Contribution of Climatic and Anthropogenic Factors to Changes in the Flow of Large Rivers of the Russian Plain and Siberia

Resumo

Changes in the annual and seasonal flow of the Volga, Don, Yenisei, and Lena rivers were estimated by two independent methods. One of them is based on the data of water management statistics. The other method is based on reconstruction of the natural flow over recent decades, during which the flow experienced significant anthropogenic changes. The naturalized flow is subsequently compared with the real-time (anthropogenically modified) flow for this period and for the preceding base period, when the anthropogenic impact can be neglected. It was shown that climatic and anthropogenic factors affect the flow either unidirectionally, increasing or decreasing it, or in opposite ways. In addition, the impact of anthropogenic factors, including the regulating effect of reservoirs and water consumption, is comparable with the impact of climatic factors and even exceeds it in many cases.