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Gravel beaches provide natural coastal protection along other ecosystem services to many coastal areas. By dissipating wave energy, they can contribute to stability of cliffs and coastal structures behind them. This paper investigates the effectiveness of gravel pocket beaches (GPB) for protecting urban coastline in the city of Rijeka, Croatia. Two beach systems were studied, a natural system comprised of a beach and a cliff (Sablićevo) and a man-made system (Ploče) comprised of an artificial beach and a sea wall. The rocky coastline around Rijeka is predominantly formed in carbonates (Benac et al., 2013). A number of pocket gravel beaches can be found at locations of previously weakened carbonates, where a local erosion of coastal cliffs provides the sediment supply (Pikelj and Juračić, 2013). This is a micro-tidal environment with a tidal range between 20 and 50 cm. The coastline is exposed to wind-generated waves from the south-east (SE) to south-west (SW) directions, with the largest significant wave height of 3 m in the Rijeka Bay (Lončar et al., 2014). The highest waves from the SE direction are usually accompanied by storm surges. The heights water elevation of 1.27 m CVD was recorded at the nearby tidal gauge in Bakar Bay, east of Rijeka, on 29th October 2018.

Analizirana je ranjivost obala Primorsko –goranske županije čija je ukupna duljina 1.072 km. Određivanje indeksa ranjivosti obale (CVI) izvršeno je za segmente obale duljine 25 m, a na temelju pet odabranih parametara (varijabli): geološke građe, obalnog nagiba, značajne visine valova, izloženosti plavljenju te postojanja i utjecaja žala. Prikazani rezultati analiza ranjivosti obala pokazali su složenost istraživanog područja, sa značajnim varijacijama indeksa ranjivosti duž obala. Ispitani su i scenariji plavljenja za prognozirani porast morske razine za 60 cm do kraja stoljeća, odnosno 120 cm kod ekstremnih plima. Potvrđena je visoka ranjivost obalnih naselja, prvenstveno zbog izloženosti plavljenju. Pokazalo se da je potrebno stvoriti baze podataka na temelju dovoljno točnih podataka o reljefu kopna i podmorja, geološkoj građi i oceanografskim značajkama, kako bi se mogao odrediti stupanj ranjivosti te mjere umanjenja hazarda i rizika.

Kod Omišlja na otoku Krku, gdje je predviđena izgradnja pristaništa za ukapljeni plin, hidrografskim mjerenjima ustanovljene su tri pličine na dubinama 13,5 i 13,6 m. Zbog sigurnosti plovidbe, morsko dno je moralo biti dublje od 15,4 m. Pomoću hidroakustičkih metoda istraživanja i autonomne ronilice ustanovljena je geološka građa morskog dna. Pličine su oblikovane u čvrstoj karbonatnoj stijenskoj masi. Primijenjena je posebna tehnologija iskopa bez miniranja. Iskopano je 11.000 m3 stijenske mase koja je deponirana u blizini. Izmijenjeno je stanište površine oko 12.500 m2., Near Omišalj on the island of Krk, where the construction of a pier for liquefied gas is planned, hydrographic measurements revealed three shoals at depths of 13.5 and 13.6 metres. For the safety of navigation, the seabed had to be deeper than 15.4 m. The geological fabric of the seabed was determined using a hydroacoustic survey and remote operating vehicle. Shallows are formed in a solid carbonate rock mass. Special technology of excavation without blasting was applied. 11,000 m3 of rock mass was excavated which was deposited nearby. The seabed habitat with an area of about 12,500 m2 was changed.

The Velebit Channel and its marginal basins in the northeastern Adriatic Sea were analyzed in order to reconstruct the geomorphological evolution of this area during the Late Pleistocene and Holocene (130 ka, MIS 5 to MIS 1) using detailed seabed maps, new data on sea-level changes, and submarine investigation. Submerged parts of the canyon, paleodeltas, traces of ancient lakes, and a large polje were discovered by analyzing these maps. Significant climate fluctuation during the Late Pleistocene and Holocene caused large variations in the Adriatic sea-level. On the very indented karst relief, the paleogeographic changes were quite impressive. The paleoflow of the Zrmanja River modeled a canyon in the present Velebit Channel. A reconstruction of the paleoflow of the Zrmanja River shows that it could be traced at least 140 km from the current mouth during the Last Glacial Maximum. The transition from the marine to terestric/freshwater/lacustrine environment in the southeastern part of the Velebit Channel and in the marginal basins took place when the sea level dropped and oscillated between -20 m and -50 m (110 - 70 ka B.P.) after reaching a maximum of +5 m in 125 ka B.P. (MIS 5e). The basin in the northwest remained connected to the Kvarnerić marine basin at sea-level between -50 m and -80 m (70 - 30 ka B.P.). The sea completely receded from the Velebit Channel and Kvarnerić basin became polje during the Last glacial maximum (30 -20 ka B.P.) when the sea level fluctuated between -100 and -120 m, whereas lakes probably remained in the deep depressions. During rapid sea-level rise between 19 and 7 ka B.P. the sea flooded a large part of the Zrmanja paleoriver valey and canyon (all of the Velebit Channel) and the sea penetrated into marginal basins. At the beginning of the stagnation of the Adriatic Sea level 7 ka B.P. a fine example of drowned fluviokarst relief was formed and the dynamics of water in the karst underground became similar to the present.

