Numerical Simulation of Urmia Lake and Ajabshir Coastal Aquifer Interaction

Groundwater resources have been one of the main freshwater suppliers in arid and semi-arid areas such as Iran. Urmia Lake’s basin located in East-Azerbaijan province, Iran is one of the areas where a significant portion of the water needs is provided by groundwater. The present study considers the interaction of Urmia Lake and Ajabshir coastal aquifer. Hence, a three-dimensional, heterogeneous and anisotropic model has been developed using a numerical code of SUTRA. This model has been used after calibration and verification procedure. The effects of decreasing Urmia Lake level, increasing this level to the ecological level, and increase or decrease in the net recharge rate of the aquifer on discharge to the aquifer from the lake and vice versa have been assessed . The results have been shown that decreasing the level of the lake with 0.4 m/year rate, decreases the average aquifer level by 1.7 m over 10-years period while increasing the level of the lake to its ecological level increases the 0.75 m average level of the aquifer in 30-years. Also, 10% increase in net recharge rate, 1.8 m increase in the average water table during 30-years while 10% reduction in net recharge rate causes the reduction of 1.7 m in the average groundwater level.