ИСТИНА

An urgent current problem is to re-estimate the renewable water resources (natural resources of subsurface and surface waters) of European Russia in the context of intense anthropogenic pressure and changing climate characteristics, which affect the formation of water balance elements in river basins. The main peculiarities of European Russia in view of the stated problem are the exceedingly diverse natural conditions and a high level of economic development of the territory. The input data for the analysis were materials of State Water Cadaster, as well as Russian and international hydrometric and climatic databases. The data also include materials collected for about 300 watersheds in European Russia, chosen as representative for space and time analysis of variations in the formation conditions and dynamics of water resources from 1935 to 2007. The comprehensive assessment of water resources included: • estimation and analysis of variations in the characteristics of the annual and seasonal runoff in rivers of European Russia for the recent 38 years (1970–2007) in comparison with a period of approximately the same duration (1935–1969); • analysis of the major factors of water resources variations; • estimation of spatiotemporal characteristics of current water resources and compiling a series of maps describing their distribution; • assessment of the extent and direction of variations in water regime and the shares of nourishment sources; • calculation of the specific water availability and the current load on water resources • prediction of possible changes in water resources during the forthcoming decade. Special attention was paid to the southern part European Russia, where water shortages were recently observed. The recent climate change has affected the volume of annual, seasonal and minimum river runoff. Changes in both the annual distribution of flow and the nourishment structure have occurred in the majority of studied sites, resulting in a considerable increase in the rate of natural runoff regulation.