Hidrológiai Közlöny 2003 (83. évfolyam)
6. szám - Havassy András–Papp Szabolcs: Nem-karsztos hegységi források átlagos vízhozamának meghatározása – a mérésszám csökkentés lehetőségei (angol nyelven)
354 HIDROLÓGI A] K. ÖZ LÓ NY 2003. 83. ÉVF . 6. SZ. The amount of processed data This graph shows the data, belonging to given days that we used for our calculations. Most of the springs were measured between February and November, data from January and December are very unfrequent, that is why average and standard deviation values for this period of time we disregarded in our evaluation (Figure 4.a, b.). Fig. 4. a (4. a ábra) The number of processed data belonging to calendar dates in the row of date of Tokaji Mountain springs A naptári napokhoz tartozó, feldolgozott adatok száma a tokajihegysigi források adatsorában -íKKíssíssBSRSisStSSRsnnsRjjájiíSsgjjSjjjj Fig. 4. b (4. b ábra) The number of processed data belonging to calendar dates in the row of date of Börzsöny Mountain springs A naptári napokhoz tartozó, feldolgozott adatok száma a börzsönyhegységi források adatsorában 4. Evaluation Comparing the the two mountains' rows of data it is outstanding, that the flow of Börzsöny Mountains' springs is much more even, and we can count for less than 20 % measuring imperfection most of the year. The flow of the Tokaji Mountains' springs is a lot less even, but there are relatively long periods when we can count on less then 20 % imperfection in measuring. According to our calculations the values of yield, closest to the yearly average can be measured in both mountains about the same time, with little difference in time (Chart 2, 3). We found its reasons as followes. The flow of descending springs in non-carstic mountains is basically determined by the amount and temporal dispersion of precipitation. The growth of yield of springs starts with the melting of snow. It is when the flow graph crosses the staright line of the average for he first time, from below (Figure 1 .a, b). The starting time of melting is influenced by the geographical location, hight and exposition conditions. The filling up of water-bearing rocks and the increase of spring yields depends on the speed of melting. In case of slow melting at first the pores and fissures of rocks get filled and the spring yield increases significantly only after reaching a sufficient subsurface water level. In case of quick melting, when the scale of infiltration can not keep pace with the speed of melting, the amount of surplus water soon appears in the springs. So the flow graph's biggest, spring maximum is the result of more months' precipitation, stored in the form of snow. The majority of the yearly yield of springs comes from the melt water. Further significant water supply may come from heavy rains, but only in that case, if a part of water-bearing rocks gets empty on the cathment area of the spring by that time. The summer rainstorms temporarily increase the yield of springs, but their water quickly runs away in the loose sediments. From the second part of the summer the amount of yield reduces until the following melting season. It is when the second point of intersection forms (Figure 1 .a, b.). The reducing yield is at first the result of summer drought, then the lack of water caused by the precipitation turning into snow with the beginning of the frost. The autumn precipitation can result in a temporary increase of the yield, producing further points of intersection on the flow graph. Those springs, of which intake area gets empty dry out, but the other springs' yield reduces as well. The yield of ascending springs is much more balanced than that of the descending ones, but we can observe the influence of precipitation there too. It is characteristic of their flow graph (depending on the size of the suffice catchment area) that we can observe the maximum, caused by the spring melting, but after this period a generally even yield settles and it remains characteristic until the following melting season. Another conclusion that can be drawn from the above mentioned facts is that our method is effective only restrictively. The starting time of melting changes from year to year, consequently the point of time, when the flow graph intersects the yearly average's line (when the difference between them is zero) alters also. However we believe, that a further research sequence can be based on our method, in the range of which regular measuring of properly selected springs during several years would provide us with a general picture of the flow of smaller territories' (mountains, catchment areas) springs, and subsequently the number of measurements can be reduced, taking into account the points of times established with our calculations. We regard the following procedure as one of the possible applications of this method. On a chosen territory we measure some of the springs monthly, and the rest of the springs in the most suitable few points of time, that were determined on the basis of many years average. In the end of the year from the flow of the regularly measured springs we can determine the most suitable times for measuring that year as well as the average flow, and from this we can calculate the degree of accuracy (%) of average yield of the springs with only a few measure data. We emphasize once more in conclusion, that the most accurate results would stem from the monthly measurings from each spring, and we regard our method as a way of looking for the least inadequate method under constraints. Bibliography Izápy G. - Maucha L et aL (1996): Magyarország nemkarsztos hegyvidéki területeinek felszín alatti vizeivel kapcsolatos problémák megoldását megalapozó vizsgálatok. VITUKI Hidrológiai Intézet Zárójelentés. Budapest. 36 p. IzápyC. (szerk.) (1999): Magyarország forrásainak katasztere III. - IV. Börzsöny, Zempléni-hg. VITUKI Rt. Törvény a természet védelméről (1996. évi Lili törvény). Magyar Közlöny, 53. 3325-3346 A kézirat beérkezett: 2003. április 12.
