Vízügyi Közlemények, 1959 (41. évfolyam)

4. füzet - V. Kisebb közlemények-Ismertetések

(17) Eq. (15)—or into other practicably selected relations of three, respectively two variables

—was found to yield results in a faster and more reliable manner. The analysis of component functions is exemplified in Fig. 5. Different colours have been applied to denote plotted values according to their respective group, in the original work sheets. Component functions may hereafter be combined in a common system of coordinate axes (13), although the simple, or weighted, mean of values obtained from separate three-variable charts can also be used directly for practical purposes (see Fig. 6, respectively Eqs. (16) and (17)). An example for resolving gage relationships involving several variables, and expressed by Eq. (6) is given by Eq. (18) and by Fig 7. The analysis of component functions of gage relationships derived from discharge data is illustrated in Figs. 8 and 9. An advantage of the interpretation according to Eq. (13) is that the resulting relation can, in general, be determined by resolving iL into component functions containing two variables only (Fig. 10). A most simple check on the reliability of relationships determined by graphical correlation is offered by comparing the closeness of the relations determined for the same variables by the aid of different parameters. An example for a similar control is given in Fig. 11. Essential information for the construction can be gained by correlating the same set of points according to various parameter and by checking the agreement between sets of curves thus obtained, fsometrical lines in Fig. 12 have been constructed on basis of the stage differences H

1

—hi * (where II l is the peak observed in the upstream section and h^ is the stage observed at the same time in the downstream section). The same set of points has been labelled in Fig. 13 according to values h-, , whereupon the curves H

1 -ht

1' have been traced by simple transformations also for this case. (The curve II

1 = 100 cm has only been entered into the diagram.) As can be seen there is a'slighl discrepancy between the two sets of curves in Fig. 14 obtained by different ways. Gage relationships constructed according to Eq. (6) can be compared and improved in a similar manner (see Figs. 7 and 15). Results obtained graphically can further be checked by using discharge data instead of stages (Figs. 10 to 20). For instance, Fig. 18 characterizing the attenuation of the peak flood discharge over a long reach without inflow may be obtained both by labelling observation data, as well as by using three-variable relations according to Figs. 10 or 17. Another important aid in graphical correlation is the solution of three-variable relations by means of resolving them into such involving no more than two. The three-variable relationship ilustrated in Fig. 20 can be derived either by direct graphical correlation of data, or from I he two variable relations according to Fig. 19. . Of course, gage relationships derived from stage observation data yield to a similar treatment. E. g., the three-variable relation according to (15—a) can also be derived from the two-variable relations 7/l

û

) = /(//,) and Il{

h

) = / (MP as in Fig. 21. (Author's summary translated by /. Szilvássy C. Ii.) QUELQUES QUESTIONS RELATIVES À LA CONSTRUCTION ET À L'INTERPRÉTATION DES LIGNES DE CORRESPONDANCE ENTRE ÉCHELLES LIMNIMÉTRIQES Par K. Szesztay

, candidat des sciences techniques et T. Zsuffa (Voir figures et tableaux pp. 79—105 du texte hongrois) CDU, 551.482.215 Les lignes de correspondance entre échelles exprimant la relation entre les niveaux des plus hautes eaux se produisant aux profils d'un cours d'eau se suivant l'un l'autre constituent un important auxiliaire de la prévision des crues. Les lignes de correspondance à deux variables entre deux échelles voisines peuvent se résumer dans un profil en long suivant fig. 1. Ce mode de représentation peut également servir (

fig. 2 et 3

) pour d'autres données caractérisant le régime des eaux et le lit (p. ex. l'aire F des profils, la vitesse du courant v et le débit Q pouvant se calculer connue produit de ces deux).