Ocena dynamiki drenażu wód podziemnych przez źródła pienińskie z wykorzystaniem głównej krzywej recesji (MRC)

The paper presents results of multiannual stationary observations carried out for three springs in the Pieniny National Park. Since 2003, two springs have been monitored, including automatic data registry, while the water states in the third spring were registered using DIVERs in 2013–2018. Appropriate consumption curves had to be constructed to convert the water states to their corresponding spring discharge. Their construction required direct measurements of spring discharges performed several times a year at different water states. Average monthly values were used in the analysis of the spring hydrogeological regimes, while average 24-h values were applied in the recession analysis. Changes in the spring discharge were analyzed compared to the sums of precipitation and snow depth. An analysis of 24-h series of changes in the spring discharge with regards to the precipitation indicated the source of the recession intervals for each spring, and they were then imported to the RC 4.0 software (HydroOffice, 2011) to generate the Master Recession Curves (MRC). The Maillet equation, which is most commonly applied in hydrogeological calculations, was used in the mathematical description of the curves. Recession coefficients (α) enabled the calculation of the storage capacity (W), which determines the groundwater volume accumulated in a groundwater reservoir during the enrichment interval and later regained due to spring drainage. The total amount of groundwater accumulated in the reservoir recharging the spring of the Pod Wysoki Dział stream (no. 1) is about 33,000 m3, the spring of the Kotłowy stream (no. 2) – less than 3,000 m3, and the spring of the Czarny stream (no. 3) – only 2,500 m3. The analyzed springs drain independent, small groundwater reservoirs characterized by distinct individuality, which means that each spring has its own specific hydrogeological regime.