چكيده به لاتين
Lake Urmia is the largest water body in the country and the second largest saltwater lake in the world. It has many economic, social and cultural values besides environmental importance at national and international levels. The lake now faces a sharp decline in water levels and an increase in salinity levels. This situation has not only many deleterious effects on various issues such as environment, economic, society, and health around the lake but also significant impacts on global scales. One of the important factors in the reduction of Lake Urmia level is the poor management of water resources, which led to uncontrolled water withdrawal. Therefore, efforts to provide a model for reallocating water resources at the catchment area with the aim of restoring the lake level is an important step in helping decision makers and water resource managers in this basin. The main purpose of this study is to assess the possibility of dynamic rehabilitation of Lake Urmia’s water level by using the hedging approach implemented in water demands in the lake basin. In this regard, several basic steps have been taken to achieve the desired goal. In the first step, long-term synthetic series of monthly inflows of the major rivers of the basin are generated. To this end, considering the large size of the basin, the approach of this study is to generate synthetic time series of the total annual water entering to the lake by using of observations data, and then use disaggregation models to produce the monthly time series of each important river. In this process, Spatial and temporal dependencies between the observation series are preserved. The results of the analysis and evaluation of generated series have shown that the important statistical characteristics of observational data with a 90% confidence level are preserved in the generated data. As a result, their adequacy and accuracy of these data are confirmed. In the second step, the system of resources-consumption of Lake Urmia basin is simulated using WEAP model. Therefore, it is possible to assess the effects of the applying hedging approach on meeting the demands. In the third step, in order to reallocate water resources based on hedging and then assess its effect on water level of the lake, the hedging curves have been used, which previously developed by Erfanian (1391) for the Lake Urmia basin. The results show that in the absence of any plans to rehabilitate the lake, the critical conditions on the lake not only will not improve but also the lake will dry up. While, with applying hedging rules at the basin level, the expected water level of the lake has raised to ecological levels. Thus, the system's reliability (in order to achieve the desired water level) has increased.
