Vízügyi Közlemények, 1969 (51. évfolyam)

4. füzet - Rövidebb közlemények és beszámolók

(106) soil mechanical, etc. properties of the levee. As a consequence thereof the required degree of protection could not be attained in certain places, whereas over other sections reinforcement was unwarranted. When considering physical factors (ageing of the levee, soil stratification, wave action, ice conditions, etc.) a "safety freeboard" should be estimated for each of them. Using the method suggested the lowest degree of protection x' required for attaining the development specified can be determined together with the sections along the levee under consideration where detailed designing is required for improving the original degree of protection to the value x'. Along the sections where the original degree of protection is higher than x', no reinforcement is necessary. Once the construction costs for a particular development have been estimated, the costs for any other degree of development can be found by simple proportionality. This method may be considered as the fundamental aid of optimization for individual sub-catchment areas. BRIEF PUBLICATIONS AND REPORTS 1. Vincze, O.: Problems faciiu) the Swiss Water Management Association. (For the Hungarian text see pp. 513.) Timely problems of water management have been discussed on the 1968 conference in Locarno of the Swiss Water Management Association (Schweizerischer Wasserwirtschaftsverband). The following problems have been dealt with: Changeover from hydroelectric to nuclear power, pollution control of natural waters, the role of subsurface waters in water supply and the economic aspects of inland navigation. The opinions and conclusions voiced at the conference are of great significance in the development of a water management policy, since the general trends in water resources development are reflected in them. This significance is apparent also in Hungary, although the conditions here are fundamentally different from those in Switzerland as far as water management is concerned. 2. Némethij, L. Civ. Eng. : Determination of a numerical rating curve by nonlinear interpolation. (For the Hungarian text see pp. 516.) Insolving certain problems in water management new values must be interpolated between existing function values, but owing to the character of the function, or to the distance of the two points no linear interpolation is permissible. Interpolation according to polynoms of a higher order must be resorted to in such cases, where the function between the two specified points is replaced by a polynom rather than by a straight line. As an example the estimation of the numerical rating curve (Table I) for a composite channel (Fig. 1.) is described. Intermediate values are more readily obtained by interpolation than by direct computation. In other cases the procedure can be used to replace even more complicated computation work. 3. Vihar, L. Civ. Eng. : Deep foundations by the diaphragm-wall method. (For the Hungarian text see pp. 521.) Among the foundation methods introduced recently in Hungary the one using diaphragm walls is the latest. A licençe has been purchased from the Italian firm Titania by the Hydraulic Construction Firm, Budapest, according to which Titaniatype excavators are manufactured and diaphragm walls are constructed either by the inverse-flushing rotary method, or by a grab attachment. The technology used for the former is shown in Fig. 2., while that for the latter in Fig. 4. Diaphragm walls have been constructed also with the French Poclain excavator (Fig. 5). In 1969 altogether 36.300 sq. m diaphragm wall will be constructed. 4. Dr. Szabó, L. Civ. Eng. : Utilization of the Wizna-marsh in Poland. (For the Hungarian text see pp. 524.) The first efforts at the efficient utilization of marsh areas in Poland have been made more than one decade ago. Of these the reclamation of the Wizna marsh (District Bialystok) is decribed as an outstanding example. The marsh area reclaimed is described first (Fig. 1 ). About 17.000 hectares were periodically inundated, marshy