MALA M. M., MOSKALENKO S.O. ANALYSIS OF LONG-TERM VARIABILITY OF STATISTICAL PARAMETERS OF THE DISTRIBUTION OF AVERAGE ANNUAL WATER FLOW OF THE DNIESTER AND PRUT RIVERS
DOI: https://doi.org/10.17721/2306-5680.2025.4.4
Hydrology, Hydrochemistry and Hydroecology. 2025. № 4(78)
Publication language: Ukrainian
Authors:
Mala M. M., Taras Shevchenko National University of KyivMoskalenko S. O., Taras Shevchenko National University of Kyiv
The article studies the temporal variability of the main statistical distribution parameters (norm, coefficient of variation and coefficient of asymmetry) of the average annual water flow of the Dniester (near the hydrological station of the city of Zalishchyky) and Prut (city of Chernivtsi) rivers. At the points of the indicated stations, the periods of observation of river water flow are quite long. On the Dniester River – the city of Zalishchyky, water flow observations were made from 1882 to 2020 (139 years) and on the Prut River near the city of Chernivtsi – from 1895 to 2020 (126 years). The use of such long series contributed to the study of the long-term variability of statistical parameters. Based on the initial data, an analysis of the temporal variability of average water flow rates (norms), coefficients of variation and coefficients of asymmetry was carried out by comparing the indicators of the studied statistical distribution parameters for the entire observation period with the corresponding indicators of the parameters for individual 30-year climatic periods, namely, for the following periods: 1882-1900, 1901-1930, 1931-1960, 1961-1990, 1991-2020. The key results of the study show that the statistical parameters of the average annual water flow of the studied rivers are not stable over time. The study shows that the lowest multi-year variability among the main statistical parameters of the distribution of the average annual water flow of both the Dniester River – the city of Zalishchyky and the Prut River – the city of Chernivtsi has water flow rates and coefficients of variation. Asymmetry coefficients have more significant multi-year variability. It is known that the reliability of analytical distribution curves and calculated characteristics of the studied hydrological indicator of a certain probability of exceedance depends on the degree of variability and stability of the main statistical parameters of the distribution of series of random variables. The study indicates the risks of using short series of observations to determine the calculated characteristics. The results are of practical importance for reliable hydrological design and management of water resources in the basins of the Dniester and Prut rivers.
Key words: Dniester River; Prut River; average annual water flow; statistical distribution parameters; multi-year variability.
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HOW TO CITE
Mala, M.M., Moskalenko, S.O. (2025). Analysis of long-term variability of statistical parameters of the distribution of average annual water flow of the Dniester and Prut rivers. Hidrolohiia, hidrokhimiia i hidroekolohiia [Hydrology, Hydrochemistry and Hydroecology], 4(78), 43-50 (in Ukrainian, abstr. in English). https://doi.org/10.17721/2306-5680.2025.4.4