Evaluation of renewable water resources of Urmia Lake Basin using GLEAM

Lake Urmia, located at northwestern of Iran, is the biggest internal lake of Iran and one of the most hyper saline lakes of the world. The area of its basin is 51876 km2 and consists of several rivers, which Zarrine Roud, Simine Roud and Aji Chay are the most important ones among them. In recent years, as a consequence of excessive water discharge from water resources, ambitious water projects and precipitation reduction, lake water level has been reduced.In this research, in order to evaluate basin’s water balance, different tools like GLEAM, lake water balance and Iran water resources management company’s research have been used. Based on achieved results from GLEAM, basin’s Natural Renewable Water (NRW) for year 1394-1395 have been 5780.59 MCM; this is while more than 83% of it has been used in agriculture. The estimated Available Water based on Iran Water Resources Management Company’s research have been 3% less and also calculated Available Water based on historical data 45% more than GLEAM’s resultAnother important note is that 1541.02 MCM of Unavailable Water (Potential Water) have been used by basin, in which, 421.4 MCM of it provided by reduction in lake’s water level and remaining 1119.62 MCM, have been provided by groundwater supplies, caused reduction in ground water level in the basin; this is while official statistics, released by Iran Water Resources Management Company (IWRMC), have reported this amount 2210.99 MCM for year 1389-1390.