Geomorfološko društvo Slovenije

Vljudno vas vabimo na predavanja v okviru Geomorfološkega društva Slovenije, ki bodo v torek, 18. decembra 2018 ob 17.00 uri v dvorani Zemljepisnega muzeja GIAM ZRC SAZU, Gosposka 16, Ljubljana.

Svoje študijske raziskave bodo predstavili predstavniki več slovenskih
fakultet:

• S. Stefanovski; Raziskave kopastega krasa v Sloveniji, Oddelek za geografijo, Filozofska fakulteta UL,
• K. Žagar; Geomorfološko kartiranje kvartarnih pobočnih sedimentov na območju Oseka v Vipavski dolini, Oddelek za geologijo, Naravoslovnotehniška fakulteta UL,
• M. Kostevc; Ocena ogroženosti naselja Belca pred drobirskim tokom, Oddelek za gozdarstvo, Biotehniška fakulteta UL.

Ob 18.15 uri pa bomo predvajali še dokumentarni film Blue Heart (https://www.youtube.com/watch?v=LadlBg9bmfg), ki obravnava ogroženost rek na Balkanu z vidika načrtov gradnje hidroelektrarn.

Kratki povzetki predavanj
Sašo Stefanovski, univ. dipl. geograf – Raziskave kopastega krasa v Sloveniji
Predstavljeni bodo rezultati raziskave kopastega krasa na štirih območjih s pomočjo DMVja in programskega orodja ArcMap. Izdelan je bil algoritem za zaznavanje kopastih vrhov in njihovih skupnnih baz. Nato so bile oblike klasificirane, kjer je bil cilj prav tako avtomatizacija postopka. Oblikam so bila dodeljena poljubna imena. Oblike so bile nato morfometricno analizirane, na terenu se je preverilo tudi ali se kopasti vrhovi pojavljajo na dolomitu, saj to v literaturi ni bilo omenjeno.

Kevin Žagar, dipl. inž. geologije – Geomorfološko kartiranje kvartarnih pobočnih sedimentov na območju Oseka v Vipavski dolini
V okviru diplomskega dela je bilo izvedeno geomorfološko kartiranje širše okolice vasi Osek, v Vipavski dolini. Pobočja severnega roba Vipavske doline so v veliki meri pokrita s kvartarnimi sedimenti, ki se
vključujejo v procese pobočnih premikanj in lahko tvorijo velike gravitacijske bloke. Ti bloki so morfološko zelo izraženi, z njihovim preučevanjem pa vedno bolje razumemo, kako so te geomorfološke oblike sploh nastale. Glavno temo diplomske naloge predstavlja analiza enega teh blokov.

Miha Kostevc, dipl. inž. gozdarstva – Ocena ogroženosti naselja Belca pred drobirskim tokom
Raziskava je bila izvedena na območju naselja Belca na Gorenjskem. Terensko delo je zajemalo snemanje (posnetki RGB) območja skalnega podora z uporabo brezpilotnega letalnika. V programu Pix4D Mapper je bil
izdelan oblak točk ter pravi ortofoto posnetek (TOF), v programu ArcMAP pa digitalni model reliefa (DMR). Na območju proženja je bila na podlagi posnetkov RGB ter TOF in DMR ocenjena potencialna količina podornega
gradiva (118.000 m3), ki se lahko še sprosti. Od tega, se lahko glede na rezultate modela r.avaflow v strugi hudournika Belca ob potencialnem podoru odloži 116.000 m3 podornega gradiva. Ta količina je bila v
nadaljevanju uporabljena kot vhodni podatek za izvedbo modeliranja drobirskega toka (r.avaflow). Pri modeliranju je bilo preverjenih 10 različnih scenarijev drobirskega toka (glede na volumsko koncentracijo
drobirja v toku in glede na količino sproženega gradiva). Rezultati kažejo, da obstaja možnost nadaljnjega proženja skalnega gradiva ter možnost nastanka drobirskega toka, ki lahko ogrozi naselje Belca.

