prvi hrvatski speleološki kongres - KARST underground protection

The History of the speleological explorations in the catchment area of
underground rivers Reka and Ljubljanica, West Slovenia
Povijest speleoloških istraţivanja u porječju krških rijeka
Ljubljanica i Reka u zapadnoj Sloveniji
Andrej Mihevc 1
1
Karst Research Institute , Titov trg 2, 6230 Postojna, Slovenia; mihevc@zrc-sazu.si
Key words: podzemne rijeke, Reka, Ljubljanica, krš
Ključne riječi: Underground rivers, Reka, Ljubljanica, Karst
In Western part of Dinaric karst in Slovenia there are two from the point of
history of speleology important karst rivers: river Reka and river Ljubljanica.
Ljubljanica river is formed from a group of springs with discharge of the 38.6
m 3 s -1 at Vrhnika. Main part of the 1000 km 2 large catchment area is in karstified
rocks, with direct karst recharge. Part of the water does appear in springs on the edges
of four poljes, crosses them and sinks again. Part of the water is supplied also by
sinking rivers from noncarbonate rocks.
At springs and sinks several large cave systems were formed. Because of large
cave entrances, sinking rivers, springs and ponors and long lasting floods on the poljes
the area was in the focus of the interest of natural sciences long ago. Karst water
phenomena were first described in 17.th century. A. Kircher is giving underground
rivers from Cerknica polje as an example for his general theory on hydrophilacia. The
floods were later studied by J.V. Valvasor (1689), who also made some cave
exploration. Karst and caves were explored by F.A. Steinberg (1758), T. Gruber
(1781), and F. Nagel (1754). In 19.th century there is a large increase of the cave
exploration in the area especially after the discovery of the inner part of Postojnska
jama in 1818 (L. Ĉeĉ, J. Jeršinoviĉ, F.H. Hohenwart and F. Schafenrath,) and in
Planinska jama (A. Urbas, A. Schmidl). These explorations were connected with
touristic development and scientific interest in caves, cave biology, paleontology and
archeology (F. Hochstetter, J. Szombathy) in Postojnska jama, Planinska jama and
Kriţna jama. First cave animals were discovered and described. More difficult water
caves and deep pits were explored later in connection to hydro meliorations of karst
poljes (W. Putick).
In the second half of the 19.th speleological societies appeared. In Postojna
between years 1889 – 1905 caving society Anthron, and after year 1910 speleological
society from Ljubljana. After WW I the catchment area of the river was divided
among two countries, Yugoslavia and Italy. In Postojna was formed in 1927 Instituto
Italiano di Speleologia. Cave exploration and intensive work was done on the cave
register. In Ljubljana register of caves was established by Društvo za raziskovanje
podzemnih jam. After WW II new institute, Inštitut za raziskovanje krasa was
founded in Postojna. It works on the cave register and on more scientific karst
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