U ovome radu prezentirani su rezultati istraživanja obalne ranjivosti Primorsko-goranske županije (PGŽ). Istraživanje je provedeno u suradnji s Javnom ustanovom Zavod za prostorno uređenje Primorsko-goranske županije. Rezultati istraživanja koristit će se kao podloga za izradu prostorno-planske dokumentacije. Razvijena je metodologija istraživanja obalne ranjivosti koja je prilagođena specifičnim karakteristikama obale Republike Hrvatske. Indeks ranjivosti obale (CVI) određen je za segmente obale duljine 25 m, i to na temelju pet odabranih parametara (varijabli): geološke građe, obalnoga nagiba, znatne visine valova, izloženosti plavljenju te postojanja i utjecaja žala. Analize su provedene za čitavu obalu PGŽ-a, čija ukupna dužina obalne linije iznosi 1235 km. Prikazani rezultati analiza ranjivosti obala pokazali su složenost istraživanoga područja te znatne varijacije indeksa ranjivosti duž obale. Ispitani su i scenariji ranjivosti s težištem na plavljenju obalnoga područja za prognozirani porast morske razine za 60 cm do kraja stoljeća, odnosno za 120 cm prilikom ekstremnih plima. Pokazalo se to da je potrebno stvoriti baze podataka na temelju dovoljno točnih podataka o reljefu kopna i podmorja, geološkoj građi i oceanografskim značajkama kako bi se mogli odrediti stupanj ranjivosti te mjere umanjenja rizika.

U ovom radu analizirana je ranjivost obala otoka Krka. Određivanje indeksa ranjivosti obale (CVI) izvršeno je za segmente obale duljine 25 m, a na temelju pet odabranih parametara (varijabli): geološke građe, obalnog nagiba, značajne visine valova, izloženosti plavljenju te postojanja i utjecaja žala. Prikazani rezultati analiza ranjivosti obala pokazali su složenost istraživanog područja, sa značajnim varijacijama indeksa ranjivosti duž obale otoka. Ispitani su i scenariji plavljenja za prognozirani porast morske razine za 60 cm do kraja stoljeća, odnosno 120 cm kod ekstremnih plima. Potvrđena je visoka ranjivost obalnih naselja na otoku Krku, prvenstveno zbog izloženosti plavljenju. Pokazalo se da je potrebno stvoriti baze podataka na temelju dovoljno točnih podataka o reljefu kopna i podmorja, geološkoj građi i oceanografskim značajkama, kako bi se mogao odrediti stupanj ranjivosti te mjere umanjenja hazarda i rizika., The paper provides analyses of the Krk Island coast vulnerability. The determination of the coastal vulnerability index (CVI) was carried out for costal segments of 25 m in length and based on 5 selected parameters (variables): geological composition, fabric coastal slope, significant wave heights, exposure to flooding, and the existence and impact of shores. The presented results of the costal vulnerability analyses revealed the complexity of the researched area, with significant variations of the vulnerability index along the island’s coast. Flooding scenarios for the forecast increase in sea levels by 60 cm until the end of the century, i.e. 120 cm at extreme tides were also tested. High vulnerability of the costal settlements on Krk Island was confirmed, primarily due to flooding exposure. It is necessary to create databases with sufficient accurate data on land and seafloor relief, geological composition fabric and oceanographic characteristics to determine the degree of vulnerability and hazard and risk mitigation measures., n diesem Beitrag wird die Vulnerabilität der Küste der Insel Krk analysiert. Der Vulnerabilitätsindex (engl. coastal vulnerability index; CVI) wurde für die Küstensegmente in Länge von 25 m bestimmt und zwar aufgrund der fünf Variablen: geologischer Aufbau, Küstengefälle, signifikante Wellenhöhe, Anfälligkeit gegenüber Überschwemmung und Existenz und Auswirkung des Strandes. Die dargestellten Ergebnisse der Analyse der Küstenvulnerabilität zeigen, dass das Forschungsgebiet einschließlicherheblicher Variationen des Vulnerabilitätsindexes entlang der Inselküsten komplex ist. Die Überschwemmungsszenarien für einen Meeresspiegelanstieg von 60 cm bis Ende des Jahrhunderts bzw. 120 cm bei extrem hohen Flut wurden auch simuliert. Die sehr hohe Vulnerabilität der Küstensiedlungen auf der Insel Krk wurde bestätigt, insbesondere weil sie Überschwemmungen ausgesetzt sind. Es hat sich auch gezeigt, dass Datenbanken aufgrund richtiger Angaben über Land- und Meeresrelief, geologischen Aufbau und ozeanographische Merkmale erstellt werden sollen, um den Vulnerabilitätsgrad und die Maßnahmen bestimmen zu können undsomit Gefahr und Risiko zu reduzieren.

