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 ýserious environmental consequences. It is expected that with the current trend, the lake will be ýcompletely dried out in a few years from now. This study attempts to assess the impacts of human ýactivities on water level fluctuations of Urmia Lake by developing a comprehensive hydrologic ýsimulation model. Model development and calibration was carefully accomplished by utilizing effective ýwater resources management components in the basin. An important contribution was accomplished by ýproperly estimating the agricultural water demand and consumption in the absence of measured data. ýResult of long-term simulation reveals that excessive water consumption by inefficient and expanding ýirrigated agriculture is the main reason for Urmia Lake shrinkage. It was found that main reservoirs are ýonly responsible for 23% of current situation. Whereas, 77% of the current crisis has been caused by ýmiscellaneous agricultural water withdrawals in the basin.ý