Title Dinamika žala u području Kvarnera
Author Igor Ružić
Mentor Suzana Ilić (mentor)
Mentor Čedomir Benac (mentor)
Committee member Nevenka Ožanić (predsjednik povjerenstva)
Committee member Dalibor Carević (član povjerenstva)
Committee member Suzana Ilić (član povjerenstva)
Committee member Čedomir Benac (član povjerenstva)
Committee member Barbara Karleuša (član povjerenstva)
Granter University of Rijeka Faculty of Civil Engineering Rijeka
Defense date and country 2014-12-22, Croatia
Scientific / art field, discipline and subdiscipline TECHNICAL SCIENCES Civil Engineering
Universal decimal classification (UDC ) 55 - Geology. Meteorology. Hydrology
Abstract Osnovni cilj ovog doktorskog rada bio je izvršiti znanstvenu analizu dinamičkih procesa na minijaturnim šljunčanim žalima u području Kvarnera. Također potrebno je dati znanstveno objašnjenje pod kojim uvjetima su žala stabilna, odnosno pod kojim uvjetima dolazi do njihove erozije. Jedan od preduvjeta provođenja predviđenih istraživanja u sklopu ovog doktorskog rada bio je odabrati adekvatnu metodologiju za mjerenje složene trodimenzionalne topografije istraživanih minijaturnih šljunčanih žala. Odabrana je metoda Structure-from-Motion (SfM) fotogrametrije, odnosno primjena trodimenzionalnih oblaka točaka deriviranih iz niza fotografija zbog visoke razlučivosti i preciznosti. U radu su razvijene nove i prilagođene postojeće procedure za provođenje mjerenja i obrada morfoloških potaka minijaturnih šljunčanih žala. Prethodno je izvršeno preliminarno istraživanja više desetaka lokacija na obalama Liburnije, otoka Cresa i Krka. Nakon odabira najpovoljnijih i dovoljno različitih lokacija žala, detaljna „in situ“ mjerenja obavljena su na žalu Klančac kod Brseča, žalu Uboka (južno od Mošćeničke Drage), i na obali zapadno od Stare Baške (jugoistočna obala otoka Krka). Posebnost istraženih minijaturnih šljunčanih žala su izražene morfološke promjene izuvane djelovanjem valova na obalu. Obilježavaju ih značajne oscilacije volumena i rotacije tijela žala, u slučaju kada su izložena djelovanju valova iz različitog mjera. Značajne morfološke promjene minijaturnih žala nastaju prodorom slatkih voda kroz tijelo žala. Te promjene se očituju privremenom erozijom i brzim oporavkom žala. U provedenim istraživanjima zabilježene su oscilacije volumena sedimenta žala Klančac kod Brseča oko 30%, te žala Uboka oko 15%. Zabilježene su i značajne promjene oblika poprečnih presjeka žala. Ustanovljeno je različito hidrodinamičko ponašanje tijela žala Uboka i Klančac. Nakon olujnog vjetra iz sjeveroistočnog smjera na žali Uboka dolazi do potpunog oporavka tijela žala nakon erozije, prethodno prouzročene površinskim i podzemnim otjecanjem slatkih voda. Na žalu Klančac zabilježena je značajna erozija žala nakon olujnog sjeveroistočnog vjetra. Razlog suprotnoj reakciji dvaju žala je u različitoj zaštićenosti i orijentaciji uvala žala, izloženosti valovima i širini žala. Erozija žala Klančac nastaje brzo, djelovanjem najvećih valova sjeveroistočnog i jugoistočnog smjera, dok se oporavak žala sporo odvija tijekom umjerenih vjetrova iz južnog kvadranta. Istraživano područje pokraj Stare Baške karakteriziraju međusobno povezani procesi degradacije klifova i proširenja žala. U razdoblju od 1966 i 2004 zabilježeno je povlačenje klifova do 5 m, a obalna linja je napredovala do 7 m. Obalni klifovi izloženi su marinskoj eroziji. Na nožici klifa došlo je do formiranja potkapina klifa, koje determiniraju njihovu stabilnost. U radu je model stabilnosti obalnih klifova jednostavnih poprečnih presjeka zasnovan na konzolnoj gredi prilagođen klifovima složenih poprečnih presjeka snimljenih pomoću SfM fotogrametrije (Ružić i dr. 2014). U radu se pokazala važnost tijela žala u zaštiti klifova od marinske erozije
Abstract (bulgarian) The main aim of this PhD was to analize the processes and dynamics on pocket gravel
beaches in the Kvarner area of the Northern Adriatic. In particular, the focus was to
determine which conditions lead to stability and which lead to erosion of these
beaches.
