Runoff fluctuation in river basins of different size in regard to meteorological conditions

Abstract

It is very important to keep a close watch on river runoff, because this is one of the indicators that show changes in the climate. Meteorological conditions alter with climate getting warmer and therefore influence river runoff. The purpose of this article is to determine the influence of the changing meteorological conditions to the runoff of different size river basins. Two river basins are being analysed (Venta by Papile and Krazante by Pluskiai), both located in Western hydrological area. The average daily flow and meteorological data (precipitation and average temperature) are of the period 1968–2008. It shows the most watery years for the rivers and helps evaluate the influence of the meteorological conditions to the runoff. Statistical and regressive analysis and coefficients of correlation are established as well. Evaluated influence of percipitation is unquestionable though variable. Sometimes even a small amount of percipitation challenges big changes in runoff, though next time having big percipitation runoff flactuates just marginally. In large river basins such influence is noticable few days later, and in small ones percipitation often changes the runoff the same day.