Razvitak progresije i sedimentacije na ušćima Dragonje, Mirne i Raše, ustanovljen je na temelju usporedbe dovoljno preciznih povijesnih karata s onim suvremenim. Usporedba je pokazala izrazito velike promjene u estuariju rijeke Raše, a znatno manje na ušću Mirne. Razlozi različite progresije ušća su velike razlike u produkciji nanosa i erozijska moć vodotoka u slivovima ovih rijeka, ali i djelomično različiti okoliši taloženja. Sedimentacija na ušćima Dragonje i Mirne izložena je djelovanju valova i morskih struja pa se dio sedimenata taloži daleko od ušća. Nasuprot tomu, u dubokom estuariju Raše zbiva se miješanje riječne i morske vode u tri kilometra dugačkoj zoni. Do tridesetih godina 20. stoljeća zaustavljeno je taloženje u nekadašnjim naplavnim ravnicama, kao i prirodne promjene na ušćima tih rijeka zbog regulacije dolinskih dijelova korita. Primjetno je smanjenje pronosa nanosa već od kraja 20. stoljeća zbog smanjenja korištenja poljoprivrednog zemljišta i povećanja šumskih površina.

The tombolo is a depositional geomorphological form (sandbar, barrier or spit) that joins an island or a barrier with the mainland or another island, resulting from longshore drift or the migration of an offshore bar toward the coast (WARD, 2004). Two tombolos, recent and submerged, are on the south-western coast of Prvić Island (Kvarner area, the north-eastern channel part of the Adriatic Sea). Three geomorphological factors are important for the origin of these tombolos: specific geological fabric, oceanographic conditions and sea-level change during Holocene. Prvić Island is mostly formed in carbonate rocks consisting of Upper Cretaceous and Palaeogene carbonate rocks, and partially of Palaeogene siliciclastic rocks (MAMUŽIĆ et al., 1969). Most of the island has a typical karstic landscape. The investigated area close to Cape Pipa is located in the central part of the south-western coast. The coastal relief and geologic fabric are very different in relation to other coastal parts of this island. There Palaeogene flysch bedrock is partially covered by Quaternary sediments. This sediment body has a form of irregular triangle with a base length of approximately 50 m. The height of this deposit is 10 to 12 m. The stratification is well visible in the sediment body, where silty sand prevails. Some layers contain angular fragments and blocks from carbonate rock mass. Cape vertex itself is formed of collapsed blocks of talus breccia and provide an obstacle to wave motion. Beach sediment body connects the cape vertex with the coast. Wind waves from the northwest (tramuntana) and southeast (jugo) generate longshore currents, which are responsible for coastal erosion and accumulation of sediment in the beach bodies. Recent tombolo is in a state of equilibrium in the present climatic and oceanographic condition. Much bigger triangular tombolo form is clearly visible on the sea bottom, southeast from Cape Pipa. Paleo-coastline is approximately 300 m long. Unusual dark parallel lines are clearly visible on the ortho-photo image, where these submerged outcrops look like artificially built walls. The exploration by scuba-diving has revealed that they are outcrops of more resistant sub-vertical layers within the flysch rock mass. Concave traces of ancient coast are clearly visible on the western side and less noticeable on the south-eastern side. This submerged tombolo form was formed behind another obstacle, and it is located at depths up to 10 m. The Njivice Rock is built of relative resistant carbonate breccia. The conditions for forming a submerged tombolo could have occurred during the sea-level rise during the late Pleistocene and Holocene (SURIĆ, 2009 ; TSIMPLIS et al., 2009). The sea has flooded the submerged tombolo probably in the last phase of rapid sea-level rise at the beginning of Holocene. A large part of less resistant Quaternary sediments and fine-grained flysch rock mass were eroded. Njivice Rock played an important role in the formation of the tombolo. This rock provided an obstacle to waves in the shallow and flattened area. Two generations of tombolos co-existing at close proximity is a unique phenomenon in the Adriatic Sea, and possible in the Mediterranean Sea. This work has been supported in part by the University of Rijeka (Uniri-tehnic-18-97 1232) and GEOSEKVA (HRZZ IP-2016-06-1854).

