Vízügyi Közlemények, 1965 (47. évfolyam)
4. füzet - Rövidebb közlemények és beszámolók
<120) Water resources development is defined as the activity by which water resources are utilized for the national economy as a whole and preserved in the interest of human life and activity. Water resources development cannot be regarded as a branch of hydraulic engineering only, as activities in all branches of the nation's economy are more or less affected thereby Г2]. Its scope and trend of development vary from country to country depending on natural, economic and social conditions prevailing there. Conditions for realization are most favourable in socialist countries with centralized executive power and controlled by an economic plan. However, neither in these has water resources development become institutional, and evolved its proper methods yet. The main reason for this lies in the differences of human attitude towards exploitation of conventional materials (e. g. mineral resources) and water. Water resources development is therefore compelled to evolve its own characteristic methods and tools. An important tool in water resources development is the waterbalance, for which the following generalized definition can be given: The waterbalance constitutes a systematic survey and comparison of available water resources and water demands to be satisfied therefrom, in a certain development unit during a given period. Water resources and demands are referred to as the arms of the water balance, these being formed by waterbalance items. The comparison of the arms of the waterbalance results in the waterbalance index. A mathematical approximation of the geneial definition of the waterbalance is also presented in the paper [6], and relying on the mathematical definition different forms of the waterbalance are established. Forms of the waterbalance used in Hungarian practice are as follows : 1. the total waterbalance, 2. the water resources development record and 3. the resources management profile. The resources management piofile is given a detailed study in Part II of the paper. The resources management profile of a watercourse is essentially a diagram indicating for any section the quantity and guality parameters of the arms of the total waterbalance and of selected items related to catchment area pertaining to the same section (Fig. 1). Five different types of resources management profile have been evolved in Hungarian practice. These are illustrated with the help of a simple example in Fig. 2. Individual types differ from each other 1. in the system of coordinates used and 2. in the grouping of waterbalance items. The coordinate system is determined by the section-line I (abscissae) and the axis of resources Q, for which latter a linear scale is used in every instance. The scale on the section line is, however, only in Types I, II, and III a linear one, in Types IV and V it is transformed according to the equation /* = — Q (I), where a is an arbitrary number, in order to obtain in the a coordinate system (/*, Q) obtained by transformation a single straight line for the expression Q(t*) (see Fig. 3 ). Different groupings of waterbalance items can most conveniently be demonstrated by listing the notations and relationships used in the paper. (This list is necessary for understanding the figures also.) Waterbalance items Qdi% = value of% duration (attained, or exceeded in% of the period considered) of the natural resources hydrograph. Qd y% = value of critical% duration of the natural resources hydrograph Qm = part of the natural resources which cannot be diverted from the bed Qn = Qd M% — Q m = reduced natural resources of d,% duration Qrs = Q<tu% — Qm = critical reduced natural resources
