PRESIHAJOCA JEZERA NA PIVSKEM 14 – BACKO JEZERO
INTERMITTENT LAKES IN THE PIVKA BASIN 14 – BACKO 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.
Severno od Baca lezi skupina stirih globeli. Ceprav se po velikosti med seboj opazno razlikujejo, jim je skupen strmejsi jugovzhodni del oboda - to lahko opazujemo tudi pri mnogih drugih jezerih. V največji globeli, z dnom na 560 m n.v., v letih z obilnimi padavinami nastaja Backo jezero. Njegova globina običajno ne preseže dveh metrov. Ostale tri manjše globeli lezijo vzhodno od Backega jezera, v ravni liniji JV-SZ in z nadmorskimi visinami dna na 570,2 m, 567,3 m in 565,9 m. V novembru 2000 so bile vse tri globeli poplavljene. Domacini pripovedujejo, da so v dolini, ki je vasi najblizja, nekoc gojili lan, zato jo imenujejo Laneno jezero. To je najvisje lezece jezero na Zgornji Pivki, zato je razumljivo, da je le izjemoma poplavljeno. Voda je leta 2000 segla do 572 m n.v. in se je po povrsju prelivala v sto metrov oddaljeno Backo jezero, kjer se je gladina dvignila na 568 m. Ob tem je zalilo se drugo manjso vrtaco na njegovem severovzhodnem robu in nastalo je jezero z enotno gladino. Prostornina (392551 m3) je tedaj kar za sestkrat presegla prostornino Backega jezera ob srednjem vodostaju. Severno od Backega jezera je voda zapolnila vrtaco in nastalo je manjse jezerce (4423 m2) z gladino vode na nadmorski visini 569,5 m in s prostornino 23631 m3.
To the north of Bac lies a group of four karst depressions. Although they are of markedly different size, they have one characteristic in common: a steep southeastern slope, which also exsist in many other depressions in Upper Pivka. In the largest of the four depressions (with its bottom at an elevation of 560 m asl), a lake called Backo jezero occurs after periods of heavy precipitation. Its depth usually does not exceed 2 m. The other three depressions, which are smaller, lie eastwards from the lake in a straight SE-NW line, with their bottoms at altitudes of 570.2 m, 567.3 m and 565.9 m respectively. In November 2000, all of them were flooded. According to local people, flax used to be grown in a doline closest to the village; hence the name of the lake which occurs in it – Laneno jezero (Flax Lake). This is the highest lake in Upper Pivka and therefore flooded only during exceptionally high waters. In November 2000, the water level reached an elevation of 572 m asl and the water was pouring into Backo jezero 100 m away where the water level rose to 568 m asl (Habic 2005). At the same time the lake flooded a nearby small doline on its northeastern edge and a single bigger lake was formed. At that time, the volume of Backo jezero (392551 m3) was six times the average. Northwards from Backo jezero, another doline was flooded and consequently a small lake was developed with its water level at 569.5 m asl, 4423 m2 in area and containing 23631 m3 of water.
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.