ИСТИНА |
Войти в систему Регистрация |
|
ИСТИНА ЦЭМИ РАН |
||
The current changes in the water regime of rivers are obvious now. In the European part of Russia they are manifested in different ways in various regions. The main trend that is observed in most river basins is the "leveling" of annual hydrographs. It resulted in a decrease in the spring months flow associated with the interception of melt water by thawing floods. Simultaneously an increase in the low water period during winter and summer occurred. Reducing in the depth of soil freezing, caused by warm winters, lead to higher groundwater nourishment. At the same time, the loss of melt water to surface retention arise as well as evaporation. Almost all the seasons of the year, the number of flood peaks increases. Floods are superimposed both on the rise and the decline of seasonal flood wave, making it difficult to separate it as an independent phase of the water regime. Changes in the seasonal characteristics of the flow are most clearly manifested in the Don and Oka basins. A significant transformation of the water regime is evident to the rivers of the north-west. To a lesser extent, the described patterns are typical for the northern rivers and the eastern part of the European Russia - the Kama and the Ural Basin.