Vízügyi Közlemények, 1956 (38. évfolyam)

2. füzet - VII. Kisebb közlemények

(57) To the presented method o[ a assessment of the economically available resources of irrigation water I. Oroszlány (Institute for Research on Irrigation and Rice Farming) remarked that it has still to be refined in its details, first on the basis of more detailed regional agronomic plans, then by more precise consideration of water losses caused by seepage from canals. Protection against seepage is important not only from the point of view of economizing water resources, but because of the harmful rise of the groundwater table as well, which increases the danger of stagnant surface water and leads to marshland formation or secondary development of alcali soils. On the basis of investigation on seepage the irrigation method has to be chosen in a way that the amount of water supplied should only meet the requirements of vegetation. The determination of the economically utilizable irrigation water resources calls thus for the consideration of many contingencies. Others also drew attention to hydrologie research, and Prof. l>. A. Marchinkov (Bulgaria) suggested direct exchange of experience of the interested. The problem also arose, whether the planned transfer of water from the Danube would not call for addition to the low-water training works. Academician E. Mosonyi does not think a possible effect important, because water diversion will not be continuous. In context with the results of hydrological research in connection with the Czechoslovak Water Economy Plan Dr. W. Lászlóffy mentioned that they were in good harmony with Hungarian results. From among hydrographie problems of river training, problems of unsteady flow and of the influence of dams 011 sediment transport and thereby on the configuration of the channel were drawn attention to, which would call for morphological studies and model tests. R. Petrovic rendered account of extensive Yougoslav research 011 sediment transport and on protection against erosion. Further hydraulic and other observations on hydraulic constructions already executed were suggested as well as the establishment of a special shop for the instrumentation of hydrographie research. VI. Closing Session In the first part of the session M. F. Menkel, representative of the Academy of Sc. of the Soviet Union presented a paper jointly written with S. N. Kricki, D. Eng. Sc., on Some Theoretical Problems of Hydrologie design of Water Control Works For the survey of surface water resources the probability curves of annual water yield serve as a point of start. The standard probability (characterizing the probable time duration of full satisfaction of consumer demand) is fixed by regulations in the Soviet Union. For the hydrologie design of reservoirs and for the control of their dependable operation the authors elaborated in the 1930-ies methods of probability calculation. They plotted the results of theoretical investigations in graphs from which the necessary storage capacity can be directly read off, if the statistical characteristics of the stream flow regimen and the demand for water are known. The methods of probability calculation are also applicable to the operation of the reservoir. In the elaboration of instructions for reservoir operation, as far as possible, data of stream flow forecasting are also considered. Upon questions raised after the lecture l)r. Menkel told that investigations relative to the physically possible upper limit of the distribution curves have thus far nowhere led to an acceptable result. In connection with the modification of stream flow regimen and with the flood calculation formulae he pointed out thai in the different regions of the Soviet Union more and more hydrologie experimental catchment areas were being installed, on the basis of whose observations they hope to develop further the calculation method elaborated for natural drainage basins of small and of medium extension. The closing paper of the Congress was read by Academician E. Mosonyi, presiding, 011 : Hydrographie Cooperation in the Danube Basin He pointed out that 9 countries had their share of the drainage basin of the Danube of 820 000 sq. km. extension, and even the major tributaries crossed the area of several countries. Therefore the neighbouring countries depended in water economy, but more particularly in hydrographie research upon one another. From this follows the utility of closest cooperation in scientific research. Examining the possibilities of cooperation he made the following proposals : 1. Perfect exchange of publication among hydrological institutions of the Danube Basin. 2. Organization of national conferences to which hydrographie institutes and researchers of the other countries interested should be invited as far as possible. 3. Scientific institutes should think over whether it would be expedient to check against one another their more important measurements in order to compare a) in-