Hidrológiai Közlöny 1949 (29. évfolyam)

1-2. szám - E. MOSONYI, D. Eng.: Natural storage effect in the mountainous drainage areras of the Carpathian Basin

(3) If V means the totál annual run-off, expressed in m

3, the following equation may be written: from where m-\-ö T m-j-6 qk (i) (5) where q

k — V/T is the so-called minimum mean discharge, i. e. the mean discharge of the arid and at the same time decisivte year in view of storage. Setting equation (5) into (3) the theoretical hydrograph deciisive for storage capacity can be expressed as m+6 (6) For computing reservoir capacity it is customary to plot the mass curve of discharges. In. the examined case the mass curve can be explained mathematically by integrating function (6) as follows (Fig. 2.): / t T qrlt Totál Bun-Off Vízmennyiség m

3 Storage Year Tározási év t' v=V—v'= V— J qdf = hí+6 m—1 í'

7 —]• If the necessary storage capacity in case of uniform oonsumption is wanted, the maximum value of the m stored wa'ter quantity is to be determined. The :0 adherent time, reckoned backward from the end of the storage year, out of the differential equation ds ír or, what is essentially the same, determined from relationship: is as follows: ' t' 0-7230 T Fig. 3. ábra. Dctermiration of the equation of the eharacteristical discharge mass-curve. A karakterisztikus vízhozam integrál görbe egyenletének meghatározása. 0 and computed from the beginning of the storage year <

s = 0-2770r~ 274 = 3 raonths. (9a) So formula (8) gives for the necessary reservoir capacity, the following value: S — A-max — (lü> m—l f T / T 1 1 naioa wl_

1 „ Y Introducing now the dimensionless coefficient m

—l m-f-6 equation (10) can be written as S = 062<pq

kT or S = 0-629-7. Stfbstituting (11) and f = T <P - (11). (12} decisive theoretical disclvarge-function is T-t (12a), t into (6), the ••qk - — ((13) and the characteristic mass curve suggested by the author can be expressed in the form ' T-t V VI 1 T-t V— V\-jT + v—jr(14) Finally, with the above mentioned substitutions the stored water qumitity against timte can be written as T—t ( T-t V - f V T -(

J T (15) (?) V /

ffl / £'7 \ In the watersheds belonging to identical climate zones, the natural storage effect may becharacterised by the above introduced cotefficient: <p. This dimensionless coefficient explains the hydrological effect of topographical and geological conditions upon natural storage and it is evidently characteristic for the relatíve extremity of run-off. Lests extreme run-off is defined by a smaller, while more extreme run-off by a larger f coefficient. The f value itself and its variations are deducted by the author from actual mass curvtes and measurements. The 'theoretically possible variation of proportion (2) of maximum and minimum discharges belonging to the theoretical hydrograph can be expressed as 00 > m > 1 while according to (11) the limits of the coefficient are as follows: 1 > f > 0. Since <p explains the maximum deviation between the characteristic mass curve and the straight mass line of totally equalizted run-off, it may be called natúrul storage coefficient. 12