Vízügyi Közlemények, 1965 (47. évfolyam)

4. füzet - Rövidebb közlemények és beszámolók

'(43) station Tiszakesz situated further downstream along the Tisza River. Water is conveyed and distributed to the plots by a network of elevated and deep canals branching off from the main canal. The total length of the conveying canals, with components shown in Table I, attains !)10 kms. Farmers' diversion total 504 in number and are detailed in Table II. The main purpose of the supplying system after full development will be to convey water to 144 000 hectares irrigation plots and fish ponds — of which approximately 49 000 hectares are in operation at present — as well as the diversion of l(i cu.m/sec — and from 1965 about 24 cu.m/sec water — to the Körös River in the south for the irrigation systems in the Körös Valley. Organization of operations is shown in Fig. 6, while the annual average personnel engaged is compiled according to functions in Table III. Operational activities of the irrigation system consisted in 1964 of providing and distributing 40 to 45 cu.m/sec water to 42 100 hectares irrigated land and to 5(i00 hectares fish ponds. Operation involves a twofold, namely watersupplying and technological function. The former comprises distribution of water to consumers, the second the tasks relating to diversion, control and management of water. Water is supplied at present according to a schedule compiled according to 5-day advance orders, but seasonal amounts are delivered according to contract to each consumer. A detailed account is given of administrative and actual implementation of water supply. The technological function in the majority of canals is based on downs/ream control with upstream checking, i. е., a method of water admittance where the waterlevel downstream of gates is maintained constant. On one of the major laterals of the system, the major lateral К. IV (Fig. 8), upstream control with constant upstream level was introduced with an experimental character. A detailed description is given hereafter of the implementation of individual phases of the technological function. The distribution of agricultural uses of water resulting from the operation activity described above, is presented in Tables V, V/, and VII according to crops, irrigation and supply methods. Operation costs and specific costs per unit area of water supply are illustrated in Fig. 16. The economic analysis of operation presents an as yet unsolved problem, so that no suitable evaluation can be given here. Summarized briefly the paper contains the following sections: In Chapter 1 a) the geographical location, b) the fundamental functions, c) the conveying network, d) the diversion of water to other systems are described,in Chapter 2 the organisation of operations, in Chapter 3 management of operations a) a general description of operations, b) the supply schedule and supplying function, c) the system of water provision and technological functions of operation are outlined. In Chapter 4 results of water supply and an operation analysis, while in Chapter -5 problems to be solved in further operation are presented. INVESTIGATIONS ON AN IRRIGATION MAIN CANAL FOR DETERMINING WATER LOSSES AND BED ROUGHNESS By Dr. '/.. Szigyártó, Engineer (For the Hungarian text see pp. 204) Investigations were carried out in the Great Hungarian Plain on the main canal of an irrigation section belonging to the system supplied from the Eastern Main Canal, in order to determine water losses and bed-roughness for improving operating conditions. Relying on results compiled in Table I it is established first that the determination of discharges entering and leaving the canal is not afflected by any regular error. It is demonstrated hereafter that the discharge in the canal, characterized by the profile and cross-section shown in Figs. 1 and 2, respectively, and built in cohesive clay soil, is increased at low stages by groundwater infiltrating from the environment (Fig. 3), while at stages maintained during irrigation seepage losses amount to about 350 1/sec. At the same time, relying on data presented in Table II it could be shown that the majority of this loss is concentrated to the reach downstream of section 13 + 001.