Vízügyi Közlemények, 1970 (52. évfolyam)
4. füzet - Rövidebb közlemények és beszámolók
1 (ÔV <2 Ut 1 q = (1 — c)hv Assuming further the momentum condition for the fluid phase as ôv\ ôh V 2 dz / m V = (9) ô X J ô X c 2 h ô X the unknown quantities v, c. h and z involved in the set of equations (6), (7), (8) and (9) can be determined, and assuming the corresponding initial and boundary conditions, the solution can be programmed into an electronic computer. 2. Estimation of the process of silting using semi-empirical formulae As is well known, a great number of empirical relationships has been published in the literature for the estimation of sediment transporting capacity and consequently the process of silting. The majority of these is, however, valid only for the conditions for which they were developed and when applied under other circumstances, they yielded fully inconsistent and therefore unreliable results. One group of the relationships published so far is based on information derived for observations under particular field conditions, or in the laboratory, whereas the formulae based on the well tested theory of suspended sediment transportation may be grouped into the second. The discussion of the problem will be started with the formulae classified into the second group, which are beyond doubt of much greater interest. In this case the theoretical foundation offers the hope for generalization at a substantially higher level and consequently the application to particular cases may be facilitated. E. T. Dsharbashycin, V. C. Sanoyan and V. N. Shamagorcyan [3] departed in their study from Eq. (1), and by introducing Eq. (6) developed the condition describing the sediment transporting capacity of flow (the state of limit saturation) in the following form (10) w g n where A is an empirical coefficient to be determined experimentally. The solid discharge is expressed in term of the streamflow Q in the form Q c = С Q. In channels of constant cross section, using Manning's empirical relation, the solid discharge is obtained in the form 46/6 v Q c = A — Q m k 12/ 5 w g b 3/ 5 or Qc = Q m ß (И) The validity of this relationship has been verified by the authors on the basis of a nine-year record observed on the Marmeric river, in the 73
