River with seven names - LJUBLJANICA - Retovje EarthCache

(SI) Ljubljanica predstavlja zaključek kraškega vodnega sistema. Geološki zaklad vas vabi k ogledu izvirov na koncu podzemnih poti kraških vodotokov.

PRED ZACETKOM:
Opis tega Geološkega zaklada je dolg. Prosimo, preberite ga in si zapisite naloge za vpis se pred obiskom zaklada!

NALOGE ZA VPIS OBISKA
1. Previsno skalno steno ob izviru Pod skalo v Retovju pogosto oblegajo plezalci. OCENITE njeno visino.
2. Zelo bomo veseli, ce kaksno zanimivo fotografijo z mesta zaklada prilozite svojemu vpisu (logu) obiska.

POMEMBNO!
- Preden vpisete obisk zaklada, posljite odgovore preko GC profila ali neposredno na e-naslov vane.si.geo@gmail.com. Takoj potem lahko vpisete obisk zaklada na spletu – ne potrebujete dodatnega dovoljenja. Ce ste fotografirali, prosimo, prilozite kaksno fotografijo.
- Vpisi brez ustrezne spremljajoce e-poste, ki vsebuje pravilne odgovore, bodo najprej trajno kodirani, kasneje izbrisani!
- Vpisi, ki vsebujejo odgovor bodo izbrisani!

(ENG) River Ljubljanica represents a final part of karstic water system. Earthcache invites you to visit sources at the end of its underground water course.

BEFORE THE BEGINNING:
This EarthCache has a long description! Please, read it and write down logging tasks before visiting the EarthCache site!

LOGGING TASKS
1. There are many climbers visiting the overhanging cliff at the POD SKALO source. ESTIMATE the height of the cliff.
2. We would be glad if you added interesting photos from the EarthCache location to your log.

IMPORTANT!
- Send answers through GC profile or directly to e-mail vane.si.geo@gmail.com
before logging. After that you can log - you don't need an additional permission to log. Please, upload photos if you have taken them.
- Logs without an accompanying e-mail containing correct answers will be encrypted and later deleted!
- Logs containing the answer will be deleted!

(ENG) River LJUBLJANICA flows through southern part of Ljubljana basin. It wells near Vrhnika, crosses Ljubljana moors, flows through Slovenian capital Ljubljana and into the river Sava, northeast of Ljubljana. It is supplied from many karstic underground streams. Its slow course from sources to confluence with river Sava, is only 41km long. But its river basin extends over 1779 square km, of which 1100 square km is karst. Ljubljanica karstic hinterland collects waters from higher valleys and plateaus interconnected with underground streams. Some of the streams can be seen in the water caves Golobina, Krizna, Karlovica, Zelska, Tkalca, Planina, Postojna, Predjama, Logarcek, Gradisnica and Najdena. Since the complete water course includes rivers wearing different names, it has been poetically named RIVER WITH SEVEN NAMES. These are:
1. TRBUHOVICA springs at Prezidsko polje in Croatia. High waters sink at Babno polje.
2. OBRH flows over Loz valley, sinks there and wells at Cerknica polje again.
3. STRZEN sinks at Cerknica polje, where also Cerkniscica flows from north and waters from Bloke plateau are added underground.
4. RAK flows through Rakov Skocjan, it has a confluence with river Pivka in Planina cave.
5. PIVKA flows over Pivka basin, through Postojna cave, it has confluence with river Rak in Planina cave.
6. UNICA is formed in Planina cave by confluence of rivers Pivka and Rak. It flows over Planinsko polje.
7. LJUBLJANICA wells near Vrhnika and flows into the river Sava near village Podgrad.

[Figure 1]

Spring Logascica could represent the eighth name. It collects underground water systems from Rovte region, Hotenje valley and Logatec polje. These waters join other earlier mentioned waters underground.
Ljubljanica is a part of Black Sea drainage basin, but some waters from Pivka basin and Hotenje valley flow to rivers Timav and Vipava underground and thus to Adriatic – not to Black Sea.

HISTORY
Ljubljanica has been a surface river in Tertiary - until circa 2,5 million years ago. The solubility of limestone in water and weak acid solutions has lead to formation of karst landscapes in Pleistocene. Surface water easily drains downward through joints in the limestone, and calcium-carbonate is carried away in solution. There is up to 250 milligrams of limestone in one liter of Ljubljanica water. Ljubljanica annual flow is about 1 million cubic meters, and therefore carries about 250 tons of limestone! This fact makes many karstic phenomena and underground streams more understandable.
River has been important traffic line since Roman town Emona has been established in the first century a.d. and until 1857 railroad took over almost all the cargo transports. Residents of Ljubljana have decided to drain the plain of Ljubljana moors, because of regular floods by the river, swampy and acidic soil of Ljubljana moors and unpleasant, frequent fog. To achieve this goal Grubar channel has been built in the 18th century, between Ljubljana castle hill and Golovec.

