Vízügyi Közlemények, 1991 (73. évfolyam)

2. füzet - Domokos Miklós: A nyugat- és észak-európai országok hidrológiai együttműködése (FREND) magyar szemmel

182 Domokos Miklós 1981, Figure 4 ), elaborating the normalized flood-duration curves (Figure J) and flood statistics (Figure 6) of these clusters. The construction of the empirical relationship (1) for the estimation of the mean high flow (KNQ) - needed for the practical application of the above normalized curves - falls also into this category. In the chapter dealing with regional low flow investigations, the flow duration curves of drainage basins of different geological structure are typified (Gustard 1990, Figs. 7 and 8),among others, along with their recession-duration curves (Figure 9). An empirical relationship between the annual characteristics of the water budget is also presented (Figure 10), along with a relationship between multiannual average runoff Ä

a

a and its coefficient of variation C

v (Figure 11). The subregions of the FREND region are typified according to their low flow regime. Next, the stations investigated (Figure 12) are listed into clusters on the basis of their low flow characteristics, and empirical relationships for each cluster (Figs. 13 and 14) and for the total FREND region (Figs. 15 and 16) are presented (Eqs. 4 and 5). The next chapter deals with the research results of experimental drainage basins, in relation to the chapter on low flows, discussing base flows as separated by the Kille (1970) method (Fig. 17) and analysing the properties of recession curves (Fig.18). Empirical relationships for the estimation of these characteristics were also elaborated (Eqs. 6. and 7). According to the author the empirical relationships elaborated for a region of 2.5 million km

2, can not - in general - be more reliable than those similar ones available or derivable for the territory of any country or subregions of it, by making use of all available local experiences (Lászlóffy 1954, Csermák 1957, Kovács (geogr.) 1983, Gillyénné-Hofer and Domokos 1985). Hungary, due to her geographical situation, is interested mostly in the completion and further development of the several international cooperative hydrological activities under way in the Danube Basin of 0.8 million km

2. Among these, an outstanding activity has been dedicated to the „Danube Monograph" that the hydrologiste of the eight riparian countries wish to extend by 1992 with four more volumes, as supplements to the first volume published in 1986 (RZdD 1986). The author presents a detailed comperative analysis of the FREND report and the Danube Monograph, pointing out common features as well as differences. In this latter context it is pointed out that although the Danube Monograph also contains some regional generalizations of a different type(Figs. 19-21), it does not include regional empirical relationships on the basis of drainage basin characteristics of the type of those presented in the FREND report. On the other hand, the FREND report lacks a synthetizing water balance chapter of the type included in the Danube Monograph (Domokos-Sass 1990). As a final conclusion, the author suggests a further concentration of Hungary's international cooperative hydrological efforts on the successful completion of the relevant projects of the Danube Basin, for which the methodological experiences of the FREND project should be utilized as soon as possible. *** Das hydrologische Projekt FREND der west- und nordeuropäischen Staaten aus ungarischer Sicht von Dr.-Ing. Dipl.-Math. Miklós DOMOKOS Im Rahmen des Internationalen Hydrologischen Programms der UNESCO haben die Hydrologen von dreizehn west- und nordeuropäischen Staaten, durch das Hydrologische Institut von Wallingford (UK) koordiniert, nach einer vierjährigen gemeinsamen Arbeit den Bericht des regionalen hydrologischen Programms FREND (=FIow Regimes from Experimental and Network Data) im Februar 1989 fertiggestellt (FREND, 1989). Dieses auf den Durchflußzeitreihen der 2061 Beobachtungsstationen der sich auf 2,5 Mio km

2 erstreckenden FREND-Region (Bild 1) sowie auf den kennzeichnenden Parametern der Einzugsgebiete (Bild 2) basierende interna-