Vízügyi Közlemények, 1948 (30. évfolyam)
2. szám - VII. Szakirodalom
Formulae (28) and (29). This mass curve as shown in Figure 20. may lie described as characteristic mass curve in view of annual storage. In case of uniform consumption variation of stored water (s) is explained by Function (30). After a substitution of Formula (31), equation (32) gives quantity of stored water, while (33) gives the theoretical hydrograph in a simpler form as follows: T — t 1—Ф+7Т" (33) Як T With application of the accepted susbtitutions, equation of the characteristical mass curve reads as follows: (34) V = V t T T T -cp T — t T Maximum quantity of stored water is reached in U = 0-2770 T ^ 3 months. (35') As a final result this maximum value means needed storage capacity as well. Consequently: (36) s ma x = S = 0-62 cp q k T = 0-62 cp V Relative fullness of the reservoir is explained in accordance with Formula (38) by Figure 21. as function of the months of the storage year. The dimensionless coefficient cp both in the deduction and in the resulting formulae is characteristic for the relative extremity of run-off. Less extreme run-off is characterised by a smaller, while more extreme run-off by a greater cp value. The value cp itself and its variation are deducted by the author from actual mass curves resulted by hydrographic records and measurements. It is obvious even 011 the basis of theoretical considerations that any increase of the drainage area causes a decrease of coefficient cp which is essentially influenced also by the perviousness of the drainage area. Perviousness of the drainage area is dependent primarily 011 geological conditions, but it is effected by topographical conditions and forestations as well. The author proves the logarithmic relation between the extension of the drainage area and coefficient cp as explained in Formula (39) which he uses in the forthcomings in the form: Log F (40) To Log F t Figures 23—35 show the mass curves decisive for annual storage which could have been accurately drawn up through measurements. Values of (p 0 and F 0 were computed with data which had been derived from the above Figures and laid down in Table VI whereby proof is given of the aforementioned relationships. Figure 22 shows how to select the mass curve decisive for annual storage relating to the Visó-Biver and at the same time it proves that the 1942—43 storage year was really decisive in the examined case. Figure 36 in accordance with Formula (36) indicates the points which correspond to cp values computed from the actual run-off and gives proof of supposition under (40). The three straight lines in it correspond to: A) the drainage area of impervious character, Formula (42); B) „ „ „ „ semi-pervious „ ,, (43); C) „ „ „ „ pervious „ „ (44). Drainage areas adherent to stations 1, 10 and 11 contain regions of different character (See Tables VI and Figures 23, 32 and 33). It is evident that points characteristic for the above stations fall in between the straight lines. Coefficient 7 characteristic for drainage areas comprising regions of different character (F A + F B = F) can be computed with Formulae (45), (45') and (45") depending on whether annual precipitations (A) for the
