Vízügyi Közlemények, 1969 (51. évfolyam)
4. füzet - Rövidebb közlemények és beszámolók
(12) Warsaw (Instytut Gospodarki Wodnej, ICW) and the Research Institute for Water Resources Development, Budapest (VITUKI). The author of the paper published, A. Philipkovslaj is head of the computer application section at the said Institute in Warsaw. The purpose of the discussion presented here is primarily to illustrate for Hungarian engineers interested in water resources management the relative merits of the Polish and Hungarian water balance models. It should be noted first that the water budget defined by Eqs. (1) and (2) in the paper by A. Philipkowsky is —in the Hungarian interpretation —a concrcte integrated water balance for the catchment area pertaining to the balance cross section (n + 1) and for the time interval j, the result Вц of which (the available water resources, or the water shortage) is obtained as the logical algebraic sum of balance elements characterized by individual numerical values. There is, naturally, complété substantial agreement between the Polish and Hungarian interpretations of the concrete integrated water balance. Formally, however, there arc certain differences (even beyond the differences in notations adopted for individual balance elements). It is obvious furthermore, that the matrix H involved in Section о of the paper by Philipkowsky is the counterpart of a water-balance combination, referred to in Hungarian practice as a "double balance scries". This budget model is applied by Philipkowski for dimensioning reservoir systems by economic optimization. (The method lends itself readily for generalization to complete water supply systems.) This method is new not only in Hungarian water resources management, but also on an international level. Its theoretical significance is left unimpaired by the fact that the cost functions (kb(V k),D) to be determined by economic analysis, and the existence of which must he assumed for making a solution possible, cannot be produced yet with the desired reliability. The greatest merit of the method of Philipkowsky is that it offers a theoretically exact, substantially clear solution for one of the main problems of water management activity, namely the design of water supply systems re-establishing the equilibrium of the water balance in an economically optimum manner. Even if difficulties would be encountered when attempting any concrete application, it is a welcome contribution to the formation of a conscious water resources management approach among the experts. In conclusion the writers submit suggestions for the refinement of the Polish water budget model. It would be preferable to complete the method by the shortagetolerance principle commonly accepted in Hungarian practice. In fact, one of the fundamental (implicit) assumptions of the Polish method is that the demands of the users must be met completely, i.e., not even temporary restrictions to the users can be tolerated. The combination V„ V.., ..., Г р representing the optimum reservoir system can be selected from among"the solutions only which meet the above condition. It will be readily appreciated that in general this will not be the optimum solution for the national economy. For obtaining a similar solution the actual magnitude of losses accruing to the national economy by water shortages must also be taken into consideration. Essentially it is suggested to include into'the investigation a matrix A = (a j ki) meeting not only the condition (1) but also a condition (4') and to design the reservoir system by minimizing function (5") rather than function (5). The inclusion of the suggested modification in the method would greatly increase the volume of required computations, since iL would call for the examination of a considerably increased number of matrices A. It is believed, however, that the increased computation work would present no practical difficulties in the electronic computation techniques required for the original solution as well. On the other hand, with the suggested modification the method would be more adjusted to practical requirements, and would be more complete theoretically.