Žalo duljine oko 70 m nalazi se u uvali Uboka, na zapadnoj obali Riječkog zaljeva, podno padina Učke, približno 1, 5 km južno do Mošćeničke Drage. Od 2. siječnja do 12. travnja 2012. godine provedeno je 11 mjerenja topografije žala. Korištena je Structure-from-Motion (SfM) fotogrametrija pomoću koje su generirani trodimenzionalni oblaci točaka visoke preciznosti i razlučivosti. Korištena metodologija je omogućila povoljno i brzo snimanje geomorfoloških promjena. Zabilježene su značajne promjene tijela žala prouzročene uzajamnim djelovanjem valova i istjecanjem površinskih i podzemnih voda kada dolazi do erozije žala oblikovanjem kanala kroz njegovo tijelo. Nakon prestanka istjecanja žalo se brzo oporavlja, odnosno poprima prvotni oblik djelovanjem vjetrovnih valova. Na mjestu kanala brzo se formira berma žala, najprije ona uža, a nakon toga stabilna široka i visoka berma. U slučaju kanaliziranja bujičnih vodotoka na ušću žala dolazi do znatnog povećanja brzina toka o odnosu prirodan način otjecanja, koji je opisan u ovom radu, zbog čega može doći do trajne erozije žala.

Bakarski zaljev obiluje priobalnim i podmorskim izvorima. Zbog nižeg položaja vodonepropusnih siliciklastičnih stijena (lapora i fliša) koji ima ulogu regionalne hidrogeološke barijere, u područje Bakarskog zaljeva drenira se voda iz relativno veliko krškog zaleđa. Zato se upravo na sjeveroistočnoj obali Bakarskog zaljeva nalazi jedna od najvećih koncentracija izvora na hrvatskoj obali Jadranskog mora. Izvori u Bakarskom zaljevu mogu se podijeliti u dvije grupe. Na sjeverozapadnom dijelu zaljeva, oko grada Bakra, nalaze se pojedinačni izvori veće izdašnosti: Perilo, Jaz, Lovrinac, Podbok, Dobra i Dobrica, kao i kaptažna galerija Perilo. Na jugoistočnoj strani zaljeva, između lokacija Črno i Žminjca, nalazi se veći broj manjih priobalnih izvora, vrulja i lokaliteta s istjecanjima kroz brojne pukotine. Prema hidrološkim bilancama, upravo na tim neotkrivenim mjestima vjerojatno istječu velike količine podzemnih voda u more. Razlog tomu često je složen i nedovoljno poznat položaj vodopropusnih okršenih karbonatnih i vodonepropusnih siliciklastičnih stijena. Ubrzan rast razine Jadranskog mora od mlađeg pleistocena i tijekom holocena, kao i njegova relativna stagnacija posljednjih nekoliko milenija imale, uz geološku građu, su ključnu ulogu u recentnom položaju zona izviranja.

The European Marine Observation and Data network (EMODnet) is focused on projects assembling marine data, products and metadata into a standardised and harmonised marine data which are interoperable and free of restrictions on use. EMODnet geology (one of seven EMODnet projects) has the goal to compile existing data on European seas related and to deliver where possible harmonised 1:250, 000 and 1:100, 000 maps of the sea-bed substrate, the rate of accumulation and/or sedimentation on the sea- floor ; geological boundaries and faults ; geological events and event probabilities and minerals and submerged landscapes. Information on coastal type and behaviour is supplemented by information on coastal erosion or sedimentation and the rate at which it occurs. The geological data the Croatian part of the Adriatic sea covers a total marine area of 55 349 km². Within the project the first digital sea-bed substrate map of the Adriatic was harmonized and digitised with the most recent available data. Also some ten maps scale 1:25000 made during surveys in the 1980’s were later incorporated into the “Seabed substrate of the Adriatic sub-region“. Within the project an attempt was made to develop the first digital pre-quaternary sea-floor geology map of the Croatian part of the Adriatic sea based on seismic and well data . Since the objective was to compile and harmonise all available sea-bed geology (outcrop and sub-Quaternary) information at a scale of 1:250, 000 it was necessary to make completely new maps. The new maps were derived based on 53 exploration wells located in the Croatian part of the Adriatic sea and selected seismic profiles from the more than 80 000 km of 2D seismic data. The information on the type and behaviour of coastal landforms along the entire coastal zone was made based on simplified method used for the EUROSION project the resolution of the data was 1:100 000. This is also the first digital map of this type made for the Croatian coast. The data will be essential not only for geologists but also for others interested in marine geological data like marine managers, habitat mappers and archaeologists and is available at the following site: http://www.emodnet.eu/geology. The EMODnet geology project is in its third phase in which even more detailed dana and maps will be available. European Marine Observation and Data Network (EMODnet) is supported by a dedicated Secretariat funded by the European Commission (tender MARE/2012/15).

