Hidrológiai Közlöny 1949 (29. évfolyam)
1-2. szám - E. MOSONYI, D. Eng.: Natural storage effect in the mountainous drainage areras of the Carpathian Basin
A Nemzetközi Geodéziai és Geofizikai Unió Hidrológiai Szakosztályában előadott magyar tanulmányt mutatja be az alábbi értekezés. A tanulmány eredményei nagy mértékben könnyítik meg a vízgazdálkodási munkák előtanulmányainak lefolytatását. D. C. 551.491.7(234.37) Natural storage effect in the mountainous drainage areas of the Carpathian Basin* By E. MOSONYI, D. Eng. Drainage ar'eas in the eastern region of the 'Carpathian Basin have been investigated by the author with special regard to hydrological design of larger storage reservoirs. In connection with the determination of necessary storage capacity for an annual reservoir, it is the 12 month period subsequent to the míelting of the snow that is to be taken into consideration. To distinguish this period from the calendar year, the term „storage year" may be introduced. The storage year in the Carpathian Basin begins usually in the month of March. The necessary storage capacity depends on the one hand on the run-off conditions of the examined watershed, and on the other hand ön the tempóra! distribution of consumption for any utilization purpoóe (power generation, irrigation, navigation). Furthermore the size and temporal distribution of run-off, which is expressed by thte so-called hydrograph of diseharges, is influenced by two main groups of natural elements: meteorological conditions and factors of natural storage effect in the watershed belonging to the dam sitte. The difference between the temporal distribution of precipitation and that of run-off is brought about by the natural storage effect which implies the influence of topography, degree of forestation and geological conditions in the drainage area. It is obvious that with any increase in the natural .storage effect the reservoir capacity necessary for run-off equalization decreases. Therefore it is very important for the designing engineer to clear up accurately hydro-geological relationships of the natural storage effect. In caste of watersheds having approximately identical topographical and forestation conditions and being situated in identical climate zones, i. e. where similar temporal distribution of precipitation prevails, the size and geological structure of the watershed are decisive for the natural storage efffect. In his examinations the authors's first'aim was to find the laws of the hydrograph of the decisive storage year. For this purpose the meteorological and hydrographical conditions of 1942—43 were exceedingly favourable. On the basis of longperiod hydrographs for the Eastern Carpathian Basin it has become obvious that in 1942—43 minimum and mtean diseharges of several watercourses were below the corresponding figures of the wellknown arid year of 1904. Consequently the storage year beginning in the spring of 1942 was decisive as far as totál annual run-off is concerned. Based on records of the past 40 years the author proves that for the examined area the aforementionted storage \ year may be regarded as decisive even in view of temporal distribution of diseharges. According to the measurements and theoretical investigations of the author, the most unfavourable hydrograph for determinating necessary storage capacity can bte approximated by a parabolically falling curve (Fig. 1.) expressed by the function: q (ms/sec) = g 0 + ct' a (1) where q and t mean the variable values of discharge and time respectively. The discharge corresponding to the beginning of the storage year is q^qo + cl". (la) Substituting the m—— (2) ?0 index of the extreme values, function (1) can now bte written in form Theoretical curve approx mnttng (he natural flow most unfavourable .for storage. Hiirograph applied for reckonin characteristical mass-eurve. A tarozas tekintetében lefi-kcdvezötleiiebb természetes vízjárást megközelítő elméleti grürbe. A karakterisztikus v)zhozamintegrál meghatározásira figyelembevett vízhozam-idősor, q Discharge Vízhozam m'/sec T Storage Year Tározási év * Study presented to the Association of Scientific Hydrology oft the International Union of Geodesy and KJeophysics on occasion of its Oslo Congress. (1948-0 Természetes tározóhatás a Kárpát-medence hegyvidéki vízgyűjtő területein. Irta: Dr. Mosonyi Emil. (Magyarnyelvű kiivonat az 53. oldalon.) 11
