Influence of Precipitation and Air Temperature on the Amount of Drainage Run-off

*The article presents the analysis of the influence of the fluctuations of main climatic factors (temperature, amount of precipitation) on the drainage in time, and analysis of distribution of drainage run-off during the year. The data of 42 years on drainage run-off and data on precipitation and temperature of the hydro meteorological station are used in this work. The drainage run-off mainly depends on the climatic conditions, drainage degree, origin of soil, grown plants, etc. High precipitation and low temperature during warm season cause increase of the run-off. In the cold season the run-off increases together with increasing air temperature. The analysis of run-off of five drainage systems of similar size (each area is from 0,41 ha to 0,45 ha) and comparison of precipitation per year and during the warm season (IV – X months) show variarion of the correlation coefficient between these values in different stations from 0,47 to 0,54. The characteristics of the drainage run-off change together with meteorological conditions. The run-off has the tendency to increase in winter and to decrease in spring. In winter the amount of drainage run-off increases significantly (from 12 % to 49 %), while the changes in the warm season are not so evident. The biggest changes of air temperature are in winter months, while the changes in the warm season are not so clear. The amount of precipitation increases in cold season and decreases in warm season, whereas the annual amount of precipitation changes only a little. The rise of air temperature and ocean level is one of the main, but not the only characteristics of global changes. The values of almost all climatic indexes (precipitation, air humidity, snow cover, etc.) are going to change. The climate is changing, thus, it is very important to react and to adapt so that the losses caused by climatic changes were as small as possibleVytauto Didžiojo universitetasŽemės ūkio akademij