Vízügyi Közlemények, 1956 (38. évfolyam)

2. füzet - VII. Kisebb közlemények

(56) determination of floods of different recurrence interval with consideration of natural storage or steepness of slope different from the average. (The paper, and its French and Russian summaries were published in the 1955. Report of the Research Institute for Water Resources.) Finally Academican G. Mateescu (Romania) read a short paper on Hydrographie Service in the Romanian People's Republic From comments on the papers the following is pointed out : The iirst paper is helpful in planning surface water drainage schemes, because the heaviest burden on the drainage system of the Great Plain comes from snowmelt. Several research problems call still for solution in the storage of surface waters (control of drainage in extensive canal systems) and forecasting of surface waters in low iying areas. For the successful solution of hydrologie problems in connection with surface water control it is commendable : 1. To develop hydrographie observations on polders, 2. selecting polders for observations ; and 3. continuation of methodic research especially in forecasting surface waters. Dr. techn. W. Kresser (Austria) gave account of experiments with a tele-signaling snow densometer working with radio isotopes. On the basis of experience won last winter the instrument will be perfected and results will soon be published. In connection with the hgdrometrg of small streams the following was referred to : 1. Knowledge of low-discharges of small streams is very important in planning industrial water supply and sewerage or irrigation schemes. By good selection of permanent gauging profiles precise recording of tile change of local circumstances affecting flow dependable conclusion from water stages to discharges has to be secured. 2. From the point of view of observation the organization of posts of watchmen on natural streams (like those on canals) would be very helpful. 3. Sediment measurements should he introduced on small streams as well. 4. In the control of graphs elaborated for the computation of flood discharges data gathered by planning offices for the purpose of study shoidd also be made use of. Academician E. Alosongi pointed out that, besides measuring with radio isotopes, care should be taken that the growing use of radio isotopes may affect the purity of surface and of subsurface waters. The problem of contamination by radio isotopes has therefore also to be treated. V. Hydrographie Problems of Irrigation and of River Training The first paper of the session was read by University Lecturer E. Kertai on : Survey of Irrigation Water Resources (Full text, English and German summaries are published in this volume.) The subsequent paper was read by Prof. Dr. Ing. О. Dub, Corresponding Member of the Slovak Academy of Sc. on : Some methodic experiences won by the hydrologisl in the elaboration of the National Water Economy Plan The backbone of the Czechoslovak Water Economy Plan is the survey of water resources in space and time. Lack of data on streams insufficiently studied hydrographically have been supplemented by hydrologie analogy. Besides this, data of equal probability were computed by methods of mathematical statistics. Statistical parameters and different characteristic proportional numbers were plotted on longitudinal profiles and maps. The third paper was read by Gy. Kovács, Cand. of Eng. Sc., on Hydrographie Problems of River Training in Hungary Of hydrographie problems associated with river training the observation of flow of water is the most varied task. The laws of streams have first to be known in their natural state before studying changes caused by backup. In this connection the continnousdetermination of the surface slope of the stream calls for solution. On the discharge section of gently sloping tributaries the backup effect of the parent river is frequent. Data observed at that time can be used for the computation of backup curves. The suggested observations would be helpful — among others — in the implementation of forecasting in connection with the operation of sluice gates and hydraulic power stations. Comments on the papers may be summed up as follows :