Piotr Moniewski
Geographical Studies, Issue 155, 2018, pp. 7 - 26
https://doi.org/10.4467/20833113PG.18.013.9536Discharge is one of the most important quantitative characteristics of springs. Not only does it specify the yield of groundwater, but it also reflects the water retention conditions of the aquifers. An analysis of the long-term spring discharge allows to link them to the hydrogeological and meteorological conditions of the area as well as to calculate the seasonal and multiannual variability parameters. The data from 84 springs in the south of Poland from the PIG-PIB databases were used in the paper. The time series differ in length and come from the period 1973–2016. The spring discharge variability index varies widely: from 2 to over 2 thousand, wherein the contribution of slightly variable, variable and highly variable springs is around 33%. The discharge of individual springs featured significant seasonal variations. Not only does the volume of outflowing water depend on the atmospheric conditions, but primarily on the properties of aquifer which feeds the spring’s groundwater catchment and on its location. The discharge of fissure springs as well as low-flow outflows is generally more variable than that of porous or karst springs. The seasonality of discharge depends less on the discharge of the spring and more on its elevation – springs which are at higher altitudes are characterized by a bigger seasonality index of discharge and a later date of its yearly peak discharge.