Yield Changes of the Niebieskie Źródła Springs - Their Reasons and Effects

The Niebieskie źródła Springs represent a unique site of the karst water type on the Polish Lowlands. Human intervention into the natural environment modyfied its surroundings and hydrological regime, changed output regression and even periodically caused total vanishing of the runoff. From among many reasons causing the above mentioned consequences borehole water extraction in Brzostówka opposite the Pilica river seems to be the most important one (fig. 1). However, considerations referring to output regression of the Niebieskie źródła Springs should not concentrate solelyon the nature reserve area because other factors, such as the conditions of ałimentation, circulation and drainage on the local scale should also be taken into account. Because the hydrodynamic balance had been upset as a result of water extraction in Brzostówka new water circulation ways were opened which enabled water runofT beyond the area drained by the karst springs. The recently started renovation and other works in the reserve area have gradually rebuilt water pressure but the real yield of the springs remained at a lower level oscillating around 60 l/s.Rezerwat przyrody Niebieskie Źródła stanowi jedyne w swoim rodzaju stanowisko wód krasowych na Niżu Polskim. W ich charakterystyce, opartej na wieloletnich obserwacjach, uwzględniono proces zasilania oraz czynniki regionalne i lokalne wpływające na ten proces. Wskazano na przyrodniczo uwarunkowaną cykliczność i antropologeniczne przyczyny regresji wydatku źródeł