Identyfikacja okresów suszy hydrogeologicznej na podstawie obserwacji źródeł w Pienińskim Parku Narodowym (pieniński pas skałkowy) – wyniki wstępne

Abstract

The identification of hydrogeological droughts based on observations of springs located in the Pieniny National Park (Pieniny Klippen Belt) – preliminary results.A b s t r a c t . The paper discusses the results of stationary limnimetric observations conducted since 2003 for three springs located in Pieniny Czorsztyńskie within the Pieniny National Park. Current knowledge on the hydrogeological regime of the examined springs, and especially their response to precipitation, meltwater supply and type of discharge recession during periods with no water supply indicated that all the springs drained small local groundwater reservoirs characterized by rapid water exchange. One of the springswas of periodic nature. Relatively short (14 years) observational series on spring discharge were used to identify the periods of low flow and hydrogeological drought. In order to achieve this goal, total precipitation and snow cover thickness were analyzed in individual hydrological years. Low flow periods were defined as those when the spring discharge dropped below an average value calculated on the minimum annual spring discharge for the observation period. Identification of the hydrological drought was based on the interpretation of moving average values, which allowed for the elimination of changes in spring discharge due to seasonal fluctuations and random deviations. The basis for the determination of hydrogeological droughts were the deviations of moving average values from the mean value over the entire observation period. The methodology was similar to the ways of determining hydrogeological drought described by other authors in mountainous areas of Poland. Periods of the most severe hydrogeological drought in the Pieniny occurredin the 2003–2004, at the turn of 2005 and 2006, in 2012, and in the 2015–2016. Specific dates of drought occurrence for different springs were variable and depended on the morphological location of the spring and local hydrogeological conditions.