Vízügyi Közlemények, 1970 (52. évfolyam)

4. füzet - Rövidebb közlemények és beszámolók

(57) DIMENSIONING OF IRRIGATION STRUCTURES ON THE BASIS OF PLANT GROWING By Dr. J. Balogli, Agr. Engr. (For the Hungarian text see pp. 277) Part I of the paper comprising Chapters I and II lias been on pp. 180 to 202 published in the foregoing issue, No. 2, 1970, of the present journal. Part II of the paper, viz. Chapter III, appears in the present issue, No. 3, 1970, beginning with p. 277. The English abstract of the entire paper, combining Chapters I, II and III is found on pp. 30 — 31 of No. 2, 1970. DIMENSIONING REACHES IN DOWNSTREAM CONTROLLED IRRIGATION CANAL SYSTEMS By Dr. Kozák, M. and Dr. Szíggártó, Z. Civ. Engrs. (For the Hungarian text see pp. 288) At the Research Institute for Water Resources Development, Budapest, Hungary work has been started in 1963 with the aim of reviewing critically the design principles and operation techniques of irrigation water distribution systems, with special regard to canal networks. Suggestions were expected for improvement where necessary. The development of principles related to the design and operation of downstream controlled irrigation canal systems forms an uninterrupted continuation of this work, started at the above Institute in 1968. The first results of this study are reported in the present paper. In the introductory part of the paper the character of unsteady flow in Hie canals during downstream control operations is described with reference to Fig. 1. Relying on the conclusions arrived at by this analysis it is stated that the spacing of downstream control gates is controlled by the requirement that the lowest surface curve occurring as a result of flow variations during operation—tolerable with a certain risk —should not drop below the level which is critical for the operation of intake structures. Once the length of individual reaches is determined in this manner, principles arc given for estimating the permissible headwater level for individual intake structures. Mantle-type distributors (Table I), gated pipe culverts (Fig. 2) and the case where the intake is at the same time a downstream controlling sluice ( Fig. 3) are dealt with separately. Considerations are extended hereafter to the design discharges for individual reaches, setting the immediate research objectives and laying down the principles for computing unsteady flow phenomena related to the dimensioning of reaches. Concerning the practical performance of dimensioning a method is presented for determining the length of reaches and the method is illustrated by a practical example ( Fig. 4). The necessity lor further research work in this field is emphasized, with special interest to the determination of the characteristic vertical dimensions and elevations of intakes. In a few concluding complementary remarks the determination of reaches is pointed out in cases where some of Ihe fundamental data are unavailable, a method is given for designing safety structures and the problems still avaiting to be solved are summarized.