Assessment of runoff characteristics changes of small and medium-sized rivers in Central Yakutia under the climate change influence

Abstract

The response of river catchments located on the territory of Russia to climate change in recent decades has been expressed in the emergence of multidirectional trends in the series of annual runoff, maximum water discharges and the value of winter runoff. However, the response of small and medium-sized rivers to the ongoing climate warming has been poorly studied, in contrast to large rivers. In this paper, a comprehensive analysis of the climatic and hydrological characteristics of small and medium-sized rivers of Central Yakutia as well as an assessment of the climate change impact on the river runoff characteristics in various conditions of the region were carried out. It has been established that the revealed positive trends in temperature correspond to the trends typical for the rest of the Russian Federation. The response of the runoff of small and medium-sized rivers to climate change is most significant in the winter-spring months of the year: there is an increase in runoff in the spring and winter periods and for the year as a whole. A feature of the response of the river catchments of the study area in comparison with the European part of Russia and southern Siberia is the presence of statistically significant trends in the series of annual water discharges for most of the studied water gauges. The most noticeable changes (as a percentage of the base period) occurred in the annual runoff of small rivers, because small rivers respond most quickly to external influences. Its expressiveness is determined not only by the degree of changes in climatic characteristics, but also by the features of runoff formation in the watersheds of the study area, in particular, the presence of permafrost.