Hidrológiai Közlöny 1949 (29. évfolyam)

9-10. szám - Értekezések - J. BOGÁRDI, D. Eng.: Report on the Ground Water Conditions of the Great Hungarian Plain

up, but even more numerous are the wells which were damaged and became uselles dnring the recent war. The well network under the management of the Institute consists of 412 pipe wells part of which can he put in operation again after slight or more serions repairs. The stages in the wells are measured ten times a month or in the average every third day. alwavs downwards from the precisely leveled hrim of the well. Thus every stage sboAvs therefore the depth of the water table below the brim of the well. The orosraphical development of the Carpathian basin exnresses already the hydrogranhic unity of the region. Tbe hydroaraphic unítv concerns of course alsó the ground water conditions which is verified by the similar character of variation of the ground water le,vei áll over the country. Characteristic of tbe .pround water level variation of tbe Alföld is that at the end of the spring (March, April. Ma-" or r>erhar»s Jnne) are the maximums, and in the fali íSentember. October and November) are the minirnums. shr<winn the continental chnm^ter of the ground water variations of the. AlföldOn aor'ount of tbe climatic conditions of the Alföld, tbe relatively long and inclement winter nrevents the sunolv of the ground waW. The precipi tation in form snow cannot infiltrate in the frozen ground. The supplementing of tbe ground water can start at tbe beginning of the meltin<r onlv. resulting through freonent fa«t melting the highest staeres in the months of the spring. In the summer the increased evanoratiou. tbe water consumntion of the nlants and not least, the eeneral aridity steadily lowers tbe water table which culminates in the fali in the lowest nosition. The rains at the be<íinning of the fali and winter raise asain to somé extent the, water table, and depending on the inclemency or the mildness of the winter. turns in the melting period in a comparatively bigber level. Figure 2. represents the variations of the ground water wells at Kiskunhalas— Harkapussta and Püspökladány for the hydrologic years of 1942, 1943 and 1944. (Location of the wells may be found on Figure 8.) The well at Püspökladány is characteristic of the even ferritory of the transTisza while Ihat at Kiskunhalas of the territory between the Danube and the Tisza. It is most peculiar that at the trans-Tisza well the water table was considerably lower below the ground Fig. 2. ábra. Fig. 3. ábra. Duration curve. During the decaile of XI. 7. 1937—X. 31. 1917. Tartóisági gwrbo 1937 XI. 1^1947 X. 31. level than that of - the well of the territory between the Danube and the Tisza. This circumstance is generally characteristic of the ground water conditions of the two régions. In the case of the two examined wells, the spring maximums were by 140 cm to 180 cm, the fali minirnums by 190 cm to 210 cm lower at Püspök ladány than those at Kiskunhalas. Among the above three years, 1942 was very rainy and cool, 1943 was exceptionally poor of precipitation and hot, while 1944 could be cons'dered a year of average climatic. conditions. This circumstance is decisively manifested in the ground water stages of the respective years. In rainv years the minimum anteceded bv the maximum at Kiskunhalas sbows a stage of less than 160 cm while that at Püspökladány sbows less than 200 cm. As a whole similar stage differences prevail belween annual minimum of the arid year and the maximum of the following averaee year. In an arid year the differencies between the maximum of the spring and the minimum of the fali are considerably smaller tban the fore?oing values. Thus, for instance. thev are at Kiskunhalas about 80 cm, and at Püspökladány about 120 cm. The annual mean stasre in a rainy vear is at Kiskunhalas bv 40 to 60 cm. and at Püspökladány by 60 to 90 cm higher than in the average years- Whilo a dry year compared with an average year shows a difference at Kiskunhalas of 20 to 40 cm and at Püspökladány of 40 to 80 cm. As a result ít anpears that the ground water stages at Kiskunhalas and at Püspökladány with their soring maximums and their fali minirnums show that the ground water conditions of the Alföld are continental. On both wells the variations of tbe ground water stages, considering the division of Ijiász. are characteristic of the soealled ground water type fed by infiltration. It must be mentioned that in viewing the ground water conditions on the Alföld besides the average and deep normál types the forest type. the type fed by rainfall, the type developing from hydrostatic pressure, and the indisturbed type must alsó be taken into consideration. Figure 3 represents the 10 years duration of the examined ground water wells. The ten years taken into consideration, extending from November 1, 1937 to October 31, 1947, conside.279