Vízügyi Közlemények, 1978 (60. évfolyam)

2. füzet - Kovács György: A síkvidéki vízrendezés és tározás alapelveinek korszerűsítése

A síkvidéki vízrendezés korszerűsítése 225 The substantial elements of the concept developed by careful analysis are as follows: — In semiarid plains, such as the Great Hungarian Plains, lowland drainage and irrigation form a system of water management activities which can be performed in combination only. In the interest of protecting the fields against the detrimental effects of salts accumulation, an effective drainage system is needed. The natural water supply to the plants is diminished thereby, necessitating the changeover in larger areas from dry- to irrigation farming. The introduction of irrigation farming, on the other hand, causes the rate of secondary soil deterioration to increase, which can be avoided by providing effective drainage simultaneously. — The most effective method of farm- and field drainage should be adopted with due regard to the particular soil conditions. Whichever method is adopted, the operating water level in the collecting canals should be envisaged at least 2.5 m below the average terrain level. Since lowering the water level in the entire existing drainage system would be uneconomical, the depressed collecting systems in the individual sub-catchments should be connected to the drainage principals by pumping stations. The optimal size of such sub-catchments is 10 to 15 thousand hectares with 20 to 25 thousand hectares forming the upper limit. — The existing shallow reservoirs for storing the drainage water are uneconomical, with poor efficiency and water quality parameters. These should be converted into deep reservoirs, in which the normal water level is high above the surrounding terrain, or similar reservoirs should be constructed in marsh areas of little agricultural value, feeding each reservoir by the pumping station of the drainage sub-catchment connected. As an alternative source the reservoirs should be supplied by river water as well, making quality control in them possible. Besides drainage and reservoir filling, the pumping stations could be used also for distributing the irrigation water. — In order to make the present irrigation development programmes feasible, about 17 thousand million Ft must be made available (at the 1977 price level) in each five-year plan period, starting with the sixth of Hungary, for reshaping drainage in combination with storage. In this manner protection can be afforded to the irrigated lands against secondary soil deterioration. The system of reservoirs and transfers contemplated can otherwise be extended to meet the irrigation water demands with the desirable degree of reliability. Should these sums exceed the funds available, the funds allocated for irrigation, the principal structures of water transfer and storage, as well as for plain-land drainage must redistributed in a way to permit these three interrelated activities, namely irrigation, plain-land drainage and plain-land storage, to be developed proportionately. — It is considered essential to reshape one, or two pilot sub-catcliments according to the concept outlined before at the earliest possible date, in practical preparation of the future work. * * * Modernisierung der Grundprinzipien (1er Gewässerregulierung und Speicherung in Flachlandgehieten von Dr. — Ing. György Kovács Die Studie analysiert die Wechselbeziehungen zwischen Gewässerregulierung und Bewässerung. Sie stellt fest, dass diese beiden Tätigkeiten nur zusammen, in gutem Einklang miteinander entwickelt werden können. Läuft nämlich einer der beiden Eingriffe voraus, verursacht das entweder eine schädliche Zunahme des Wasser- und Salzgehaltes im Boden, oder erhöht durch Entziehung des für die Pflanzen notwendigen Wassers die Dürregefahr. Die gleichzeitig durchgeführte Bodenfeuchteregelung muss mit der lokalen Speicherung des entzogenen und sodann von neuem zu verwenden gewünschten Wassers verbunden werden.