SANDY COASTS OF INTERIOR SEAS UNDER LEVEL RISE: ASSESSMENT OF FUTURE DEVELOPMENT

Abstract

Modern coastal zone is an open morpholithodynamics system characterized by a set of constant and variable parameters. Estimations of these parameters allows to assess the future development of the whole system. Constant parameters are geological and geomorphologic composition of the coast and its wind-wave mode. Variables are long-period fluctuations of water level due to eustatic variations, tectonic and glacio-isostatic movements. Prediction of the evolution of the coastal zone includes the assessment of the trends of the variable parameters of the morpholithodynamics system. In this study, the above problem is analyzed on the examples of south-eastern coast of the Baltic Sea and the Russian sector of the Caspian sea. The possible rise of the Baltic Sea level by 1.0–1.5 m by the end of the XXI century will result in the further destruction of sea coasts, flooding, waterlogging and salinization of coastal areas, which will lead to negative consequences for industrial, municipal and agricultural infrastructures. In the case of the Caspian Sea, the majority of its coasts regardless of the underwater slope has transformed into lagoons due to the sea level rise in recent decades. Coastal erosion will start only when the sea level reaches the 1929 yr stage from which the sea level drop started in the mid XX century. At this stage, a noticeable change of surface slope occurs. At the majority of Caspian coasts activation of coastal erosion will occur when the sea level rise above – 26 m a.s.l.