Paleohydrology of the Manych Strait in the Khvalynian basin of the Caspian Sea during the Late Pleistocene

Abstract

The paper discusses controversial issues of the paleohydrology of the Manych Strait—a key element in the water exchange system between the Khvalynian basin of the Caspian Sea and the Neoeuxinian basin of the Black Sea during the Late Pleistocene. Special attention is paid to two parameters: the maximum level of the Khvalynian transgression and the height of the spillway threshold through the Manych depression. Geological-geomorphological analysis, digital terrain modelling, and hydraulic modelling in the HEC-RAS system allowed reconstructing scenarios of Caspian water discharge through the Manych valley. The modelling results indicate that the most probable maximum level of the Caspian Sea during the Early Khvalynian transgression was approximately 40 m a.s.l. with a spillway threshold at 31 m a.s.l. Hypothetical limits of the discharge capacity of the Manych Strait channel of the Khvalynian Caspian basin were also calculated. The results can be used in further research.