ИСТИНА

Abstract in English. The paper assesses possible floods characteristics changes of the Eastern European Plain (EEP) in the 21st century according to Atmosphere-Ocean General Circulation Models (AOGCM), which is the main method for the ultra-long-term forecast of river flow in climate change conditions. Only data of AOGCM on precipitation and temperature were used, as the river runoff data is reproduced with significant errors [1]. Assessment of flood runoff depth changes was carried out according to the indicators of the incoming part of the water balance - the maximum snow cover water equivalent and precipitation of the cold period. An algorithm [2] has been developed to estimate the snow cover water equivalent that which converts daily air temperatures and precipitation into daily snowfall values. Flood runoff depth variability index was calculated based on the premise that the most important climatic factor determining it is the variability of precipitation over a cold period.