Vízügyi Közlemények, 1999 (81. évfolyam)

2. füzet - Rövidebb tanulmányok, közlemények, beszámolók

328 Domokos Miklós Domokos M.: Az összesítő vízmérleg szempontjából mértékadó hónapok kiválasztása. Hidrológiai Közlöny, 1974/3-4. füzet. Domokos M

.: Az összesítő vízgazdálkodási mérleg mennyiségi oldalának elmélete. Vízügyi Közlemények, LXXI. évfolyam, 4. füzet. 1989. Domokos M.-Tarnóy A.: A felszíni vízkészletekkel való magyarországi gazdálkodás helyzete és reménybeli jövője. Hidrológiai Közlöny. 1993/6. füzet. ECE (Economic Commission for Europe): Manual for the compilation of balances of water resources and needs. United Nations, New York, 1974. OVH (Országos Vízügyi Hivatal): Országos Vízgazdálkodási Keretterv. Budapest, 1984. Tokámé Rudas J.: Számítási segédlet a vízhiányt mérő vízkorlátozási mutató meghatározására. Hidrológiai Közlöny, 1976/4. füzet. VGI (Vízgazdálkodási Intézet): Magyarország vizeinek műszaki-hidrológiai jellemzése. 1—9. kötet. Budapest, 1984-89. VT (Vízügyi Törvény): 1995. évi LVII. törvény a vízgazdálkodásról. Budapest. 1995. # * * Timely questions of utilizable water resources by Dr.-Eng. Dipl.-Math. Miklós DOMOKOS The most recent Water Act of Hungary (VT 1995) includes, among others, "the utilization of waters, the maintainance of this utilizability and the husbanding of water resources." Husbanding, however, is possible — at least on a certain risk level - only with known quantities. The coming into force of the new Water Act thus calls again for an exact, clean-cut definition of utilizable (available) water resources. The main statements of the Author in this respect are the following; — The notion of utilizable water resources cannot be separated from water resources management and the compilation of water management balances; it cannot be interpreted at all independently from the latter. — The time function of utilizable water resources of a closed catchment, Q

u,(t), is the algebraic sum of the time function of natural flow discharges leaving that catchment, Q(t), and those of a certain number of - deliberately selected - anthropogeneous balance-elements, ß*(0> according to Eq. (2) or (3). (The anthropogeneous elements not included among the components of Q

u,(t), will be the components - of course with opposite signs — of the balance arm called "water demand", Quit). — For founding water resources development decisions, i.e., for the qualification of the water management balance according to Eq. (1), the expectation value of one of the one- (Fig. 1) or two-dimensional indices of water shortage has to be determined. For this purpose, the time functions of utilizable water resources Q

u,(t) and of water demand, Q

D(t) (Fig. 2), have to be made available. From them, the value of the preferred index of water shortage can be derived directly, by simulation. — In the particular case when all anthropogeneous balance elements Q

k have constant values, thus only the natural discharge Q(t) fluctuates with time, the indices of water shortage can be determined also by adopting suitable formulae (e.g. Eq. (8) or (9)), without simulation, whenever knowing the probability distribution function of dicharges FQ(X), substituting equivaiently the time function Q(t) - or else its duration curve, equivalent with the latter or the duration surface, as well as the constant values of the anthropogenic balance elements, Q

k. This method, however, was of a certain importance only before the general expansion of computer technics, since the indices of water shortage can be determined of course di-