Determination of water requirements of Lake Urmia, Iran

April 21, 2011 - 0:0

Lake Urmia is a salt lake in northwestern Iran. The lake is situated between the Iranian provinces of East Azerbaijan and West Azerbaijan. It is the largest lake in the Middle East and the third-largest salt water lake on the Earth.

The main manmade reason of the recent drought:
More than 40 dams have been built over 13 rivers that feed the lake and the recent draught, which started in 1999, has significantly decreased the annual amount of water the lake receives. This, in turn, has increased the salinity of its water which may lead to an ecological disaster in the region.
A very sensitive ecosystem:
This Lake is a thalassohaline ecosystem. It is an extremely simple ecological pyramid. This makes it a very sensitive ecosystem. This ecosystem has been facing various threats regarding the amount of water released from the associated basin.
To calculate the lake water requirement with an ecological approach, we identified three variables: ecology, water quality, and water quantity indices as environmental indicators.
The ecological index represented by Anemia urmiana is considered as an independent variable; while, the water quality index represented by concentration of NaCl, and the water quantity index represented by water elevation are regarded as dependent variables.
Lake Urmia requires annually 3086 MCM of inflow water:
The salinity threshold of 240 ppt (parts per thousand) is selected as the water quality requirement for Artemia urmiana. Finally, the aggregation of these variables shows that Lake Urmia requires annually 3086 MCM( million cubic meters )of inflow water to have a sustainable ecosystem.
(Source: and staff )