Vízügyi Közlemények, 1987 (69. évfolyam)

3. füzet - Domokos Miklós: A dinamikus vízgazdálkodási mérleg

A dinamikus vízgazdálkodási mérleg 449 The water management balance is an indispensable tool for the assessment of the state of water resources, in the planning and decision-making processes of their development. This relatively simple, crystal-clear and widely used method has been recently heavily critisized, in those past decades. Methodological development has been set to a halt at the same time. The author discusses first the classical, basic concepts of the dimensioning of water management systems that are similar to other engineering calculations e.g. in statics. These basic concepts are regarded as valid by him even for the future. According to these, the balance is active if the so-called "water restriction index" (y) - having the characteristics of a "stress" - does not reach the upper limit value of a so-called "limiting stress" (y*) calculated on the basis of economical, political and other considerations. If this condition would not hold, in other words if the balance is passive, then there is need for a row of technical, economical, and administrative inreferences to reestablish equilibrium of the water balance. The method of the static water balances - used earlier exclusively - called integrated water management balance that was attached to a "frozen" level in water resources development is also presented by the author. According to this method, one may consider the water demand either as constant or as a variable (in this latter case it is dependent - in rather different ways-on the water resources). Qualification of the water balances may be performed on the basis of relative duration in water restriction (y,

), or of the relative values of water deficit (y

2), (see Fig. 1); in case of most water uses the latter index was more advantegeously applied. In our practice, the y, index has been used rather exclusively. Qualification of water balances - if the water demand is variable - is shown in Figs. 2 and 3. Followingly, the introduction of a new "multi-stage water balance" is recommended by the author based for the time being on the static water balance, but lifting a restriction that was heavily critisized formerly allowing thus the simultaneous consideration of groups of water uses with different water deficit tolerances (Fig. 4). Finally, a dynamic water balance is theoretically introduced by the author in the framework of an attempted single, comprehensive simulation of several gradually changing water management levels - planned or forecasted - embracing the entire time horizon of long-term water management development. The basic idea of this method is the following: both the time-functions of usable water resources (K) and of water demands (I) are calculated depending on the development level (r), then one of the indices (y) of the integrated water balance is determined for each level (т). Finally, a critical index (y

cri

t) is selected from the distribution function of the у indices, and is compared to the prescribed upper limit (у*) of the same index by qualifying - in this way - the result of the water balance. * * * Die dynamische Wasserwirtschaftsbilanz von Dr.-Íny. Dipl.-Math. Miklós DOMOKOS Ungarn gehört zu den ersten Ländern der Welt, in welchen - infolge eines Zusammentreffens der Notwendigkeit und der Möglichkeiten - mit einer planmäßigen Bewirtschaftung der Wasserressourcen verhältnismäßig früh begonnen wurde. Die Wasserwirtschaftsbilanz stellt ein unentbehrliches Arbeitsmittel für die wasservorratswirtschaftliche Standaufnahme, Planung bzw. Entscheidungsbegründung dar. Die einfache, kristallisierte Methodik der Bilanz, die in weitem Kreise Anwendung gefunden hat, ist während des vergangenen Jahrzehntes mehrfach kritisiert worden. Dabei blieb eine Weiterentwicklung der Methodik völlig aus. Vorliegende Studie hat das Ziel, zu den theoretischen Grundlagen einer Verbesserung des gegenwärtigen Zustandes beizutragen. Im Interesse dessen wird in Kapitel 1 das - den sonstigen technischen, z. B. statischen Bemessungen ähnelnde klassische und auch für die Zukunft als maßgebend betrachtete Grundprinzip der wasservorratswirtschaftlichen Bemessungen kurz zusammengefaßt. Nach diesem Prinzip wird die Wasserwirtschaftsbilanz eines wasservorratswirtschaftli-