The Pivka intermittent lakes are unique hydrological system of 17 intermittent lakes of the Upper Pivka, of which nine occur more frequently and eight occur less frequently. On the basis of several years of field observation of 15 intermittent lakes and selected Pivka springs we explored their geomorphological characteristics and dynamics of lake formation in relation to hydrological conditions of the Pivka river and precipitation in the observation period. In the selected basins, especially those that are lake formed more frequently, we also explored the use of meadows and their threats. Results of the study revealed that the Pivka intermittent lakes are heterogeneous group of lakes which have a variety of karst inflows and outflows, as well as the number of them differs in each lake basin. Prestranek gauging station on the Pivka river is only partially a reference station for the dynamics of lake formation of intermittent lakes, which are complex hydrological system with different dynamics of lake formation between the lakes, which also applies to the lakes within both basic hydrological groups. Pivka has the most common features with Petelinjsko jezero, which is also the nearest lake to the gauging station. According to our own field data on the average annual duration of lake fomation for the period 2007%2010 Petelinjsko jezero is in the first place, followed by Parsko and Malo Zagorsko jezero. Among the intermittent lakes that are formed less frequently Jezero v Klenskem dolu is in the first place, followed by Jezero v Velikem dolu (za Kalcem), Bačko and Veliko Zagorsko jezero. Small lake basins are better managed with no overgrown land on the bottoms that are mowed fully with the exception of the present basin of Kalsko jezero with occasional grazing. In the discussion the comparative analysis of the intermittent lakes is given, as well as conservation of these lakes, among which 11 are protected in the Landscape park of the Pivka intermittent lakes by the Municipality of Pivka.
|
