Development of SWAT-LU Model for Simulation of Urmia Lake Water Level Decrease and Assessment of the Proposed Actions for its Restoration;Part 3: Water Accounting Analysis and Assessment of the Proposed Actions for Restoration of Urmia Lake

The rapid drying rate of the Urmia Lake over the past two decades has caused great concern. Meanwhile, a number of measures are proposed for restoration of the Lake, which are also costly and need considerable investments. However, there have not been paid enough attention to analyse how, to what extent and under what circumstances; they can be effective. This paper attempts to address this issue and apply the developed integrated model (i.e. SWAT-LU) and link it to the water accounting framework (WA+) for more accurate evaluation of such measures to save water in the basin and increase inflows to Urmia Lake. To this end, the changes of water budget components under different restoration measures were evaluated in the form of water accounting reports. Moreover, the side effects of them were examined. The results showed that in spite of huge costs of some the measures (e.g. pressurized irrigation systems), they have not much positive effects in real water savings at the basin scale, and may even cause new problems in this regard. These results highlight the importance of considering scale for sustainable planning. It warns that results at the farm level are not supposed to be the same at basin scale.