A system dynamics model to quantify the impacts of restoration measures on the water-energy-food nexus in the Urmia lake Basin, Iran

Water scarcity exacerbated by growing demand has created environmental, social, and economic challenges in the Urmia Lake Basin (ULB), Iran. Tackling these requires an integrated approach. A System Dynamics Model is developed simulating the water-energy-food nexus in the ULB as a holistic multi-sectoral system to assess the impacts of proposed restoration measures. Climate change is considered, as are the effects of increasing irrigation efficiency, increasing return flows, water transfers, crop land retirement, and reviving a portion of the lake on natural resources and the socio-economic state of the basin. Lake level is sensitive to climate change. A holistic restoration approach could be effective in restoring the lake to an ecological level. However, in doing so, electricity demand in agriculture could grow. A 20% retirement of irrigated wheat to curb water demand, when coupled with a 20% increase in yield on 80% and 50% of irrigated and rain-fed fields respectively, will not reduce overall wheat production. The effectiveness of various measures depends on monitoring and enforcement, particularly in restricting growth in agricultural water consumption. While proposed measures look positive, they may have unexpected consequences including increasing energy demand for electric pumps. This work can inform holistic decisions for Urmia Lake restoration.