Vízügyi Közlemények, 2002 (84. évfolyam)
1. füzet - Koris Kálmán: A hazai hegy- és dombvidék kisvízgyűjtők árvízhozamainak meghatározása
A hazai hegy- és dombvidéki kisvizgyűjtők árvízhozamainak meghatározása 75 Determination of the flood flows of small Hungarian mountainous and hilly catchments by Dr. Kálmán KOR1S C.E. The determination of design flood flows is one of the most important tasks of technical hydrology. There are two ways of solving this task: The calculation of the maximum (the largest possible) flow, or the consideration of a flow value of given probability as the design flow. Most of the techniques relay on this latter, considering a flow of given probability as the design flood and using it as the basis of subsequent planning. The way of doing this way of flood calculation depends on the available hydrological data (Flow vs. water stage). If long flow records are available, then the methods of hydrological statistics can be followed. If the flow record is short then one may have to utilise the full stock of tools of hydrology. Nevertheless, the most frequently occurring case is the total lack of data, which require the use of experimental methods. In the Hungarian small hilly catchments we usually use the Csermák method, which has been developed in the early 1950-ies. However, considering the fact that this method is 50 years old and the hydrological conditions have also changed during this period, the necessity of developing new procedures became timely. This is also supported by the fact, that during the past decades quite a large stock of flow data and long time series became available The work started with the creation of the geographical database of the catchments in con• cern. Namely, the geographical data (Table 4.) will be the basis of the hydrological analogy to be used for the determination of the design flood flows of the yet unknown catchment basins. This is followed by the determination of the hydrological database, time series, of those catchments, which were subjected to investigations ( Table I.). The basic data of the empirical tools are derived from the hydrological-statistical processing of the data of those catchments, which have long flow records. The results of the investigations indicated that the small Hungarian hilly catchments could be grouped into well distinguishable runoff regions (Figure /.). The runoff functions have been developed for each of these regions. They relate the flood flow of 5% probability of occurrence to the area of the catchment basin. The functions of the form qs»/ 0=f(A) were determined for each of the six runoff regions (Figure 2.). These functions allow the calculation of the flood flow of p% probability with the formula Q p%= «,<75%^, where ai is a multiplier depending on the probability in concern (Table V). The general form of the flood flow formula is Q$%= a A l h, and the constants of these equation were given for each runoff region (Table VI.). It should be emphasized that the general nation wide equation (combining all runoff regions) for the flood flow of p= 1% probability of occurrence is Q\%= 136A 0 1 and this differs from the earlier equation, where the catchment area A was on power 0.5 only. * * * Ermittlung der Hochwasserabflüsse von kleinen Einzugsgebieten des ungarischen Berg- und Hügellandes von Dr.-Ing. Kálmán KŐRIS Eine der wichtigsten Aufgaben der technischen Hydrologie besteht in der Ermittlung von Bemessungshochwasserabflüssen. Es gibt zwei mögliche Lösungen des Problems: einerseits die Berechnung des maximalen (höchsten) Abflusses, andererseits die Berücksichtigung eines Abflusses bestimmter Wahrscheinlichkeit, als Bemessungswertes. Die Mehrzahl der Verfahren
