The present level of external nutrient load and its separate parts on the Kuibyshev reservoir — the largest one on the Eurasian continent, was estimated. The mathematic model for calculating mean annual input of nitrogen and phosphorus from river drainage areas of non-homogeneous structure, and load on water bodies was developed. The main components of the load are the nonpoint nutrient emission by the underlying surface which is currently not affected by agricultural impact, the load generated by agricultural activity, discharges of pollutants from point sources into the hydrographic network of the catchment area and directly into the water-receiving reservoir, and the mass exchange with the atmosphere. The model includes calculating the retention of chemicals by catchments and by their hydrographic network. The model was calibrated against the data of State monitoring for the pilot areas: the catchment area of the Kazanka river (the left bank tributary) and the Sviyaga (the right bank tributary). The nutrient load generated by discharges from point sources of pollution was estimated using statistical reporting data. The values of atmospheric deposition of nitrogen and phosphorus on the surface of the study catchments were calculated using the data of field studies on the chemical composition of deposits. It is shown that implementation of the best available technologies into agricultural practice will not lead to any significant reduction in the nutrient load on the reservoir, because in recent years across most of the study area the rates of application of nutrients with organic and mineral fertilizers have been lower than the average removal of nitrogen and phosphorus with the harvested crops. An approximate estimation of nutrient load on the Kuibyshev reservoir was carried out for the left and the right bank sides of the catchment area. The background (natural) and diffuse (anthropogenic) components of the load are identified

中文翻译：

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从集水区估算古比雪夫水库养分负荷

估计了古比雪夫水库（欧亚大陆最大的水库）上的外部营养负荷及其独立部分的当前水平。建立了非均质结构河流流域年平均氮磷输入量和水体负荷的数学模型。负荷的主要组成部分是下垫面的非点养分排放，目前不受农业影响，农业活动产生的负荷，污染物从点源排放到集水区的水文网络并直接排入水中-接收水库，并与大气进行质量交换。该模型包括计算流域及其水文网络的化学品保留量。该模型根据试点地区的国家监测数据进行校准：Kazanka 河（左岸支流）和 Sviyaga（右岸支流）集水区。使用统计报告数据估计点污染源排放产生的养分负荷。利用沉积物化学成分的实地研究数据计算了研究流域表面氮和磷的大气沉积值。结果表明，在农业实践中实施最佳可用技术不会导致水库养分负荷的任何显着减少，因为近年来在大部分研究区域，有机肥和矿物肥料的养分施用率低于收获作物的氮和磷的平均去除率。对集水区左右岸边的古比雪夫水库养分负荷进行了近似估计。识别负载的背景（自然）和扩散（人为）分量