Investigation of Locating a New Communication Channel in the Gorgan Bay Cased on Water Exchange Time

By the continued trend of decreasing water level the only connecting way of the bay to the mother sea will be possible in the Chapaghli area in the future .Accordingly, finding a solution to link Gorgan Bay to the Caspian Sea through construction of a new channel can guarantee the survival of this ecosystem. This paper addresses water change status in the Gorgan Bay via new communication channels and dredging old channels under the scenarios of declining water levels. In this research, two modules from two dimensional Mike21 model including advection-dispersion and Hydrodynamic under water reducing level scenarios were coupled together. Galogah channel by having the exchange time of 106, 87, 70.5 and 71.5 days and Anzan channel by having the exchange time of 117, 108.6, 64.6 and 79.5 days at levels 27, 27.5, 28.5 and 29.5 meters respectively were the priority of research and implementation. The maximum length of the Galogah and Anzan channels in Gorgan Bay were calculated 2 and 2.7 km, respectively. The Ismailsai, Ashurada, and Khozini channels had the highest water exchange time and also had the greatest need for dredging at any considered decreasing level. In view of connecting the Anzan Canal to the deepest part of the Gorgan Bay and preventing future destructive ecological succession, it is recommended that the Canal be considered as the connecting channel of the Gorgan Bay with the Caspian Sea by the research community and authorities.