U radu su analizirane geomorfološke promjene u naplavnim dolinama i ušćima rijeke Dragonje, Mirne i Raše koje teku po istarskom poluotoku. Promjene su ustanovljene usporedbom povijesnih karata sa suvremenim. Najstarije karte za područje doline Raše datiraju iz druge polovice 18. stoljeća, a za područje Dragonje i Mirne iz prve polovice 19. stoljeća. Usporedba je pokazala izrazito veliku progresiju ušća Raše, a manje promjene na ušću Mirne, dok na ušću Dragonje nisu vidljive promjene zbog uređenja solane. Produkcija nanosa događa se zbog erozije lapora i fliša u uzvodnim područjima slivova. Većina sedimenata do ušća dolazi u obliku suspenzije. Nakon radova na regulaciji zaustavljeno je plavljenje u dolini Mirne i Raše, a u dolini Dragonje pedesetih godina 20. stoljeća. Nakon toga, promjene su vidljive samo po smanjenju dubine morskog dna oko ušća. Primjetno je smanjenje pronosa nanosa već od kraja 20. stoljeća, zbog smanjene obrade zemljišta i širenja šuma.

U rječniku nalazi se objašnjenje 810 pojmova i 133 fotografije. Rječnik je interaktivan i također sadrži kazalo pojmova na hrvatskom i engleskom jeziku.

U ovom radu opisana je ranjivost obala otoka Raba koja može biti prouzročena prognoziranim porastom razine mora do kraja 21. stoljeća. Opisane su posljedice koju taj prirodni fenomen može prouzročiti. Analizirana su tri scenarija pojava visoke razine mora: kod stagnacije globalne morske razine, te kod porasta za 30 i 60 cm. Analize su napravljene na topografskim kartama mjerila 1:5000. Ustanovljene su najugroženije urbanizirane obalne zone: uvala Sv. Eufemija, luka grada Raba, Supetarska Draga i uvala Lopar. Procijenjen je utjecaj povišenja morske razine na djelovanje valova u istraženim obalnim zonama. Kao posljedica porasta morske razine može se očekivati širenje zaslanjenih priobalnih zona na poljoprivredne površine. Vjerojatno će se pojačati marinska erozije na obalama, što će prouzročiti nazadovanje klifova i/ili smanjenje tijela brojnih pjeskovitih žala. Problem može biti i otežana odvodnja s niskih i zaravnjenih dijelova terena kao i rad lokalne oborinske i fekalne kanalizacije. Mogu biti ugroženi i stambeni objekti koji su posljednjih desetljeća izgrađeni u niskim obalnim zonama, kao i neke građevine u srednjovjekovnoj gradskoj jezgri Raba.

Numerous instability phenomena have been recorded in the Rjeˇcina River Valley, near the City of Rijeka, in the past 250 years. Large landslides triggered by rainfall and floods, were registered on both sides of the Valley. Landslide inventory in the Valley was established based on recorded historical events and LiDAR imagery. The Rjeˇcina River is a typical karstic river 18.7km long, originating from the Gorski Kotar Mountains. The central part of the Valley, belongs to the dominant morphostructural unit that strikes in the northwest-southeast direction along the Rjeˇcina River. Karstified limestone rock mass is visible on the top of the slopes, while the flysch rock mass is present on the lower slopes and at the bottom of the Valley. Different types of movements can be distinguished in the area, such as the sliding of slope deposits over the flysch bedrock, rockfalls from limestone cliffs, sliding of huge rocky blocks, and active landslide on the north-eastern slope. The paper presents investigation of the dormant landslide located on the south-western slope of the Valley, which was recorded in 1870 in numerous historical descriptions. Due to intense and long-term rainfall, the landslide was reactivated in 1885, destroying and damaging houses in the eastern part of the Grohovo Village. To predict possible reactivation of the dormant landslide on the south-western side of the Valley, 2D stability back analyses were performed on the basis of landslide features, in order to approximate the position of sliding surface and landslide dimensions. The landslide topography is very steep, and the slope is covered by unstable debris material, so therefore hard to perform any terrestrial geodetic survey. Consumer-grade DJI Phantom 2 Remotely Piloted Aircraft System (RPAS) was used to provide the data about the present slope topography. The landslide 3D point cloud was derived from approximately 200 photographs taken with RPAS, using structure-from-motion (SfM) photogrammetry. Images were processed using the online Autodesk service “ReCap”. Ground control points (GCP) collected with Total Station are identified on photorealistic point cloud and used for geo-referencing. Cloud Compare software was used for the point cloud processing. This study compared georeferenced landslide point cloud delivered from images with data acquired from laser scanning. RAPS and SfM application produced high accuracy landslide 3D point cloud, characterized by safe and quick dana acquisition. Based on the adopted rock mass strength parameters, obtained from the back analysis, a stability analysis of the present slope situation was performed, and the present stability of the landslide body is determined. The unfavourable conditions and possible triggering factors such as saturation of the slope, caused by heavy rain and earthquake, were included in the analyses what enabled estimation of future landslide hazard and risk.

