Forecasting the Effect of Decreasing Long Time Trend of Caspian Sea Water Level on the Life of Gorgan Bay

Gorgan Bay is a semi enclosed water body which currently has only a permanent connection with the Caspian Sea through mouth of Ashouradeh-Bandartorkaman. Decreasing trend of the Caspian Sea water level in past 19 years caused to adverse effects by land production in shallow coasts of Gorgan Bay and it is threatening that limited connection of Gorgan Bay with the Caspian Sea will cause disconnection totally. In this research, the effects of decreasing trend of the Caspian Sea water level on the connection status of Gorgan Bay were modeled under two scenarios of decreasing mean water level collections of the Caspian Sea. In first set of scenarios, the average of 5.2 cm and in set of second scenarios the average of 10.5 cm of decreasing water level in the Caspian Sea were used to topography position modeling in the Gorgan Bay. Under the first set of scenarios, the results of modeling show that, the connection of the Gorgan Bay with the Caspian Sea will be cut off permanently in Chapaghly area affected by decreasing in negative level in 27.6 meter in water year of 1410 – 1411. Under the second set of scenarios, the results of modeling show that the connection of the Gorgan Bay with the Caspian Sea will be cut off permanently in Chapaghly area affected by decreasing in negative level in 27.6 meter in water year of 1402 – 1403. Therefore it suggests that all the projects and the strategic programs of the government in southern coasts of the Caspian Sea including Gorgan Bay, engineering and operational program to be operated according to Amenagement Territoire scheme regarding to the approach of decreasing the level of the Caspian Sea and probable scenarios