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Abstract

The paper presents a simple method for the determination of design discharge as a groundwork in preparing studies and project documentation for torrent training structures and stream regulation. The design discharge is to express the degree of protection of a structure and its vicinity, and its numerical value is one of basic groundworks for dimensioning the structure. It is usually stipulated by the Czech Hydrometeorological Institute (CHMI); catchments sized below 5 km2 may use some of well-proven methods or formulas. A simple method was chosen, which dwells on Dub’s exponential (regional) formula (DUB, NĚMEC 1969; ŠKOPEK, NOVÁK 1977; JAKUBIS 1993; ZUNA 2008) and was modified by ZUNA (2008) through the solution of a pair of exponential equations. A statistical survey and logical evaluation of the applicability of this method were made on a set of eighteen partial catchments in the southern part of the White Carpathians. It is possible to conclude that catchment parameters for the southern part of the White Carpathians are B = 9.2 – 10.2; n = 0.45 – 0.54; and a = 0.55 – 0.46 respectively. Nevertheless, as to the range of resulting values, the applied method can be considered applicable only for the purpose of studies. In establishing design discharges for the purposes of sizing river channels, torrent training structures and stream regulations it is applicable only in the case when an analogy is in question to the basic hydrological values of partial catchments of the same stream. Similarly, the basin parameters are calculated for a theoretical 0% forest cover using the correction factor (HORSKÝ 1970).