Vinodolska dolina je smještena na području zapadnog dijela Republike Hrvatske u Primorsko-goranskoj županiji. Dolina ima nepravilan eliptični oblik duljine do 22 km te izduženo pružanje osnovnim smjerom SZ-JI. Na osnovi geomorfoloških značajki se prostor može podijeliti u tri dijela: sjeverozapadni, središnji i jugoistočni. Sjeverozapadni dio doline površine oko 24 km2 obuhvaća područje od naselja Križišće do naselja Janjevalj i Pećca, smještenih na početku središnjeg dijela. Najveća širina doline do 4 km je prisutna u središnjem dijelu, koji u površini od oko 30 km2 obuhvaća područje sve do prijevoja kod naselja Saftići i Kričina. Ovdje započinje jugoistočni dio, površine oko 23 km2 i gotovo ujednačene širine do 2, 70 km, koji se proteže do završetka doline u zaleđu Novog Vinodolskog. Sjeveroistočni rub Vinodolske doline izgrađuju karbonatne padine čiji vrhovi mjestimično premašuju 800 m.n.m., a u središnjem i jugozapadnom dijelu poprimaju oblike gotovo vertikalnih stjenovitih litica (BERNAT et al., 2014). Jugozapadni rub izgrađuje niže primorsko karbonatno bîlo, čije su padine drugačijih morfoloških karakteristika od nasuprotnog strmijeg ruba. Zbog različitih morfoloških obilježja padina, Vinodolska dolina u svom većem dijelu ima izrazito asimetričan poprečni profil. Niže dijelove sjeveroistočnih padina te dno doline izgrađuje eocenski flišni stijenski kompleks, u kojem stariji dio tvori tipična izmjena siltita i pješčenjaka te u podređenom udjelu lapora, brečokonglomerata i vapnenaca, a diskordantni mlađi dio sastoji se od konglomerata, konglomeratičnih biokalkarenita i litičnih arenita (BLAŠKOVIĆ & TIŠLJAR, 1983). Najrašireniji tip pokrivača na flišu predstavljaju deluvijalno-koluvijalne naslage, čija je debljina veća na sjeveroistočnim padinama. Kvartarne siparne breče relativno ujednačenog nagiba zastupljenije su na sjeveroistočnim padinama, gdje se pojavljuju u obliku ploča na višoj hipsometrijskoj razini u odnosu na flišnu stijenu u podlozi (BLAŠKOVIĆ, 1983). Zbog zajedničkog utjecaja geološke građe, složenih strukturno-tektonskih odnosa, hidrogeoloških značajki naslaga i hidroloških uvjeta, na većem dijelu Vinodolske doline izraženi su aktivni geomorfološki procesi koji rezultiraju pojavama nestabilnosti na padinama. Nestabilnosti se očituju u obliku pojava erozije različitog tipa i stupnja izraženosti (BENAC et al., 2005), brojnih pojava klizišta i puzanja dijelova terena u naslagama flišnog stijenskog kompleksa, ali i drugih oblika pojava nestabilnosti (BERNAT et al., 2014). Preliminarni inventar klizišta na području Vinodolske doline je rezultat nastavka istraživanja u okviru kojega je provedena identifikacija i kartiranje klizišta na području sliva rijeke Dubračine (ĐOMLIJA et al., 2014). Inventar klizišta u Vinodolskoj dolini izrađen je na temelju vizualne interpretacije površinske morfologije digitalnog modela terena visoke rezolucije. S obzirom da je dio površine antropogeno izmijenjen, određene pojave klizišta nije moguće jasno raspoznati na digitalnom modelu terena. Iz tog razloga je daljinska metoda identifikacije i kartiranja klizišta nadopunjena prospekcijskim geomorfološkim terenskim kartiranjem i kartiranjem oštećenja na prometnicama i stambenim objektima nastalih kao posljedica pojava klizišta. Digitalni model terena visoke rezolucije je izrađen na temelju podataka prikupljenih laserskim skeniranjem iz zraka, ALS (eng. airborne laser scanning) koje predstavlja jednu od najučinkovitijih suvremenih tehnologija daljinskih istraživanja, naročito u svrhu kartiranja klizišta (JABOYEDOFF et al., 2012 ; GUZZETTI et al., 2012). Osnovni instrument u primjeni ALS-a je LiDAR (eng. Light Detection and Ranging) čiji se princip prikupljanja podataka zasniva na mjerenju udaljenosti između laserskog skenera pričvršćenog za letjelicu i površine terena ili nekog drugog objekta. Naknadnom obradom podataka moguće je ukloniti impulse reflektirane s objekata i vegetacije, da bi se proizveo digitalni model terena bez vegetacije (eng. ''bare-earth'') (VAN DEN EECKHAUT et al., 2007). Lasersko skeniranje područja Vinodolske doline provedeno je krajem ožujka 2012. s postignutom gustoćom od 5 točaka po m2. Iz generiranog digitalnog modela terena rezolucije 1 m x 1 m su pomoću standardnih operacija u ArcGIS-u derivirane tri vrste topografskih karata koje su korištene za vizualnu interpretaciju topografskih značajki površine terena indikativnih za pojavu klizišta: karte osjenčanog reljefa izrađene simulacijom sunčevih zraka za dva različita azimuta položaja sunca od 315° i 45° pri konstantnom kutu upada sunčeve svjetlosti od 45° ; karta nagiba terena ; i karta slojnica s ekvidistancijom od 1 metar. Inventar klizišta u Vinodolskoj dolini sastoji se od 141 ustanovljenih klizišta te 40 pretpostavljenih klizišta. S obzirom da u ovoj fazi istraživanja nisu iscrtane granice svih utvrđenih klizišta, inventar je preliminarni i sadrži podatke o njihovim lokacijama i prostornoj distribuciji, koja je izrazito neujednačena. U sjeverozapadnom dijelu doline utvrđeno je 11 klizišta, a pretpostavljeno je jedno klizište. Klizišta su trajno ili privremeno umirena, smještena na blago nagnutim padinama i koncentrirana na prostoru između početka doline i naselja Drivenik. Najveći broj klizišta je utvrđen na području sliva rijeke Dubračine smještenog u središnjem dijelu Vinodolske doline, gdje je identificirano 109 klizišta, a pretpostavljeno je 30 klizišta. Na ovom području je vrlo izražen proces erozije jaružanjem koji rezultira nastankom i produbljivanjem jaruga u čijim je relativno strmim bokovima formiran najveći broj aktivnih klizišta. U bokovima ukupno osam jaruga, koje predstavljaju korita povremenih bujičnih vodotoka, utvrđeno je 90-ak pojava klizišta. Riječ je o malim i plitkim klizištima, pretpostavljenih volumena u rasponu između 103 do 105 m3, koja u kombinaciji sa spomenutim procesom erozije vrlo često uzrokuju oštećenja na dijelovima prometne infrastrukture i stambenim objektima. Kao i na području sjeverozapadnog dijela doline, tako je i u središnjem dijelu utvrđen određeni broj trajno ili privremeno umirenih klizišta na blaže nagnutim padinama, čija je morfologija nerijetko izmijenjena pod antropogenim utjecajem. Radi se o većim klizištima (volumena > 105 m3) s pretpostavljenim dubinama kliznih ploha između 10 i 15 m. Posljednja značajnija aktiviranja klizišta u ovom dijelu Vinodolske doline dogodila su se u svibnju 2013. na dijelu lokalne ceste L58075 te u veljači 2014. na području zaseoka Kamenjak. U jugoistočnom dijelu Vinodolske doline identificirano je 21 klizište, a pretpostavljeno ih je osam. Deset klizišta je formirano u područjima bokova triju jaruga kao posljedica kombiniranog djelovanja procesa klizanja s procesom erozije, a zabilježeno je i nekoliko pojava aktivnih klizišta na padinama oko naselja Kričina i Ugrini.

