Finding the Causes and Evaluating Their Impacts on Urmia Lake Crisis ‎Using a Comprehensive Water Resources Simulation Model

Urmia Lake in northwestern Iran has been facing critical water level shrinkage in recent years with serious environmental consequences. It is expected that with the current trend, the lake will be completely dried out in a few years from now. This study attempts to assess the impacts of human activities on water level fluctuations of Urmia Lake by developing a comprehensive hydrologic simulation model. Model development and calibration was carefully accomplished by utilizing effective water resources management components in the basin. An important contribution was accomplished by properly estimating the agricultural water demand and consumption in the absence of measured data. Result of long-term simulation reveals that excessive water consumption by inefficient and expanding irrigated agriculture is the main reason for Urmia Lake shrinkage. It was found that main reservoirs are only responsible for 23% of current situation. Whereas, 77% of the current crisis has been caused by miscellaneous agricultural water withdrawals in the basin.