DYANAMICS OF GORGAN BAY CHANNELS, VITAL CONNECTIONS TO THE CASPIAN SEA

The Caspian Sea is the largest closed sea in the world, with area of 360,000 Km2 and no significant tide, less than 10 cm. The Caspian Sea water level is about 27m below the open seas, with 0.4m yearly fluctuation and 3m during last century. Gorgan Inlet which is known as Gorgan Bay (GB) is located adjacent to the southeastern corner of the Caspian Sea (Figure 1-a). GB is 60km long, 10km wide and connected to the Caspian Sea through a relatively wide and very shallow channel. GB plays important roles in various aspects of its surrounding region hence it is a must to recognize its existing situation, monitor its changes, and to predict its behavior at different conditions. The main problem is that the average precipitation in the area is about 0.5 m/year while the average evaporation is around 1.5 m/year, therefore with no noticeable river discharge, GB is facing a decrease of 1 m/year, of course if it is not fed by the Caspian Sea through the above mentioned channel. GB with maximum depth of around 3m will disappear in only three years!