Change of ice regime characteristics on the rivers in the Upper Yenisei b
Reaction of the ice regime characteristics for the Upper Yenisey basin rivers on climatic changes during the last decades is considered. Four regions are delineated according to the trends of the river ice regime characteristics gradient. We found statistically significant reduction of the number of days when rivers cover by ice with average altitude of watershed area less than 1500 m. The dates of stable river ice formation have moved on later terms, on the average for 10 days, and the breakup of ice now begins 10-18 days earlier. The basic reason of the revealed changes is the increase in water discharges during the autumn and winter (low water period) and, consequently, growth of heat quantity contained in river water mass, and decrease in ice cover thickness due to reduction of the negative sum of winter air temperatures.