Anthropogenic and Natural Biogenic Pollution in the Urvan River: А Three-Year Study

Abstract

This study assesses the pollution of the Urvan River, a 52-kilometer-long non-glacial tributary of the Cherek River, one of the main watercourses in Kabardino-Balkaria. Results from three years of observations were compared to established standard concentration values, and the water quality in the middle and lower reaches of the river was determined. The concentrations of pollutants in the Urvan River were analyzed, with particular attention to biogenic compounds such as NO₂^‒, NO₃^‒, and NH₄⁺, using chemical analysis methods conducted in an accredited laboratory according to established guidelines. An interannual comparative analysis of pollutant levels from 2021 to 2023 identified the year with the highest levels of biogenic compounds, which significantly impacted the river’s ecological condition. A classification system for environmental quality classes of surface water was employed to assess year-round pollution by year and season. The findings show that the Urvan River remains consistently polluted throughout all phases of the hydrological cycle. The study also highlights distinctive features of the river’s ecosystem and variations in pollution levels during the research period.