One of the main pre-requisites of this work was to find a suitable method for
measuremnts of the complex three-dimenstional topography of pocket gravel beaches.
A method based on the Structure-from-Motion photogrammetry, which uses 3D cloud
of points derived from a series of photographs, was found to be the most suitable
method due to its high resolution and precision. New procedures were developed and
some existing procedures were adapted in order to take measurements and process
the data of the pocket beach morphology.
A choice of the most suitable locations to test the new method was made on the basis
of preliminary investigations at about ten different beaches on the Liburnia coast and
the islands of Cres and Krk. The detailed 'in situ' measuremetns were taken on the
Klančac beach near Brseč, Uboka beach (south of Mošćenička Draga) and on the
coast west of Stara Baška (on the southeastern coast of island Krk).
The distinct feature of these gravel beaches is that the changes in beach morphology
are caused by waves. This is demonstrated by the significant oscillation of beach
volumes and beach rotation due to successive waves arriving from different directions.
Significant changes in beach morphology are found also to be caused by a breach of
freshwater streams through the main body of a beach. These changes are expressed
in temporarily erosion and quick recovery. The measured oscillations in beach volumes
were 30% at Klančac near Brseč and about 15% at Uboka beach. These effects are
also observed in the beach profiles.
The hydrodynamic behaviour of the beaches at Uboka and Klančac are different.
Waves caused by southeasterly wind during storms help the recovery of the beach at
Uboka, which was breached by surface and subsurface freshwater. However waves
from the same direction cause significant erosion at the beach at Klančac. The reason
for these two different responses in the morphology of these two micro-locations are
their orientation towards prevailing winds and waves and the breaching due to
freshwater and in grain size. Erosion of the beach at Klančac due to highest
northeasterly and southeasterly waves is rapid, while recovery during modest southerly
waves takes much longer time.
The area studied near Stara Baška is characterised by the interaction between the cliff
degradation and the extension of the beach. In the period between 1966 and 2004,
the cliffs retreated about 5m while the shoreline advanced 7m. The cliffs are exposed
to marine erosion, leading to the formation of wave notches, which in turn affect the
cliff stability. In this thesis, a cantilever model for the stability of cliffs was developed
using a cross-section geometry developed from SfM photogrammetry (Ružić et al.
2014). This showed also importance of the beach in the protection of cliffs from marine
erosion.
Keywords
Minijaturno šljunčano žalo
Kvarner
Structure-from-Motion fotogrametrija
dinamika žala
rotacija žala
obalni klif
erozija
akumulacija
SWAN
Aladin
značajna visina vala
istjecanje
stabilnost žala
Keywords (english)
Gravel pocket beach
Kvarner
Structure-from-Motion photogrammetry
beach dynamics
beach rotation
coastal cliff
erosion
accumulation
SWAN
Aladin
significant wave height
discharge
beach stability
Language croatian
URN:NBN urn:nbn:hr:188:995767
Study programme Title: Civil Engineering; specializations in: Hydrotechnics and geotechnics, Mechanics Course: Hydrotechnics and geotechnics Study programme type: university Study level: postgraduate Academic / professional title: doktor/doktorica znanosti, područje tehničkih znanosti (doktor/doktorica znanosti, područje tehničkih znanosti)
Catalog URL https://libraries.uniri.hr/cgi-bin/unilib.cgi?form=D1130614014
Type of resource Text
Extent 183 str; 30 cm
File origin Born digital
Access conditions Open access
Terms of use
Created on 2017-01-19 17:12:25