Vízügyi Közlemények, 1969 (51. évfolyam)

4. füzet - Rövidebb közlemények és beszámolók

(11) H к — t lie volume of waler collectcd in reservoir к during the time increment j. (It is assumed that in the catchment area pertaining to the (n + l)-tli cross section there are altogether p reservoirs, numbered k= 1, 2, . . ., p.) 11' the budget computations according to Eqs. (1) and (2) are performed for all balance cross sections and for all time increments m the spalial and temporal distribution of available water resources and water deficiencies is obtained over the area considered, assuming that in the period envisaged (e.g. by the end of the perspective planning period) the assumed demands actually occur. Denoting over Ihe particular area the reservoir balance cross sections by serial numbers 1, 2, . . . , p and the non-reservoir sections by p + 1, p + 2, . . . , p + qu, the sum of balance results may be written in matrix form as B = (Bij)/ = l, 2, . . . , m; i = 1, 2, . . . , p, p + 1, . . . p + q. This matrix may serve as a starting basis lor determining the volume of contemplated reservoirs 1, 2, ... , p. Л method is presented for determining the optimum system of reservoir volumes by minimizing the costs of constructing the reservoirs and conveying the water to the users. The essential features of the method will be described below: a) An arbitrary numerical matrix A = (a

jk

I), j-i, 2, . . . ,m; k= 1, 2, . . . , p; ? = p + 1, p + 2,...,p + q is assumed, the elements of which satisfy the conditions of Eqs. (3) and (4), (see the Hungarian text) and where the cooperation factor cijia indicates the share of the water deficiency in section I and during the time interval j, to be covered from reservoir k. h

) It is assumed that releases from the reservoirs retarding sedimentation in them are made in the case of water shortages only and the rate of release is determined only by the cooperation factors and by Ihe magnitude of water shortages included in the matrix B. The reservoir volumes V„ V», . . . , V

p are computed from Ibis condition. c) The function К = A-j( V,) + Ы У

2) + • • • + Ap( Vp) + I) is determined, in which Ak(Vk) is representative of the relationship between the-total construction cost of the resevoir in section к and the reservoir volume V

k, while D is the cost of conveying water from the reservoir to the consumers. d) -Using a network, or Monte-Carlo method a great number of matrices A-i.e., a great number of different combinations of cooperation coefficients djki — is produced. For each matrix A the reservoir volumes and the correspmuling К function values arc computed. Eventually the system V,, V

2, ..., V

p adopted lor which the function К assumes minimum value. The application of the above water budget model is illustrated by a simplified numerical example. Since the method described for estimating the water budget and for selecting the optimum combination of reservoirs for meeting given water shortages is very laborious, the problem is preferably solved with the help of an electronic computer. Electronic compulation techniques, on the other hand, make possible the inclusion of factors neglected so far in the interest of simplification. These factors affect not only the results of the water budget, but also the further refinement of budgeting methods, 'the paper should therefore be regarded as a review of Ihe present stalus of investigations conducted continuously in Poland into the problems outlined here. Discussion on the paper "Contemporary problems of Ihe waterhousehold balance in Poland" by A. Philipkovsky. By Csermák, В., Civ. lingr., and Domokos, M., Civ. Engr. (Research Institute for \Yater Resources Management, Budapest.) Theoretical problems associated with w ater resources management have received relatively little attention in the literature. It is for this reason that regular exchange of experience has been initiated in 1906 between the Water Management Institute,