Аннотация:The analysis of rivers runoff changes in the Oka and Don basins has been
performed for various phases of the water regime as well as the causes of these
changes during 1945–2014. An increase in the minimum discharge of summer
and winter base flow has been revealed, as well as decrease in the maximum
floods' flow rates with the relative constancy of annual runoff (Don) or
its growth (Oka). This redistribution of runoff between the phases of the water
regime led to a decrease in the degree of uneven flow within the year, especially
noticeable in the Don basin. At the same time, over the same period, the runoff
of the summer base flow has become less uniform. With the help of satellite
gravimetry data, the connection between water discharge and basin moisture
reserves is revealed. A significant decrease in total basin water reserves in the
Don basin for 2002–2016 (more than 150 mm) has been established that can
serve as a factor of protracted shortage of water in the future.
