saline lake. The lake is surrounded by a number of freshwater lagoons. The complex of these wetlands has created an important ecological area around the lake.
This catchment is located at an altitude of 1280 to 3600 meters above sea level, the lowest point of which is Lake Urmia and the surrounding vast plains. In terms of climatic conditions, this basin has cold winters and relatively mild summers. The average rainfall in the region is estimated at about 350 mm, with most of the rainfall occurring from autumn to mid-spring. In the summer months, there is little rainfall compared to other seasons. The average annual temperature varies between 6.5 and 13.5 degrees Celsius depending on the altitude. August and September are the hottest months and January and February are the coldest months of the year.
The average annual surface evaporation of the basin is estimated at 1500 mm and varies between 100 and 2100 mm depending on the conditions. The average annual evaporation from the lake surface is estimated between 900 and 1170 mm. The water required for the lake is supplied through 14 permanent rivers and a number of waterways and canals that flow seasonally or occasionally. The average annual inflow of water to the lake is estimated at 5300 million cubic meters, which varies between 760 to 15260 million cubic meters. Direct rainfall on the lake surface, along with the entry of groundwater flows can be considered as other sources of water supply to the lake. Due to the widespread withdrawal of groundwater, the share of groundwater in the lake’s nutrition has declined rapidly.
The water in the lake is extremely salty (the average salt concentration is more than 200 dS / m) and varies according to the conditions and seasons. The amount of soluble salt in it is twice that of the oceans. Because of this, no fish or mollusks live in it except species of crustaceans, and its water never freezes. Among the most important invertebrates in the lake, we can mention Artemia, which is a saltwater shrimp species and one of the native species of Lake Urmia. This species is the most important food source for many waterfowl such as flamingos. Fresh water that flows into the lake from rivers and floods plays an important role in improving the water quality of the lake. The body of the lake is relatively shallow (average depth 5.4 meters). The length of the lake varies from 130 to 145 km and its maximum width is 58 km. The rate of water level fluctuations in low and high water years is about 3 meters. According to studies conducted during the last decade, as long as the water level of the lake fluctuates with an area of more than 1274.1 meters above sea level, the lake will continue its normal ecological function to maintain biodiversity and produce Artemia.