Vízügyi Közlemények, 1970 (52. évfolyam)
4. füzet - Rövidebb közlemények és beszámolók
The formulae suggested by I. G. Samov [24], 1.I. Levi [22] V. N. Gontsharov and K. I. Rossinskyi were checked against observations data. From this comparison the theoretical results were found to be of an acceptable order of magnitude, to agree fairly well with each other, yet to yield values slightly higher than those actually observed. Miloradov, V. [7] in studying the sediment conditions of the Danube and its tributaries constructed the mathematical model for silting in the reservoirs by comparing 15 different formulae. These were found to be of a correct structure generally, but to require the determination of the necessary coefficients by field observations. It is further interesting to note that the correlation of the values ( v3 \ v log r? and log "3 1 h w> Yh^ involved in the method published by 1.1. Rossinskyi and I. A.Kouzmine was found to define an area bounded by straight lines, even in the case of the Danube, the upper range of which indicates degradation, while the lower one an aggradation of the bed. It should be noted in this context that entirely similar results were obtained earlier by S. H. Abalyanc [14] also, who defined the relationship between the quantities log U/ c and logy-R— Results of a similar nature were obtained also by us in the course of studies associated with the silting of irrigation canals in Hungary. On the basis of the results quoted above it is deemed permissible to believe that the semi-empirical formulae derived theoretically for sediment transporting capacity, and improved to allow for observation results obtained under particular field conditions, are reliable enough for estimating sedimentation, especially if the hydrological-statistical parameters of flow regime are also included besides the erosion conditions of the catchment area. 3. Estimation of sedimentation from empirical data During the hydrological dimensioning of reservoirs — and especially the smaller ones — the estimates on the useful life of the reservoir must be performed frequently in the absence of preliminary observation data. In similar cases the majority of the procedures described previously is either inapplicable at all, or the results will be very likely of questionable accuracy. Sedimentation estimates are therefore based expediently on more readily generalized hydrological considerations by establishing certain analogies for solving a particular problem. Relying on experience gained in Bulgaria the rate of sedimentation is described in the paper of Dr. Petshinov [8] by a relative annual sedi75