Vinodol Valley, situated in western Croatia in the Primorsko-Goranska County, represents an area of wide range of different landform types, each characterized by specific processes and materials which create them. Necessity of study of geological hazards in the Vinodol Valley arises from the continual direct damaging impact of different hazardous processes on public roads and private material properties. Sliding and erosion processes thus cause great economic losses for the local government and residents. Study of past and recent hazardous processes in the Vinodol Valley has been conducting with the aim to create susceptibility and hazard maps depicting potential for all processes causing slope instabilities. In this respect, the essential step for reliable landslide susceptibility assessment is to select an appropriate terrain subdivision, i.e., creating individual mapping units based on the certain criteria (Van den Eeckhaut et al., 2009). Delineated mapping unit thus represents a homogeneous portion of the land surface characterized by a set of ground conditions that differ the unit from the adjacent ones across definable, closed boundary (Evans, I., 2012). Methodology of research of hazardous processes in the Vinodol Valley is based on the geomorphological approach which implies delineation of geomorphological units on the basis of identification of topographical landform characteristics, materials which create them and its past and recent landslide and erosion processes and phenomena. Current study of the Vinodol Valley presents extension of the preliminary investigations of landforms and geomorphological processes at the area of Dubračina River Basin, where different geomorphological units were outlined characterized by typical types of landslides and erosion phenomena (Bernat et al., 2014). Dubračina River Basin of 43, 5 km2 covers nearly the half of the territory of the Vinodol Valley, i.e., its northwestern and central part. Vinodol Valley, with its length of approximately 22 km and maximum width of 4 km, has pronouncedly elongated shape and characteristically asymmetrical cross section in which the prominence of longer northeastern and shorter southwestern slopes is present. Moreover, three different geomorphological zones exist along the valley. The first zone extends from the Križišće settlement in the northwestern part to the Janjevalj and Pećca setllements in the southeastern direction. The length of this zone is approximately 7, 5 km and the width ranges from 950 m to 3, 50 km. The second zone, with length of about 6, 5 km and maximum width of 4 km, extends from Janjevalj and Pećca settlements to the Saftići and Kričina settlements. The third zone is characterized by mostly uniform width of about 2 km and extends from Saftići and Kričina settlements to the city of Novi Vinodolski situated at the sea coast at the end of the valley. For identification of geomorphological units and hazardous processes in the Vinodol Valley high resolution airborne LiDAR-derived imagery of resolution 1 x 1 m was primarily used. Visual interpretation was undertaken to identify all the types of sliding processes and sliding and erosion phenomena. Field investigations were conducted to identify the types of materials of which the area of Vinodol Valley was built and to additionally identify sliding phenomena which were recognized with uncertainty on the LiDAR-derived imagery. The criteria adopted for identification of specific geomorphological unit were morphological characteristics and internal relief, types of material defined by lithology of base rock mass and superficial deposits, and types of identified geomorphological processes and phenomena. Identified processes causing slope instabilities in the Vinodol Valley can be generally categorised into two main groups: erosion and sliding processes. Among erosion phenomena planar erosion, gully erosion and excessive erosion can differ. Identified sliding phenomena encompass rock falls, topples, landslides, mud flows and instabilities in scree deposits. Features of historical debris flow were also identified. In the paper types and spatial extent of all types of hazardous phenomena per geomorphological unit type were analysed together with possibilities of visual identification of the phenomena from high-fidelity DEM.

