СЕРЕДНІЙ РІЧНИЙ СТІК ВОДИ РІЧОК УКРАЇНСЬКИХ КАРПАТ У БАГАТОВОДНІ ТА МАЛОВОДНІ ФАЗИ ВОДНОСТІ

Abstract

he assessment of the average annual runoff of the rivers of the Ukrainian Carpathians in the high-water and low-water phases of water was carried out on the basis of a stochastic analysis and the identification of characteristic patterns of alternation of such periods within the boundaries of the Tisza, Dniester, Prut and Siret river systems. The study was carried out using a methodological base based on statistical means of generalization, data systematization, methods for estimating temporal random sequences, methods for analyzing the long-term variability of time series of water runoff characteristics and identifying their structure. As a result of the study, the variability in the structure of the time series of the average annual water discharge of the rivers of the Ukrainian Carpathians is clearly revealed. Such variability is similar for rivers within the studied river systems and is characterized by common patterns of stochastic relationships and cyclic fluctuations. The high reliability of cycles with periods of 29 ± 2 years indicates a stable recurrence of periods of high and low water content. The graphs of the relationships between the average annual water discharges during the periods of high and low water content and their average long-term values for the rivers of the Tisza, Prut and Siret river systems on the right bank of the Dniester showed that the qualitative characteristics of such relationships are assessed as very high. The estimates of water discharge in the water phase for the rivers of the Tisza, Prut, Siret and the right bank of the Dniester basins were checked using regression equations in comparison with empirical data and their high reliability (the probability of not exceeding probable deviations in dry periods was 77%, in high-water periods – 95%), which made it possible to generalize the probable expected average water discharges in the high-water and low-water phases of the cycle, depending on the average long-term values for the rivers of the studied basins of the Ukrainian Carpathians. Such generalizations can be used for prognostic estimates of possible values of water discharge in high-water and low-water phases for any river of the Ukrainian Carpathians. At the same time, it is necessary to take into account in which system of rivers it is located, to know the average long-term water discharge and the time frame and the chronology of the water phases.