LJUBLJANICA SOURCES AT VRHINKA
Underground course of Ljubljanica ends at the southern edge of Ljubljana moors where it springs in many places.
1. Velika Ljubljanica springs in Retovje group of sources. These are: Pod orehom - Under Wallnut, Pod skalo – Under the Cliff, Malo okence – Little Window, Veliko okence – Big Window, Furlanove toplice – Furlan Hot Springs (constant temperature 23 deg.).
2. Mala Ljubljanica is formed by sources Veliki and Mali Mocilnik (Greater and smaller Mocilnik).
3. Bistra branch is formed by three springs on the Bistra monastery ground, Zupan spring near the road to Borovnica, Trebinja group, Pasji spring and Ribicev spring.
4. Ljubija branch springs at Verd in Gradar chasm, Smuk source, Ljubija and Ceglar brook.
5. Lintvern source.


[Figure 2] from book: Ivan Gams, Kras v Sloveniji v prostoru in casu, Zalozba ZRC, Slovenske akademije znanosti in umetnosti, Ljubljana, 2004

Those karstic springs are something special and well worth visiting! They show very different face in the time of high and low waters.

EARTHCACHE AND ACCESS
Earthcache is placed at Veliko okence – Big Window in Retovje source group. These sources are a great destination for a bicycle tour. You can also come by car through Vrhinka and village Mirke. Park your car at waypoint PARK1, at the end of the paved road. There is only a short walk upstream along the river to reach the wooden bridge across Velika Ljubljanica.
VELIKO OKENCE: Cross the bridge and turn right. There is a start of two trails there. The right one is a narrow path which leads along the river bed strait to the source. This path is NOT suitable for small children! We recommended the second trail for families. Wide forest trail leads south, slightly uphill, through the forest. It ends at gravel road which braches after just a few meters. Take the right road downwards. After 100m, at the lowest point, turn right to the forest path which will take you down, strait to Veliko okence.

[Figure 3] Veliko Okence in Retovje in the time of low waters

MALO OKENCE: Accessible easily in the dry season, otherwise NOT suitable for families or children!
POD SKALO is safely accessible any time. Just use wide trail at the other side of the bridge, following the river flow.
For a little longer hike, we suggest to park your car at waypoint PARK2, near Mocilnik. Visit Mocilnik sources first, then take a walk to village Mirke and Retovje sources.

Note: You use trails at your own risk. Use only trails you are fit to. Be safe and enjoy!
References: LIFE Nature 2006 project - Intermittent Lake Cerknica, Wikipedija, Photo: vane_si;

(SI) Reka LJUBLJANICA tece po juznem delu Ljubljanske kotline. Izvira v blizini Vrhnike, preci Ljubljansko barje, tece skozi mesto Ljubljana in se pri naselju Podgrad kot desni pritok izliva v reko Savo. Ljubljanica se napaja iz stevilnih kraskih ponikalnih voda v zaledju. Njen pocasni povrsinski tok od izvirov v blizini Vrhnike do izliva v Savo je dolg le 41 km. Vendar njeno celotno porecje do izliva v Savo obsega kar 1779 km?, od tega je kar 1100 km? porecja kraskega. Krasko zaledje izvirov Ljubljanice zajema vode visje lezecih podolij in planot, ki so povezane s ponikalnicami. Nekatere izmed njih so vidne tudi v vodnih jamah Golobina, Krizna jama, Karlovica, Zelske jame, Tkalca jama, Planinska jama, Postojnska jama, Predjama, Logarcek, Gradisnica in Najdena jama. Ker vodna pot obsega vecje stevilo poimensko razlicnih rek, je Ljubljanica pogosto poeticno poimenovana kot REKA SEDMIH IMEN. Ta so:
1. TRBUHOVICA izvira na Prezidskem polju na Hrvaskem, ob visokem vodostaju pa ponikne na Babnem polju.
2. OBRH tece po Loski dolini, kjer ponikne in se ponovno pojavi na Cerkniskem polju.
3. STRZEN ponikne na Cerkniskem polju, kamor se s severne strani steka se Cerkniscica, podzemno pa vode z Bloske planote.
4. RAK tece po Rakovem Škocjanu, v Planinski jami se zdruzi z reko Pivko.
5. PIVKA tece po Pivski kotlini, skozi Postojnsko jamo, v Planinski jami se zdruzi z reko Rak.
6. UNICA v Planinski jami nastane z zdruzitvijo reke Pivke in Raka; tece po Planinskem polju.
7. LJUBLJANICA izvira v okolici Vrhnike, v reko Savo se izliva pri kraju Podgrad.

