PRESIHAJOCA JEZERA NA PIVSKEM 16 – KALSKO JEZERO
INTERMITTENT LAKES IN THE PIVKA BASIN 16 – KALSKO JEZERO
V pivski kotlini se nahaja 18 obicajno pojavljajocih se jezer. Proti severozahodu si sledijo Sembijsko jezero, Kalsko jezero, Laneno jezero, Backo jezero, Kljunov ribnik, Veliki dol (za Kalcem), Veliko in Malo Zagorsko jezero, Veliko in Malo Drskovsko jezero, Parsko jezero, Radohovsko jezero, Klenski dol, Palsko jezero, Petelinjsko jezero, Krajnikov dol in Jeredovce.
There are as many as 18 regular lakes in the Pivka basin. Towards the northwest the following lakes occur: Sembijsko jezero, Kalsko jezero, Laneno jezero, Backo jezero, Kljunov ribnik, Veliki dol (za Kalcem), Malo Zagorsko jezero, Veliko Zagorsko jezero, Veliko Drskovsko jezero, Malo Drskovsko jezero, Parsko jezero, Radohovsko jezero, Klenski dol, Palsko jezero, Petelinjsko jezero, Krajnikov dol and Jeredovce.
Pivka izvira v Pivscah, v odprti kraski globeli v blizini Zagorja. Ob dezju je tod vec izvirov v nadmorski visini med 551 in 554 m. Na jugovzhodnem robu globeli so izviri Videmscice, ki podzemno dobivajo vodo iz kraskega zaledja med Zagorjem, Knezakom in Bacem. V Videmscico podzemno priteka tudi voda iz Kneskih ponikev (Habic 1975). Malo pred izlitjem v Pivko doseze Videmscico umeten odvodni jarek, ki odvaja visoke vode iz bliznjega Kalskega jezera. Globel Kalskega jezera na vzhodem in juznem delu obroblja do 40 m visoko in dokaj strmo pobocje. Na uravnanem, osusenem jezerskem dnu (553,8 m) prevladujejo njive in travniki. Po podatkih s temeljnih topografskih nacrtov v merilu 1:5000 (TTN 1:5000) je srednji vodostaj Kalskega jezera na nadmorski visini 555 m, vendar pa se zaradi sprotnega odtekanja vode po odvodnem jarku jezero pojavlja izkljucno v manjsem predelu na severni strani globeli. Domnevamo, da je podatek o srednjem vodostaju se iz casa pred izkopom jarka. Ob izjemnih vodah novembra 2000 vodna gladina ni presegla 554,5 m, temu primerno je bila manjsa tudi povrsina jezera.
The Pivka river rises from the Pivsca karst spring situated in a shallow karst depression near the village of Zagorje. During high waters, several karst springs with elevations between 551 m and 554 m emerge in this area. Situated on the southeastern edge of the this depression are the Videmscica karst springs gathering water from the karst background in the vicinity of Zagorje, Knezak and Bac. Underground connections with the ponors near Knezak (Kneske ponikve) have been proved (Habic 1975). Near the confluence with the Pivka an artificial ditch, dug at the bottom of the nearby Kalsko jezero for land reclamation, reaches the Videmscica stream. The partly opened karst depression of Kalsko jezero, which lies to the southeast of Zagorje, is at its eastern and southern parts bounded with steep slopes (up to 40 m high). At its levelled and dry bottom (553.8 m asl) fields and meadows occur. According to 1:5000 scale basic topographic maps (BTM 1:5000) the mean water level of Kalsko jezero is at 555 m asl. However, since the water regime of the lake changed after a ditch dug into the bottom of the lake, flooding occurs in a small section in the northern part of the depression. It is presumed that the data on the mean water level originates from a time before the ditch was dug. In November 2000, during exceptionally high waters, the water level did not exceed 554.5 m asl and the surface area of the lake was accordingly smaller.
Vir / source: Gregor Kovacic & Spela Habic, Kraska presihajoca jezera Pivke (JZ Slovenija) ob visokih vodah novembra 2000 Intermittent karst lakes of Pivka basin (SW Slovenia)during high waters in november 2000, Acta carsologica, 34/3, 5, 619-649, Ljubljana, 2005