Expedition of the R/V Professor Panov (April 2018): preliminary results of observations of extreme flooding in the Lower Don Region

During the period of 2002–2018, southern Russia was subjected to extreme weather conditions, which can be characterized as drought. The water content and volume of the Don, Kuban, and Volga rivers decreased, salinization of the Sea of Azov was observed, and saline (4–6‰) Azov water periodically flowed into the Don River delta. Analysis of the hydrological observation data for 2018 revealed an episode of extreme flooding in the Lower Don (below the Kochetov hydroelectric complex) associated with the 15-year shortage of water in the body of the Don. An outstanding example of a natural and manmade anomaly in 2018 was the discharge of a significant amount of water from the Tsimlyan reservoir in April–May. For example, the average daily discharge was 345m³/s on April 10, 1503 m³/s on April 28, and 1701 m³/s by May 6. As a result, the maximum wave of water abundance in the Don formed by the end of April–beginning of May 2018, and the water level reached values not observed in the Don for 15 years. The research in the Gulf of Taganrog showed considerable desalinization of its eastern part. The level of salinization in this region did not exceed 2‰, while in spring 2017, the average values of salinization around the port of Taganrog were over 6‰.