Caspian Sea shrinks by area equivalent to Albania over decades

Russian scientists have presented the findings of a large-scale study into the shrinking surface area of the Caspian Sea, which has contracted by an area comparable to that of Albania over three decades.

According to the Scientific Russia portal, researchers used Landsat satellite data to construct updated hypsometric curves linking water levels to the size of the water surface, with the new data expected to improve estimates of sea-area losses, evaporation rates and forecasts for future declines in water levels, Caliber.Az reports.

The data showed that, since 1995, the Caspian Sea's water level has been falling at an average rate of around 10 centimetres per year.

By 2025, it had dropped by nearly three meters to minus 29.4 meters, falling below the previous historic low recorded in 1977.

Over the same period, the sea's surface area contracted by 28,644 square kilometres — equivalent to 7.4% of its 1996 area and roughly comparable to the size of Albania.

The study also covered the Kara Bogaz Gol Bay.

The decline has already produced significant consequences. The shallowing of the Volga-Caspian shipping canal and ports across the Caspian basin has complicated navigation, while the retreating shoreline is moving farther away from coastal settlements.

According to forecasts, the sea level could fall by an additional two to 21 meters by the end of the 21st century.

Researchers noted that accurate projections require precise calculations of the Caspian's water balance, which in turn depend on reliable estimates of the sea's surface area, a key variable in evaporation calculations.

The authors of the study pointed out that while a smaller surface area would normally be expected to slow evaporation and reduce the rate of decline, satellite altimetry data indicate the opposite trend.

Between 2020 and 2024, the rate of sea-level decline accelerated to 22.7 centimetres per year, compared with 8.16 centimetres annually during the 2005–2019 period.

According to the researchers, this suggests that year-to-year fluctuations in the water balance currently exert a stronger influence than morphometric factors.

By Bakhtiyar Abbasov