Vabljeni na predavanje z naslovom Natural hazards in France: coping strategies in flood risk management, ki bo v ponedeljek, 20. avgusta 2018 ob 10.00 uri v dvorani Zemljepisnega muzeja GIAM ZRC SAZU, Gosposka 16, Ljubljana.

Predavala bo Jennifer Deriaz, ESAIP Engineering School, Angers, Francija.

Predavanje bo v angleškem jeziku (povzetek):
The objective of this talk is to give a global overview of the main natural hazards existing on the French territory. With a special focus on floods, it will describe some of the attempts to prevent these natural events from turning into disasters, through legislation, urban planning, increased public awareness and scientific research. The example of “épisodes cévenols”, violent and localized storms usually causing floods, will be used to illustrate the situation in the Eastern Mediterranean region of France.

Predavanje organizira Geomorfološko društvo Slovenije v sodelovanju z Geografskim inštitutom Antona Melika ZRC SAZU.

Vabljeni na predavanje z naslovom Tufa deposits sheltered by inland notches as indicators of Quaternary denudation rates, ki bo v četrtek, 31 maja 2018 ob 17.00 uri v dvorani Zemljepisnega muzeja GIAM ZRC SAZU, Gosposka 16, Ljubljana.

Predavala bo dr. Nurit Shtober-Zisu z Univerze v Haifi, Izrael.

Predavanje bo v angleškem jeziku (povzetek):
Inland notches are elongated concave-shape indentations that develop on the carbonate rocky cliffs of mountainous zones, down to the desert fringe. These unique features formed as a result of the interaction between specific lithological and climatic controls, emphasizing the importance of environment upon rock decay. The vast majority (71%) of inland notches in Israel are formed in hard, dense, and crystalline limestone deposited throughout the Turonian age. Another 27% are cut into the dolomitic sequence of the upper Albian and lower Cenomanian. The rest (2%) are dispersed in the various formations of the Cenomanian and Eocene eras. Inland notches form because of slight differences (1%–15%) in the porosity of the visor and cavity bed: the cavity bed is more porous, so more likely to erode by exfoliation and dissolution. Thus, the cavity bed retreats at a faster rate compared to the slower subaerial dissolution of the visor bed, until a critical point is reached where the visor collapses. In Israel, inland notches inhabit the same lithostratigraphic units as do large caves.

Notches are most common in semi-arid and in Mediterranean climates but mainly in areas with annual rainfall of between 400 mm and 850 mm. In more humid areas (> 900 mm/y) notches are negligible or completely absent, due to the rapid rate of chemical dissolution of carbonate rocks. In the desert fringe (200–300 mm/y), mechanical decay is accelerated and notches exhibit disintegration processes, visor collapse, and rock falls. In the desert area (< 200 mm/y), salt decay replaces the chemical decay, encouraging tafoni formation. In the Mediterranean zone, tufa stalactites and stalagmites occasionally grow within the cavity of the notch. In extremely rare cases they merge into columns, detached from the back wall. The tufa fill, both along the back wall of the notch and in detached stalagmites, is more typical of notches located on north-aspect slopes, which are characterized by a more hydric environment – that is colder, more humid and with a more stable microclimate. The Carmel tufa deposits that grew under the notches visors and on the cavity back-wall were dated by U-Th chronology at the Geological Survey of Israel using ion exchange column chemistry and MC-ICP-MS techniques. The ages were corrected for initial 230Th by using crustal average 232Th/238U atomic ratio of 4.2. In each notch the oldest tufa layer was dated giving the minimum age of the surface formation. Six layers from four tufa samples were dated giving ages spanning from 13,636 ± 834 ky to 37,562 ± 2,397 ky, implying that these notches were formed during the last glacial period, or during the last deglaciation.

Predavanje organizira Geomorfološko društvo Slovenije v sodelovanju z Geografskim inštitutom Antona Melika ZRC SAZU.