МАКСИМАЛЬНЫЕ ГОДОВЫЕ РАСХОДЫ ВОДЫ МАЛЫХ РЕК СЛАВСКОГО РАЙОНА КАЛИНИНГРАДСКОЙ ОБЛАСТИ

Abstract

Purpose: to restore the series of maximum annual water discharges (MAWD) of small rivers in Slavsky district Kaliningrad region and determine the calculated values of MAWD with the necessary availability for designers. Materials and methods. The basic material – observational data of Roshydromet for water discharges on the Zlaya, Osa and Nemoninka (Nemonin river basin) rivers and on the Instruch river. The Instruch river was used as an analogue for the restoration of the MAWD on the Zlaya river for a few missed years of observation. The river Osa has the shortest series of observations, for its restoration, as well as for the Nemonin river, the Zlaya river served as an analogue. A hypothesis that the MAWD of the rivers of the Slavsky district obey a three-parameter gamma distribution (Kritsky-Menkel) was put forward. To solve the system of integral equations, a previously developed numerical method was used. Results. A close stochastic relationship between the MAWD of the tributaries of the Nemonin river has been determined for years of joint observations. This made it possible to obtain the restored MAWD series for 1955–2019. The probability curves of three small rivers were constructed, and the hypothesis on possibility of using the Kritsky-Menkel distribution was confirmed. According to the analytical expressions of the specified distribution, the calculated values of the MAWD of the given exceedance probabilities were found. Conclusions. The hydrological characteristics of the studied rivers of the Nemonin basin are strongly influenced by the functions of water intakes of draining reclamation systems. Due to the impossibility of dividing the peak annual discharges into the maxima of rain and melt water for each river, a single series of MAWD was restored, regardless of their origin. At the tributaries of the Nemonin river, the ratio of maximum discharges to average annual ones is noticeably lower than that of the Instruch river, which is under the similar hydrological conditions, but is not subject to such a strong anthropogenic impact. The calculated MAWD modules of the given exceedance probabilities can be used in the design of drainage systems and hydraulic structures.