Rahmatullina E. The hydrological regime of the rivers of the Southern Bug River catchment in winter period in conditions of climate change

The thesis focuses on research of the spatial-temporal changes of the characteristics of the hydrological regime during the winter period in conditions of climate change in the Southern Bug River catchment. The proprietary algorithm of research of these characteristics is proposed by author. The long-term changes of the surface air temperature and precipitation in the catchment are analyzed. The tendency to increase of the air temperature over the past decades, and change of precipitation amount during the cold half-year (the increasing in autumn and the decreasing during the spring flood) has been detected. The analysis of characteristics of the hydrological regime of rivers showed that changes of these characteristics correspond to changes of the components of the water-thermal balance, namely, to the increasing of water temperature in the rivers of researched catchment. The water content of rivers has been increased in autumn and has been decreased in the period of spring flooding due to changes of amount of the precipitation. The velocities of runoff have been decreased during of all the time intervals of winter period. The estimation of the future changes of characteristics of ice and thermal regime of rivers has been done based on the calculated relations these characteristics and projections of changes of average and maximum surface air temperature for the period 2031-2050. As the result, the tendency of increasing of surface air temperature will continue for the forecasting period (2031-2050).