INTERANNUAL VARIABILITY OF ELEMENTS OF THE WATER BALANCE OF THE BASIN OF THE TRANSBOUNDARY RIVER ANGRAPA

Abstract

The purpose of this article is to assess the interannual variability of the elements of the water balance of the rivers of the Kaliningrad region for the period 1953-2020 using the example of the Angrapa River. The average annual air temperature and precipitation were determined by the weighted average method for 7 weather stations in the basin. The Ozersk weather station (from Russian points) with the highest correlation coefficient (r = 0,983) was taken as the base station. Data on average annual water consumption were taken from the Angrapa River hydropost in the village of Berestovo. The missing flow values have been restored by analogous rivers. According to the linear trend, there is a decrease in the average annual runoff, by 20 mm over 120 years. For the period under review (1953-2020.), the linear trend of annual precipitation showed an increase of 21 mm, the annual evaporation layer increased by 82 mm. The values of the annual runoff layer, the total evaporation layer and the moisture reserves in the basin synchronously follow the change in the precipitation layer, both in wet and dry periods. Calculations of the basin’s water balance over the past 10 years have shown a tendency to decrease average annual expenditures against the background of increased precipitation and total evaporation.