Vízügyi Közlemények, 1967 (49. évfolyam)

4. füzet - Rövidebb közlemények és beszámolók

(4 3) Interrelations were studied by continued forced pumping from the so-called Zugló well and observing the changes of pressure conditions in other wells in the Pest area. The effect of extended increased withdrawal could not be analysed unless various factors influencing the karstic level, i.e. head have been cleared (Chapter 3). This was necessary in order to tell the effect of withdrawal apart from other influences. These factors are 1. the effect of recharge and natural drainage; 2. the effect of surface contour; 3. the effect of geology; 4. the effect of temperature of karstic water; 5. the effect of atmospheric pressure; 6. the effect of regime in the Danube River; and 7. the effect of artificial withdrawal. Changes of pressure in the observing wells during Lhe study are shown in Fig. 9, while the yield of the Zugló well has been plotted against time in Fig. 8 (Chapter 4). During the study period the well yield was increased artificially on two occasions (installation of a pressure vessel, drainage in two directions for reducing the resistance at the well head) and instead of the natural yield rate of 740 litres/min at free flowing conditions, the average pump discharge attained was 1750 litres/min. Forced pumping was continued for over 300 hours (Fig. 1) and its effect was detected and observed at the wells of the Dagály bath, well No. 2, Margitsziget, and wells No. 1 and 2, Városliget. The average reduction of head at these wells was 33,5 cm. Data were obtained on the propagation velocity of pressure waves as well (Fig. 11 ). The close interrelation between wells was demonstrated also by chemical analyses (Chapter 5). Data available and suitable for interpretation were used to construct the géothermie gradient map (Fig. 12). As to be seen therefrom, the iso-gradient lines show a star pattern elongated parallel to the fault lines, indicating thermal water rising along the faults. A further conclusion arrived at from the map is that according to information available at present, gradients differring from Lhe world average are restricted to relatively confined areas. Consequently, the thermal water resources stored in the karstic formations, which can be developed economically, are limited.