Water quality analysis in the rivers of the southeastern part of Kaliningrad oblast
Yu.A. SPIRIN1,2, S.I. ZOTOV3, V.S. TARAN3
1Patrice Lumumba Peoples’ Friendship University of Russia, Moscow, Russia
2Institute of Geography, Russian Academy of Sciences, Moscow, Russia
3Institute of Geography, Russian Academy of Sciences, Kaliningrad, Russia
Keywords: watercourse pollution dynamics, anthropogenic impact, Angrapa River basin, water quality, river pollution mapping
Abstract
The temporal and spatial variability of the pollution level in the watercourses of the Angrapa River basin was analyzed based on data collected using the established hydroecological monitoring system. A network of monitoring sites was organized along the Angrapa, Pissa, Krasnaya, and Russkaya watercourses, covering areas from the headwaters to the estuary zones. The exception was the Angrapa River, where the first monitoring station was located near the state border, downstream of the source. Seasonal hydrochemical and hydrological studies were carried out over two hydrological years (fall 2022 - summer 2024). Based on the laboratory analysis of samples, water pollution indices (WPI) and specific combinatorial indices of water pollution (SCIWP) were calculated, the values of which were then distributed to the corresponding sections of the watercourses. According to the SCIWP, the water quality in the Angrapa River basin in 2023-2024 corresponds to class 3b (very polluted). The highest pollution level was recorded in the Russkaya River (4,82; class 4a - dirty), the lowest one - in the Krasnaya River (2,88; class 3a - polluted). Deterioration of water quality is observed from source to mouth, from forested areas to agricultural and urbanized territories. According to the WPI, the most “polluted” season was autumn (average value - 5,53; class V - dirty), the least polluted one was winter (1,74; class III - moderately polluted). The main excesses of MPC were recorded for oil products (70 % of samples), iron (97 %), phosphates (35 %), ammonium (19 %), nitrites (22 %), BOD5 (60 %), COD (71 %) and dissolved oxygen (48 %). A comparative analysis revealed interannual fluctuations in water quality, but the spatial structure of pollution was relatively stable. In 2023-2024, the pollution level decreased by 20-30 % compared to 2022-2023, with the most significant differences observed between similar seasons, which is associated with changes in water content. Although the concentrations of pollutants decreased, their list and frequency of detection in samples remained unchanged.
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