Vízügyi Közlemények, 1973 (55. évfolyam)

4. füzet - Rövidebb közlemények és beszámolók

(71) For estimating and predicting the available thermal water resources no sufficient data are as yet available. As an experiment the volumetric (geological) and statistical (empirical) methods of estimation have been used for predicting the thermal water volume which can safely be withdrawn. STUDY INTO THE DYNAMIC WATERLEVEL OF LAKES WITH SPECIAL REGARD TO LAKE BALATON By Dr. Duckstein, Dr. Ch. Kisiet and Dr. I. Bogárdi (For the Hungarian text see pp. 312) In connection with Lake Balaton a method is presented by which the probability distribution function of the dynamic water level in a lake, or reservoir can be determined. The dynamic water level is governed by two factors, namely the static level and the wind setup. The 60-year long record of the variations in static water level h(t) was used to determine ihe distribution functions thereof and this was found to fit well the normal distribution (Figs. 2 and 3). From group analyses it was concluded that monthly distribution functions can be classified into six groups. The wind generated rise in water level w(t) is composed of the setup h

s(t) and the wave height hu,(t). Observation data have shown both random variables to follow a normal distribution, so that the distribution function of their sum can be computed directly. The mean values and standard deviations of the monthly greatest wind generated rise in water level w(k) have been compiled in Table IV. For determining the optimum schedule of level control it is desirable to take into consideration the damages caused by dynamic water levels. In contrast to the monthly average damages related to the stationary water level X(t), the damage caused by the dynamic stage is represented by a single monthly value YH(t). With the help of the controlling variable Q(t) it is possible to compute from Eq.(5) the monthly stationary water level g(t). The highest dynamic water level H(t) in month t is obtained from Eq.(6). This value was found as the sum of two independent normal random variables. On the basis of the distribution functions of the dynamic stage it is possible to compare different water release policies and to select the optimum release schedule at which the economic losses resulting from the double uncertainty (changes in the stationary level and level rise due to wind) arc minimized. The nex stage of investigations was concerned with this problem in dynamic programming. The results thereof will be presented by the authors in a paper compiled for the 1973 Haifa Congress of IFAC International Federation for Automatic Control. ON THE LONG RANGE PLANNING OF REGIONAL WATER SUPPLY SYSTEMS PART II. THE PÉCS MODEL В Dr. Varga, József (For the Hungarian text see pp. 324) In Part I of the paper, published in No. 1, 1973 of the present journal, the formulation of a regional system model and the possibilities of estimating the model parameters have been described. Part II deals with the development of the original model, the organization of research work and presents a critical discussion of the results and shortcomings experienced there. The system model for the area bounded by the Danube and Dráva Rivers and the Mecsek Range was formulated first. The conditions and objective function of 8 Vízügyi Közlemények