Volga-Caspian Canal in the 18th Century: Historical and Geographical Reconstruction of a Shipping Route

The paper analyses the hydrological regime of the Volga River delta, predetermined by the interaction of the river and the Caspian Sea. Its connection with fluctuations of the Caspian Sea level in the area of the Volga River mouths is considered using the example of the functioning of the Yarkovsky mouth where the “Old Volga” fairway entered the Caspian Sea in the 18th century. Documents, notes of Russian and European navigators, maps and sailing directions of the 18-19th centuries, which present both existing and obsolete toponyms of islands, shoals, and channels of the Volga River delta, were analyzed to find the location of the mouth. The history of the mouth investigation and mapping, and its navigation conditions are considered, as well as the reasons for termination of its use.The influence of transgressive-regressive regime of the Caspian Sea on the restructuring of the hydrological network in the lower reaches of the Volga River delta has been found for the 18-19th centuries. The routes of the shipping Volga-Caspian Canal for the studied period have been reconstructed. The stages of a westward displacement of the main bed of the Volga River have been described. Heterogeneous movement of the surface part of the Volga delta under the decreasing sea level is considered for its western and eastern parts.