LAUSR

Unlike Lake Urmia, its two neighbor lakes with similar climate and size have experienced stabilized condition over the past decades. Actually, greater impact of anthropological activities, compared to climatological parameters, on hydrological and ecological systems of Lake Urmia has been stated in the literature. In this paper, the impact of a recently constructed causeway on this lake is studied using environmental impact assessment approach. This study evaluates different alternatives for future re-development plans and clearly proves the importance of preliminary environmental studies during the design development phase of infrastructure projects. The depth-averaged flow module of NASIR finite volume solver was utilized to simulate the horizontal flow patterns in Lake Urmia. Considering hydrological and meteorological parameters, different scenarios regarding location and number of causeway openings (current opening location, opening in the middle of causeway, and 2 openings) were compared to the condition before causeway construction. Discharge values of 21 streams, average monthly evaporation of 5.93 mm/day and average monthly precipitation of 0.4 m/day were considered as input data of the developed model. The simulation results showed that horizontal flow circulations occur mostly on the southern part of the lake and the causeway opening variations generally affect the form of these circulations. In the scenario with causeway and only one opening in the middle, flow circulations present the most comparability to the lake’s flow circulation pattern before causeway construction, whereas the scenario with 2 openings has the least similarities.