Hidrológiai Közlöny 1971 (51. évfolyam)

1. szám - Dr. Öllős Géza: A kutak vízhozamát befolyásoló tényezők

Special Conference Number, Szebellédy, L. Hidrológiai Közlöny 1971. 1. sz. 25 of unit length is of decisive importance for the designer. The determination thereof — once the static approach is rejected — is a complícated task, since the inclusion of probability is alsó essential. It is therefore laudable that in the paper by I. Kontúr stochastic models of bank filtration water production are considered. The factors included are: — river stage, — river stage and water temperature, — the effect of infiltration due to river stage and precipitation on the potential yield. In the author's formulation a stage to be expected with a probability p is: H

p=H±U

pa

n where II the average stage, ah the other statistical characteristic of stage values: the standard deviation, U

p the multiplication factor pertaining to the probability p. If the yield of the bank filtration galery were the function of stage only, the probable volue p of yield which can be produced would be on the basis of the stochastic stage distribution: 3.2. Conservation area The aim of assigning a conservation area is to protect the water to be produced from impurities which may be detrimental to later uses. The organic, decomposable pollutants entering the water from the granular médium become mineralized along a certain path of seepage by biochemical oxidation. Higher concentrations of dissolved inorganic matter diminish by diffusion, mixing processes and the possible chemical reactions — once again over a certain seepage distance — to a concentration permissible for the contemplated uses. In the diffusion cone of "seepage" of organic or inorganic dissolved matter in the granular médium, characteristic for hydraulic conditions is that the concentration at the source of pollution diminishes in the main direction. The angle of inclination of the diffusion cone is influenced by the geometrical conditions, the kinematic characteristics of seepage, etc. of the soil — which is regarded as a médium. From the pubHcations of Kepinski, Nahrgang and Nemecek it becomes obvious that our knowledge concerning conservation areas must be developed on the basis of a process approach. Author has pointed out, that if the field of seepage or its contour-line are known (Fig. 17), then, for instance, in the case of oxidizing organic pollution, the introduction of the c

1 = constant, c

2= = constant, conservation area concept is alsó necessary. (In the figure the c

2>Cj condition is valid). In the light of this interpretation it can be ascertained that the pollution reaching the groundwater at point A interferes with water supply, whereas that at points B or C it does not. Of the papers submitted to the conference, that by A. Kepinski is devoted to the problems of conof seepage field. Well servation areas. The different pollutants, the selfpurification processes in the soil, the aim of conservation area zones, the aspects of selecting their dimensions are analyzed in detail. The paper provides a sound approach to further research work. 4. Conclusion The papers submitted to the Conference have dealt with practically every problem related to the production of water with the aid of wells. As reflected by the basic approach of the generál report, the filtration process associated with the wells presents a highly important part of water treatment technology. Due to their importance, attention sliould be paid to the details of technology: — a further analysis of the mechanical, chemical and biological processes involved, — the role and behaviour of the material of the aquifer, — the development of ambient factors in the aquiferous layer, the biological self-purification of the layer (especially concerning the possible extremes), — the role of the boundary seepage conditions, the possibility of influencing them, from the point of filtering, — the degree of eliminating different pollutants from the raw water (especially micro-pollutants, metallic ions, taste- and odour substances, mineral oil, hydrocarbons, etc.) — a periodie or constant decrease in the water quality and yield may be expected. The aim should be to determine parameters, with the aid of which the cause of these phenomena can be clarified, — it is essential to elaborate design criteria which may result in the eventual modificiation of treatment technology at waterworks, — in all research projects, after exploring the basic processes, the factors affecting the entire process should be considered on the basis of probability theory. Within this work, increased attention should be devoted to the role of hydrological factors.