Investigating the Influencing Factors in the Fluctuations of the Caspian Sea Water Level

Kahjough Najjari Hadi

Caspian Sea, level surface, precipitation, evaporation, temperature

The rapid fluctuations of the Caspian Sea water level play an important role in determining the level of erosion risks, adverse environmental consequences, destruction and drying of coastal areas, wetlands and coastal bays, and the loss of economic resources and the destruction of marine industries. The purpose of this research is to investigate the influencing factors on the level of the Caspian Sea and predict the changes in the level of the Caspian Sea in the next 10 years. In this research, using ECMWF data from 1992 to 2021, which includes the amount of precipitation on the Caspian Sea, the amount of evaporation from it, and the average temperature of the surface of the Caspian Sea, the influencing factors in the fluctuation of the water level of the Caspian Sea were investigated. Reliable library sources were used to determine the amount of river water entering the Caspian Sea. Caspian Sea fluctuations data from the Ports Organization and to predict the Caspian Sea water level in the next 10 years, the time series and the specialized package Forecast of R software were used. The results showed that the amount of precipitation over the Caspian Sea is decreasing, and on the other hand, the amount of evaporation over the Caspian Sea is increasing. The main cause of the increasing trend of evaporation from the Caspian Sea is the increasing trend of sea surface temperature, which shows an increase of about 1.1 degrees Celsius during 30 years. One of the main reasons for the decrease in rain could be the intensification of the eastern winds and the weakening of the western winds, as a result of which the effects of the North Atlantic Ocean on the Caspian Sea are reduced. The Volga river water discharge shows a decreasing trend, which is due to the decreasing trend of precipitation and the construction of dams on the way of the rivers towards the sea. The prediction of the water level of the Caspian Sea in the next 10 years shows a decrease of 10 cm in the sea level. As a general result, climate change causes a decrease in precipitation, an increase in temperature and an increase in evaporation, and finally a decrease in the level of the Caspian Sea, so that this process will continue for the next few years.