Lake Urmia Basin Drought Risk Management: A Trade-Off Between Environment and Agriculture

The increasing severity of drought worldwide and recent environmental efforts to restore wetlands have put more pressure on management of water resources.The Lake Urmia Basin is an excellent example of this; the lake has been shrinking for the last two decades, agricultural water demand is growing and frequent drought has affected the basin negatively. The present study is part of the Lake Urmia drought risk management (DRM) that suggests a drought warning system with measures to reduce agricultural water consumption and allocate a reasonable amount of water for the lake at each drought level. The approaches to reduce agricultural demand include reductions in cropped area and deficit irrigation; these have been accepted by stakeholders and are calculated by means of optimization models. Strategies to allocate water to Lake Urmia include full allocation of 3100 MCM yr(-1) (the new water allocation of the lake) or up to 65% partial allocation of this amount in accordance with the severity of drought. These policies were simulated for the agricultural and environmental sectors throughout the historical and generated time series for streamflow. The results of simulation show that the new water allocations put increasing pressure on the agricultural sector and the basin will remain under water scarcity for more than 50% of the time after applying the DRM. It is a unique way to save the lake, which will otherwise dry up within a decade. The methodology can be recommended to model components of similar drought plans which will benefit from its applicability and objectivity. Copyright (c) 2017 John Wiley & Sons, Ltd.