Analysis of the Spatio-Temporal Dynamics of River Pollution in the South-Eastern Part of the Kaliningrad Region

Abstract

The purpose is to identify spatial diff erentiation (at 4 monitoring points in each river) and temporal variabil ity (by hydrological seasons) of chemical pollution and water quality in the Angrapa, Pissa, Russkaya and Krasnaya rivers. Materials and methods. The geographical location and coordinates of 4 monitoring points were determined. The water courses studies were carried out during 3 hydrological seasons (2022-2023): autumn low water (15.10.2022), winter fl ood (15.01.2023), spring fl ood (23.04.2023). A chemical analysis of water samples for a basic list of indicators was carried out. The current fi shery standard was used as the maximum permissible concentrations (MPC). The multiples of MPC excess of hydrochemical indicators and the water pollution index (WPI) were calculated for hydrological seasons. The boundaries of the catchment areas of the studied rivers were constructed on the basis of SRTM images in the SAGA GIS software pack age using standard built-in tools. Results and discussion. The dynamics of MPC multiples of the main pollutants recorded during 3 seasons and their potential sources were determined. After that, the spatial-temporal diff erentiation of WPI and its dynamics in the Angrapa River basin for 2022-2023 was constructed. The interseasonal variability of water quality in the river network and the factors aff ecting it were analyzed. Conclusion. During the study, the main pollutants and their consequences in the Angrapa River basin were identifi ed: dissolved oxygen, COD, BOD5, nitrites, ammonium, sulfates, iron and oil products. The increase in pollutants mainly occurs from the source to the mouth. The interseasonal dynamics showed an improvement in water quality from autumn to winter, and a deterioration from winter to spring. The main potential sources of pollution of the river network were iden tifi ed: agricultural activities, natural cycles of water and coastal activity, urbanized areas and groundwater. Water content also plays an important role in the processes of seasonal variability of water quality.