prvi hrvatski speleološki kongres - KARST underground protection

esearch, while cavers are organised in Jamarska zveza Slovenije which in
collaboration with institute builds the cave register.
First cave exploration in the catchment area of Ljubljanica was rather easy.
There were many large entrances and large easy passable caves beyond. The obstacles
were overrun according to available technique and knowledge. By the end of 19.th
century portable boats were used and deep caves to depth of 220 m were explored
with winches and ladders. Some digging and blasting were also involved. First diving
was done in 1930s, and main connections of the caves trough sumps were made after
1960.
Today main work is on searching for new entrances, enlarging the narrow
entrances or passages or diving in sumps. In the year 1983 there were 647 caves
known in the basin of Ljubljanica river. By the end of 2010 there are 1661. Mean
length of the cave is 82 m, depth 18 m. The total length of all cave passages is 136
km. But 10 the longest caves with total length is 66 km are all along underground
course of segments of Ljubljanica river or tributaries.
These caves are Postojnska jama, Kriţna jama, Karlovice, Planinska jama,
Najdena jama, Zelške jame, Logarĉek, Gašpinova jama, Tkalca jama and Dihalnik v
Grdem dolu.
The search for the galleries where Ljubljanica flows underground is the main
challenge for the cavers in the area. From the surface it was achieved only four times:
trough deep shafts of Gradišnica 1886, digging in the passage in Najdena jama in
1962, enlarging the entrance of the blowhole in cave Dihalnik v Grdem dolu in
(1992) and Vetrovna jama in 2002.
Reka is a surface river that sinks in the SE edge of 600 km 2 large Kras
plateau. At the ponor into Škocjanske jame cave mean annual discharge of river is 8.2
m 3 s -1 . After 35 km of the underground flow it appears at spring as river Timavo at the
coast of Adriatic Sea. River is now larger since it gets discharge from whole Kras
plateau.
The plateau and karst phenomena, specially sinking rivers and springs are
mentioned in antiquity already. First cave mentioned later is Vilenica, which was in
1613 already managed cave for tourism. Great part of the cave research was always
connected with water supply for Trieste and searching for the underground Reka river.
Systematic speleological research started in Labodnica in 1841 by Lindner and in
Škocjanske jame caves in 1839 by J. Svetina. It was followed by A. Schmidl and after
1884 by A. Hanke and J. Marinitsch from speleological section of DOAV alpine club
from Trieste. By 1889 the cave was explored till terminal sump.
Search for the underground river beyond Škocjanske jame followed. Many
caves were found and explored. After WW I the caves from the area were published
in monograph Duemila Grotte (1926) and Il Timavo (1938). At about the same time
the first diving attempts were made in the caves at the springs of Timavo.
Today the state border is dividing the Kras plateau so then data about caves
are collected by speleologists in Slovene and Italian cave registers. On the Kras
plateau above the underground Reka there are 2131 known caves. Total length of the
cave passages is 126 km, mean length 60 m, and mean depth 27 m.
The main discoveries, longest, deepest and most important caves in the area
are along the underground Reka. First to reach the underground flow of Reka were
A.F. Lindner and J. Svetina in the year 1841 in 329 m deep cave Labodnica or Grotta
di Trebiciano at Orlek. The cave was after that for 68 years the deepest cave of the
world. Next discovery of underground river was only in 1972 in Kaĉna jama, and then
cave is today 14 km long and 270 m deep.
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