Vízügyi Közlemények, 1970 (52. évfolyam)

4. füzet - Rövidebb közlemények és beszámolók

on the basis of observations performed for five years at the Spremberg reservoir on the Spree river. Scouring of the downstream bed was found to occur at a fairly uniform rate, practically unrelated to the mean discharge. Empirical relationships are introduced for changes of the rating curve and composition of bed material, as well as on mean sediment transportation rate and sediment take-up. The development of more accurate relationships has been prevented so far by the lack of an adequate number of data. Those observed so far may indicate no more than some of the potential trends of variation and continued measurements are felt necessary. * * * After the review of computation methods suggested for estimating the silting process of watercourses and lakes, it may be concluded that as a consequence of recent theoretical investigations and the generalization of practical observation data increasingly reliable data are obtained, which prove to be correct checked against subsequent observations. The theoretical solution of the problem may be formulated on the basis of Frankl's set of equations derived for the sediment transporting capacity of natural watercourses. Combining these with the dynamic equations expressing sediment equilibrium conditions and the dynamics of flow, further with suitable field observation data, an acceptable method of analysis is obtained. Nevertheless, in order to improve the reliability of results, in hydrodynamical solutions and empirical relationships alike, substantially greater significance should be attributed to erosion conditions over the catchment, the changes in sediment composition and especially to regime characteristics controlled by the hydrometeorological conditions over the catchment area. From this respect very great attention should be devoted to efforts at considering the reservoir together with the pertaining catchment area as a geological-hydrological unit and at investigating this combination as an undivided system. Quite obviously, the final solution of the problem, fully acceptable for all practical purposes and meeting the most exacting theoretical requirements would consist of the wider application of the techniques of systems analysis, the investigation of potential alternatives with the help of computer programs, and of the continuous refinement of results on the basis of practical experience. PAPERS REVIEWED IN THE REPORT 1. Bursali, S.: Investigation of factors affecting the efficiency of settling basins (in English) 2. Bogholjoubova., I. V.: Results of field observations and the estimation of sediment transportation on plain-land rivers (in Russian) 3. Dsharbashyan,E.T., Sanoyan,V.T. and Shamaghoryian, V. N.: Problems in the silting of mountain reservoirs (in Russian) 78