MAKHACHKALA, June 23 – RIA "Dagestan". The Southern Branch of P.P. Shirshov Institute of Oceanology of the Russian Academy of Sciences mounted a May expedition to study how the rapidly falling water level of the Caspian Sea affected the coastline in Dagestan. The field research took place under the Russian Science Foundation project "Development of Large Coastal Accumulative Forms of the Southern Tideless Seas of Russia under Changing Natural and Anthropogenic Factors" and was actively supported by Dagestanski State Nature Biosphere Reserve.
The scientists carried out a route survey of test sites within the Agrakhan Peninsula (the new delta of the Terek River and Chechen Island), in the area of the village of Novokayakent (the mouth area of the Artuzen River near Lake Papas) and in the delta region of the Samur River. As a result, up-to-date data were obtained on the morphometric characteristics of landforms, vegetation, the condition and composition of sediments of various origins as well as the course and consequences of extreme natural phenomena.
The field data still need to be processed and examined, but initial conclusions point to a contrasting picture. The exposed seabed of the channel that once separated the Agrakhan Peninsula from Chechen Island has become a meadow of flowering grasses. In the higher-lying areas, on the other hand, desertification advances—numerous plants disappear and previously stable dunes are on the move again.
Near river mouths, the drop in the erosion base has triggered a sharp increase in erosion, which has been made considerably worse by frequent and long-lasting floods. As an example, the cordon on the Terek River bank that served as the expedition's base has already been destroyed. This riverbank erosion, in turn, has delivered a massive volume of solid sediment to the coastal waters, causing the deltas to expand.
"We often underestimate the complexity of natural mechanisms. To this day, scientists still fiercely debate the causes behind the drop in sea level, while the sudden rise of the Caspian Sea at the end of the 20th century remains an even deeper mystery. Therefore, we are unable to predict a new rise, which could begin at any moment. Despite this uncertainty, there is a frantic rush to build across the entire coastal strip and adjacent dried lagoons, completely ignoring the potential consequences" - Marina Krylenko, the expedition curator and Head of the Laboratory for Lithodynamics and Geology at the Southern Branch of the IO RAS noted.