ТЕНДЕНЦИИ ИЗМЕНЧИВОСТИ ХИМИЧЕСКОГО СОСТАВА И СТЕПЕНИ ЗАГРЯЗНЕННОСТИ ВОДЫ РЕКИ КУБАНЬ

Abstract

Introduction. The paper explores the long-term spatial and temporal variability of the chemical composition and water quality in the Kuban River. Methods. To study the variability of the chemical composition of river water, we analyzed data from systematic observations over the concentrations of major ions, biogenic and organic substances, petroleum products and heavy metals from 2010 to 2017. To describe the variability of water quality, we used such indicators as water quality class, water pollution level, and characteristic pollutants. Results. It is shown that the spatial change in the chemical composition is uneven — a number of components in the water have low concentrations in the upper reaches, increasing in the lower part of the river. Others are characterized by high concentrations in the middle reaches, followed by a decrease towards the mouth. Over time, the change in the concentrations of chlorides, sulfates, organic substances and petroleum products increases. As for the content of nitrates, a slight decrease was detected in its variability. For the remaining chemicals, there were no clear trends. We established that in most cases the water in the Kuban River can be classified as polluted and very polluted (water quality class 3). We also found that the nature of river water pollution regarding a number of components is stable. Conclusion. In modern conditions of sharp climate changes and anthropogenic impact, the identified features of the chemical composition and trends in water quality variability of the Kuban River are of great practical importance and can be used in the development of environmentally sound recommendations for improving water quality and the state of water ecosystems in the river basin.