Abstract

The strengthening of anthropogenic pressure on the catchments of small and medium-sized rivers of the Central Black Earth region of Russia, associated with significant plowing and an increase in the number of livestock complexes, contributes to an increase in the concentrations of organic substances and nutrients in permanent watercourses. At the same time, the sources of their point discharges are absent. This indicates an increase in diffuse pollution of rivers as a result of erosion-hydrological processes in economically developed catchment areas. The case of the formation of catastrophic pollution of the upstream reaches of the Psel (Psyol) River, which led to the mass death of aquatic organisms at the 25 km section of the river, is discussed. It was found that the reason for this is a catastrophic decrease in waterborne oxygen concentrations, caused by a combination of various active water-erosion processes in the plowed catchment area, related to anomalous rainfall, temperature regime, and hydrodynamic characteristics of this section of the river channel. It is shown that in the absence of measures aimed at soil and water protection on the catchments of small rivers of the Central Black Earth regions, in certain weather-climatic conditions, the diffuse water pollution of watercourses may reach a catastrophic level.

中文翻译：

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流域侵蚀-水文过程影响下Psel河灾难性污染的水化学特征

摘要

俄罗斯中部黑土地区中小河流流域的人为压力加剧，与大量耕作和牲畜群数量增加有关，导致有机物质和营养物质的浓度增加在永久性水道中。同时，它们的点放电源不存在。这表明在经济发达的集水区，由于侵蚀水文过程，河流的弥散污染有所增加。讨论了 Psel (Psyol) 河上游形成灾难性污染，导致该河 25 公里段水生生物大量死亡的案例。研究发现，造成这种情况的原因是水性氧浓度的灾难性降低，由犁过的集水区各种活跃的水蚀过程共同引起，与该段河道的异常降雨、温度状况和水动力特征有关。研究表明，在中央黑土地区小河流流域缺乏水土保护措施的情况下，在某些天气气候条件下，河道的弥散水污染可能达到灾难性的程度。