Изменение продолжительности стока рек Центральной Якутии под влиянием потепления климата

Many rivers in the cryolithozone have no runoff in winter due to their freezing to the bottom at the river crossings or along a large length. The study of runoff duration is relevant in connection with the issues of water supply organization. Also, research on this topic expands the knowledge on the response of small and medium-sized catchments in the permafrost zone to climatic changes. Therefore, the aim of this study was to analyze changes in the runoff duration in Central Yakutia under the climate change influence. Eight river catchment with areas from 20.3 to 11 600 km² were considered as research objects. Trends in time series of hydrological and meteorological characteristics were assessed, and correlation analysis was carried out to identify the relationship between changes in runoff duration and volume characteristics and temperature and precipitation conditions at the watershed. Annual runoff increases in 7 out of 8 rivers, in four cases changes are statistically significant. There is an insignificant increase in the runoff period on 7 rivers
(1.3-4.8 days/10 years) due to the earlier runoff start date in spring and its later end in fall. The change in the runoff start date is caused by the increase in air temperature in April and May. The time of runoff end is influenced by precipitation of the warm period in some rivers and air temperature in autumn and early winter in others. Also, on 7 rivers the date of maximum daily water discharge shifts to earlier time (the change is statistically significant in three cases). The duration of summer drying increases on one river.