Influence of Meteorological Factors on the Seasonal Runoff of the Kolyma River

The main patterns of the changes in the Kolyma River runoff regime for the period of hydrological observations (1933–2018) are estimated, the beginning of its high-water phase is determined (1984), and the rate and magnitude of the change in river runoff in the annual and seasonal context are revealed. The annual river runoff is increasing at a rate of 4.95 km3/10 years, its volume during the high-water phase has increased by 37% against the background of increasing interannual variability. The analysis of the series of runoff volumes, air and soil temperatures, and total precipitation indicates that the annual and seasonal runoff of the Kolyma River reliably correlates with a set of meteorological parameters: the runoff characteristics in the cold season depend on the amount of precipitation in January of the current year; the volume of monthly runoff of the summer-autumn period is governed by the amount of precipitation in both the current and preceding months. The positive dynamics of the runoff coefficient in July–September points to an increase in the importance of liquid precipitation in runoff formation.