Assessment of water-energy-food nexus in Urmia Lake Basin : towards integrated planning and decision making for basin management

Water scarcity exacerbated with growing demand for water by different sectors has created major environmental, social, and economic challenges for water governance in Urmia Lake Basin, Iran. Tackling this problem calls for an integrated approach that considers the basin as a system with several interconnected elements where any change in one of them will affect other parts as well. Water, Food, and Energy nexus is an approach that can be used to address the interconnection among sectors of a system and the complex mechanism of it. The main objective of this research is to evaluate the influence of the plausible scenarios on the social, environmental and economic sustainability of the Urmia Lake Basin. In this study, a System Dynamic Model was developed to simulate the interactions between different effective variables in water, food, and energy sectors, Urmia Lake and local socio-economic state of the basin. Then, the effect of a number of scenarios on Urmia Lake and the basin were assessed by developed SD model. Indeed, in these scenarios the effect of future meteorological data (precipitation and evaporation), increasing the irrigation efficiency, different ratios of the farmer collaboration, recharging different percentage of the return flow to the lake, buying different portion of agricultural water right for Urmia Lake, reviving only a portion of the lake surface area and the projected values of the domestic and industrial water demand, on the lake were analysed. The results show the changing trend of the lake level is highly sensitive to the plausible climate change scenario. Also, the results illustrate, all of the measures (even with the lowest ratio such as irrigation efficiency of 0.6 with only 30% of the farmers collaboration) being considered to conserve the water in favour of the Urmia Lake, were effective to stop the downward trend of the lake and turn it to upward trend. However, reaching the ecological level requires an action plan considering all of the mentioned measures approaching to decrease the agricultural water demand as much as possible. Furthermore, it is important to assign strict enforcement considering some restrictions such as no more expansion of the crops land area, no growth of abstraction from wells, no change from low water demand crops to the high water demand crops. To increase the net benefit of the agricultural sector and food security, improving the value of the crops water productivity and yields can be a better strategy in comparison to growing the crops land area. Finally, although changing the diesel pump instead of the electric pump provides a suitable condition to monitor the groundwater abstraction, the electricity demand of agricultural sector will be increased dramatically; thus, it is important to find some alternative sources of energy to fulfil this extra demand in the future. All in all, according to the high amount of uncertainty about climate, socio-economic and governmental framework changes, finding a rigid plan undertaking the lake level will reach to the ecological value during a specific period (as a criteria) seems to be a big challenge; but, the amount of water-conserving in the basin for the lake throughout considering and implementing a numbers of small scale but sustainable and effective solutions can be also considered as a practical indicator for assessment of the lake restoration plan