Regional Features of Seasonal Variability of Ion Flux in the Kuban River Basin

The regional features of seasonal variability of ion flux in the Kuban River basin for the period 1990-2020 in the context of climatic changes and anthropogenic impact are considered. The study was based on long-term hydrochemical and hydrological data of the state observation network of Roshydromet. Statistically significant ion flux trends were determined using the Kendall rank correlation coefficient. The method of normalized difference-integral curves was used to identify contrasting periods of ion flux. Differences between the selected periods were assessed using the non-parametric Mann-Whitney test. It is shown that the intra-annual variability of ion flux in the Kuban River basin is determined by the water runoff of rivers. The analysis of the long-term dynamics of ion flux made it possible to identify contrasting periods of flux of substances. In the sites Protoka - Slavyansk-on-Kuban, Protoka - Slobodka, Pshish - Khadyzhensk, Psekups - Goryachiy Klyuch, there was a statistically significant decrease in ionic flux. The seasonal values of ion flux calculated for the selected periods made it possible to trace its changes during the change of contrasting periods of long-term dynamics. It is shown that the direction of seasonal fluctuations in ion flux corresponded to long-term variability - there was a decrease in the flux of substances in all seasons of the year.