Introduction: Lake Urmia, at the northwestern tip of Iran, is one of the largest permanent hyper saline lakes in the world and the largest lake in the Middle East. The lake is located between Eastern Azerbaijan and Western Azerbaijan, west of the southern portion of the similarly shaped Caspian Sea. It extends as much as 140km from north to south and is as wide as 85km from east to west during high water level periods. Because of being located in a dry and semi-dry region, this region doesn’t have suitable water resources comparing with global average water resources. Drought, climatic fluctuations, and shortage and disorder of rainfall cause many problems with regard to food and water for people who live in this region. Urmia lake is also one the most important and the largest aquatic ecosystems of Iran. The systemic and chain changes in the lake will lead to great effects on the climate and economic, social and hydrology conditions. Oscillations of the lake water levels and volume in recent years have attracted many opinions and created apprehensions.