Peculiarities of annual internal distribution of small rivers’ runoff (on example of the Udy river)

Abstract

Formulation of the problem. Water is the basis of life and, therefore, the questions regarding the definition of annual runoff distribution as a whole in Kharkiv region and in the context of individual river basins remain actual. The study of the domestic annual runoff is due to the fact that the Udy River basin belongs to the poorly watered areas, and in recent years climate change leads to a decrease in drainage during the year, including seasonal runoff changes, which may cause water supply problems in the economic sphere. The purpose of the article is to study modern features of the annual distribution of the water runoff of the Udy River basin. Presenting main material. The article deals with the peculiarities of the formation and changes in the annual flow of the river Udy basin for 35 years (1991-2015). Having analyzed the average monthly water consumption in the Udy basin, it can be noted that the annual distribution of drainage for this period is close to all rivers - typical spring flood (March), summer (August, September) and winter (December, January) months. However, the share of spring water in the Udy basin in the annual volume of drainage has decreased and the supply of rivers has changed. In connection with climatic changes, namely, the decrease in winter rainfall, there was an increase in the share of underground supply which contributed to its alignment with the share of snow intra-annual distribution. Conclusions. Having studied annual distribution of the river basin’s flow in the Udy River, it has been found that the share of spring water in the annual volume of drainage decreased from 42-36 to 36-25 %. In recent years, there has been less precipitation in winter and, therefore, snow supply is not prevailing, and there is an increase in the share of underground supply.