Vízügyi Közlemények, 1978 (60. évfolyam)
2. füzet - Kienitz Gábor: A vízminőség-védelemmel kapcsolatban jelentkező újabb vízrendezési feladatok
A vízminőség-védelem, vízrendezési feladatai 249 cause concern not only on account of their volume, but also because of their quality. These latter problems command attention, in spite of the inadequacy of observation data and experimental results alike. The purpose of this paper is arouse the professional public by inviting comments and starting discussions. Part 1 is devoted to the pollution aspects of the runoff volumes involved in reclamation-drainage, concluding that in contrast to the random character of pollution caused by industry and transportation, the use of chemicals in agriculture presents a steady source of potential pollution to the rain induced runoff. In Part 2 the theoretical-hydrological aspects of pollution in runoff waters are outlined. The possibility of determining that runoff volume L t is suggested, below which concentration is higher than the tolerated value and above which dilution is already sufficient to make concentration acceptable. In Part 3 the drainage strategy needed for pollution control purposes is considered. A classification is given a) for the pollutants reaching the water, b) for the potential hydrological-meteorological situations and c) for the sub-catchments as regards potential sources of pollution. The alternative methods of flow routing, namely channel storage, land storage and the addition of diluting water are examined for the case of a polluted discharge, by taking the foroegoing classification into consideration. In Part 4 a strategy is described for pollution control flow routing in the representative catchment Mirhó — Gyolcs situated along the upper reach of the Tisza River. The strategy is illustrated in Fig. 2. Two alternatives have been developed; according to the"first the polluted waters are retained in the sub-catchment where they originated, while in the second a common reservoir is envisaged for the entire catchment. The situations likely to develop under particular conditions have been examined. For the study an idealized form of the actual chemical use programme of 1976 has been assumed for the extreme hydrological situation of 1965. The chemicals used are shown in Table I, the last column of which indicates the runoff depth in mm units, which would have been needed to reduce concentration below the allowable value, assuming a leaching rate of one-thousandth for the chemicals. In Table II the concentrations at the runoff rates actually observed have been compiled (assuming a leaching rate of one-thousandth for end-winter runoff and one of 1% for summer runoff). The subject dealt with is summarized, conclusions arc arrived at and suggestions are made in Part 5. The use of chemicals is recognized to be a prerequisite of further agricultural development and this fact must be allowed for in reclamation-drainage work. Concerning practical solutions the joint responsibility of farmers, environment protection specialists and drainage-reclamation engineers is emphasized. The possibility of runoff waters being polluted by chemicals in the growing season must be taken into account. These must not be discharged into a recipient, but must be retained. The desirability of compiling strategies of pollution control and flow routing for each reclaimed area is suggested. The new tasks in reclamation-drainage raise to following major research problems: — Study of rainfall conditions in the growing season. — Starting observations for determining leaching rates for the chemicals commonly used in agriculture. — Development of a water quality observation system serving pollution control flow routing. — Promulgation of differentiated pollution control regulations, in which the need of using chemicals in agriculture is recognized, but the inevitability of some leaching is also taken into consideration. * * * 5 Vízügyi Közlemények
