Аннотация:The formation of diffuse pollution in the catchment areas of rivers and water bodies mainly by surface overland flow is considered. It is shown that in comparison with the time of normal annual runoff calculations by K. P. Voskresensky (1962) the surface overland flow during the flood period decreased currently from 2 times in the northern forest-steppe of the Russian European part to more than 10 times in the southern part of the steppe zone, mainly due to changes in climatic conditions. If not for the reduction in the area of autumn ploughing, characterized by low surface overland flow, this reduction would be even greater. In addition to that the ground overland flow increased during the warm period of the year. Accordingly, the share of warm season in diffuse pollution of rivers and reservoirs increased largely due to contaminated slope groundwater inflow.
DOI: 10.15356/0373-2444-2016-1-131-146