[slika 1]

Osmo ime bi lahko predstavljal potok Logascica, ki deloma vkljucuje ponikalne sisteme obmocja Rovt, Hotenjskega podolja in Logaskega polja. Te ponikalnice se juzno od Vrhnike podzemno zdruzujejo s preostalimi zgoraj omenjenimi vodami.
Ceprav porecje Ljubljanice pripada sistemu crnomorskega povodja, se nekatere vode iz Pivske kotline in Hotenjskega podolja podzemno izlivajo tudi v reke Timava, Vipava in Idrijca ter s tem predstavljajo bifurkacijo crnomorsko-jadranskega razvodja.

ZGODOVINA
V terciarju je bil celotni tok Ljubljanice povrsinski, v pleistocenu pa je z zakrasevanjem zacela ponikati v poroznem apnencu. V litru vode reke Ljubljanice je raztopljenega do 250mg apnenca! Ker znasa letni pretok Ljubljanice priblizno 1 milijon m3 vode, torej vsako leto prinasa kar 250 ton apnenca! Ob tem dejstvu so podzemni tok in ostali kraski pojavi bolj razumljivi.
Reka je bila pomembna prometnica vse od ustanovitve rimske Emone (prvo stoletje nasega stetja), do izgradnje Juzne zeleznice leta 1857. Reka je Ljubljano pogosto poplavila, mocvirna in kisla barjanska zemlja ter pogosta meglena obdobja so Ljubljancane napeljale k nacrtnemu izsusevanju Barja. S tem namenom je bil v 18. stoletju zgrajen tudi Gruberjev prekop, ki je umescen v ozini med Ljubljanskim gradom in Golovcem.

POVIRJE LJUBLJANICE PRI VRHNIKI
Podzemski tokovi porecja Ljubljanice se koncajo na juznem obronku Ljubljanskega barja, kjer izvirajo na vec mestih:
1. Skupina izvirov Retovje tvori Veliko Ljubljanico: Pod Orehom, Pod skalo, Malo okence, Veliko okence, Furlanove toplice na Mirkah (temperatura vode je stalna, 23°C).
2. Skupina izvirov Mocilnik tvori Malo Ljubljanico: Veliki Mocilnik, Mali Mocilnik.
3. Izviri v Bistri se zdruzijo v povirni krak Bistra: Trije izviri v samostanskem obmocju, Zupanov izvir (skupina majhnih izvirov 100m ob cesti proti Borovnici), Trebinja ali Galetov izvir (skupina izvirov), Pasji studenec, Ribicev studenec.
4. Izviri na Verdu se zdruzijo v krak Ljubija: Gradarjevo brezno, Smukov izvir, Ljubija, Ceglarjev potok.
5. Izvir Lintvern.


[slika 2]

Ti kraski izviri so nekaj posebnega in vsekakor vredni ogleda! Pokazejo tudi zelo razlicen obraz med susnimi in mokrimi obdobji!

GEOLOŠKI ZAKLAD IN DOSTOP
Koordinate Geološkega zaklada so postavljene k izviru Veliko okence v Retovju. Skupina izvirov v Retovju je primerna za sprehod ali cilj kolesarskega izleta. V blizino se lahko pripeljete tudi z avtom skozi vas Mirke, parkirate na predlagani tocki PARK1, na koncu asfaltirane ceste. Od tod je ob reki kratek sprehod do lesenega mosticka cez strugo Velike Ljubljanice.
VELIKO OKENCE: Preckate mosticek in takoj zavijete desno. Tu se zacneta dve poti. Desna je ozka stezica, ki ob strugi vodi naravnost k izviru. Ta stezica NI primerna za majhne otroke. Za druzine predlagamo drugo pot. Široka gozdna pot vodi proti jugu, navzgor skozi gozd. Vzpne se do makadamske ceste, ki se ze po nekaj metrih razcepi. Izberete desni odcep, ki vodi navzdol. Po 100m, na najnizji tocki ceste, zavijte desno in po gozdni stezi navzdol, naravnost do Velikega okenca.

[slika 3] Veliko Okence v Retovju, v casu nizkih voda

MALO OKENCE: Enostavno dostopno ob strugi v susnem obdobju. Ob visjem vodostaju je stezica mestoma ozka in izpostavljena in NI primerna za male otroke! Druga pot pa je precej strma.
IZVIR POD SKALO je v vsakem vremenu varno dostopen po siroki poti na drugi strani mosticka, ob strugi navzdol.
Kdor zeli daljsi sprehod in se ogled izvirov v Mocilniku, naj avto pusti na parkirnem mestu pri gostiscu v Mocilniku, tocka PARK2. Od tam ob cesti vodi pespot proti vasi Mirke in cesta skozi vas do Retovja.

Opomba: Poti uporabljate na lastno odgovornost! Hodite le po poteh za katere ste ustrezno pripravljeni! Zelimo vam varno pot in veliko uzitkov!
Viri: Projekt LIFE Narava 06 - Presihajoce Cerknisko jezero, Wikipedija - prosta enciklopedija, Foto: vane_si;