For more than 40 years estimated characteristics of rivers’ maximum runoff for rain and spring floods in Ukraine have been determined using the regulatory document SNiP 2.01.14-83. This regulatory document is based on use of reduction formulas and maximum intensity formulas .
Use of reduction structure for rain and spring floods of different reduction have no relevant grounds since in both cases we deal with calculation of maximum water discharge forming the part of unimodular hydrographs. In addition, a calculated parameter of “friendliness” is determined for spring floods by use of hydrological analogues, which, by the way, are assigned rather provi-sionally. Regarding rain floods the impact in the form of coefficients of analogy is replaced by the runoff module taken for a provisional catchment area. In methodological terms, in contrast to the “friendliness” coefficient of the spring flood determined by the method of hydrological analogy, module (for rain floods) is represented by a map of isolines. More remarks can be voiced with regard to the methodological base of determination of maximum mod-ules of rain floods runoff within small catchment areas. The main drawback relating to the use of maximum intensity formula consists in the fact that natural process of transformation of rain floods “precipitation – slope inflow – river channel runoff” is replaced by the operator of “precipitation – river channel runoff”.
The authors of this article offer a universal approach to substantiation of the structure of the formula to determine the characteristics of maximum runoff of rain and spring floods.
The original theoretical model for hydrographs of rain and spring floods is accepted as unimodular non-linear triangles.
For the first time all the components of calculation equations of modules of maximum runoff of rain and spring floods are described by the same equations and differ only in numerical values of the parameters. The proposed scientific and methodological base for determination of modules of maximum runoff of rain and spring floods underwent practical test and is recommended for use when preparing a new Ukrainian regulatory document replacing SNiP 2.01.14-83.
The article deals with the problematic issues related to the definition of the design characteristics of the maximum runoff of rain and spring floods the rare probability of exceedance in the case absence of direct observations for hydrological regime of rivers. A brief review of foreign and domestic methods to determine the maximum runoff of the rivers is discussed. A new calculated and normative framework based on the theory of channel isochronous with using geometric model of slope and streamflow hydrographs are proposed. The formulas proposed by the authors is recommended for practical use, as a supplement to a new regulatory document, which is being developed in Ukraine.
It is performed statistical processing the series of maximal runoff for rivers of the Dniester-Prut interfluves basin.
The article discusses the scientific and methodological approaches for creating a computational technique for determining the characteristics of the high flow of small rivers.
The article considers scientific-methodical approaches associated with substantiation duration of influx from the slopes during the formation of extremely high rain floods and spring floods.
It is performed statistical processing the series of maximal runoff for rivers of the Dniester-Prut interfluves basin. There is also performed statistical analysis of series of the maximum flow layers and its territorial generalization. .
The scientific-methodical aspects of calculation of maximum runoff from elementary watersheds in the article
are examined.