ZMIANY WYDAJNOŚCI ŹRÓDEŁ W WIERZCHOWISKACH W LATACH 1970–2012 (ROZTOCZE ZACHODNIE)

Abstract

CHANGES IN SPRING DISCHARGE IN WIERZCHOWISKA IN THE YEARS 1970–2012 (WESTERN ROZTOCZE)Abstract. The paper presents changes in the discharge rate of two spring complexes in Wierzchowiska, Western Roztocze, which give rise to the upper Sanna River. The study was based on own measurements of discharge carried out since 1970 and complemented with published data. The mean discharge rate calculated for over 190 measurements performed in 1959–2012 was 48.0 dm3· s-1 in the Dworskie springs and 128.7 dm3· s-1 in the Stoki spring. The changes in the discharge rate of both types of springs were comparable, with the dominance of a long-term rhythm. The reaction of the springs to recharge, likewise in the case of groundwater table in Roztocze, occurs after a long-term period of high or low atmospheric precipitation levels. On a monthly basis, no direct correlations were found between recharge and discharge of the springs. This was related to the slow rate of precipitation water flow through the thick aeration zone, the top part of which is represented by aeolian loess sediments.