Vízügyi Közlemények, 1972 (54. évfolyam)

4. füzet - Rövidebb közlemények és beszámolók

(84) — detailed list of bench marks, map to 1:10 000 scale, — profiles to 1:200 000 and 1:100 000 scale, — cross-sections to 1:10 000 and 1:5 000 scale, — bridge cross-sections to 1:2 500 and 1:500 scale, — granulometric curves of bed-material samples. Information text is presented in three supplementary volumes. A separate volume is devoted to the hydrological, hydrographie and hydro-morphological data of the Danube, a novel feature in similar publications. The publication is very valuable as regards both contents and the metholodogy adopted. 2. Gerencsér, ArpácL, Mech. Engr., Uhereczky László, Electr. Engr. : The use of computers in complex water management in Japan (For the Hungarian text see pp. 453) The largest catchment area in Japan is the basin of the Tone River ( Fig. 1 ). Owing to widely fluctuating discharges storage is fundamental for irrigating 510 000 hectares cultivated area, but its importance in flood control and industrial water supply is also considerable. A regional plan for the deliberate management of resources has been prepared for the river basin, under which a number of projects have been realized, including the Tone and Akigase Dams, further the Ora-, Saitmaand Asaka Canals. The canal system is upstream controlled, control being provided by a computer (Figs. 5 and 6). The programs are fed in FORTRAN language to the central FACOM 270 — 20 type computer. The flow of water is controlled by an appropriate system of gates and measuring devices. Signals are transmitted in the ultra short- and micro wave bands. Water levels within the system are controlled to ±2 cm accuracy. 3. Gasser, M. M., Civ. Engr. and Ujfaludi, László, Physicist: Seepage resistance in earth dams and flood levees (For the Hungarian text see pp. 466) Hele-Shaw- and hydraulic sand model tests have been performed for clearing some problems related to seepage phenomena in earth dams and flood levees. The influence of foundation thickness and base width of the dam on the downstream exit height has been examined together with the phenomenon of hydraulic soil failure at the downstream slope for the case of cohesionless soils. It was again concluded that within the range considered the thickness of the permeable foundation layer is of little influence on the height of emergence of the phreatic surface, whereas the height of emergence was found to decrease as the base width was increased. As confirmed by the experiments, hydraulic soil failure started with the displacement of individual soil particles. The critical stage increased for coarser soil particles and decreased for greater base widths. The stability of the dam could be improved appreciably by a carefully dimensioned filter layer on the downstream slope, in that it prevented the soil particles from becoming eroded. <5. Fehér, Ferenc, Civ. Engr.: Hydraulic model of mole drains in cohesive soils (For the Hungarian text see pp.* 472) One potential method of meliorating the cohesive soils with poor waterhouseliold characteristics in the hilly parts of Hungary consists of constructing mole drains. After the exploration of hydrological conditions a hydraulic model has been conceived for studying the complex mole drain system. The hydraulic model consists of the mathematical system comprising the loosened till layer, the mole drains and the filtered drain ditch. The conveying capacity and flow in each element has been described by mathematical expressions. In this way it is possible to calculate the capacity of the entire model, as well as the spacing of drains. The expressions describing idividual elements of the system lend themselves for calculating various parameters. The determination of the permeability coefficient of the tilled soil layer and of tte filter layer in the drain ditch is of special importance.