The coastal zone around Stara Baška settlement (the SW coast of the Island of Krk, NE channel part of the Adriatic Sea) is in delicate geodynamic balance. Wide areas are formed in karstified carbonate rocks. Gentle inclined carbonate rocky coasts are generally stable, destructive wave influence is small and bioerosion prevails. Siliciclastic rocks (marls and flysch) covered by different type of slope deposits are in a narrow coastal zone and marine erosion is more pronounced. Aerial photo from 1966 and ortho-photo map from 2004 show considerable coastal changes and recorded cliff retreat is up to 5 metres. Strong wave attack and wave-cut notches formation are the main cliff instability causes in talus breccias. The combination of extensive erosion and sliding are common on the coasts formed in strongly weathered siliciclastic rocks and cohesive slope formation. The narrow gravel beach absorbs most of the wave mechanical energy during average see levels. However, during extreme storm surges, the waves reaches the cliff’s toe and can contribute to the cliff undercut formation and furthermore cliff retreat. According to the predicted sea-level rise, the susceptibility of marine erosion and consequently slope instabilities will be higher.

In this paper karstic relief, with an emphasis on distribution of dolines and linear forms will be presented. The Island of Krk is one of two biggest Adriatic islands (405 km2). It is located in the north-eastern part of the Adriatic Sea channel area, between the Istrian peninsula and the Vinodol –Velebit coast. This island consists mainly of carbonate rocks: Cretaceous limestones, dolomitic limestones and dolomitic breccias, Palaeogene limestones and carbonate breccias. Outcrops of siliciclastic rocks (marls and flysch) are restricted in relatively narrow, compressed and isolated zones. This island is part of the External Dinarides, and its major orographic axis and geological structures have a Dinaric strike (NW–SE to NNW–SSE). This dominant strike of tectonic structures has been disturbed by younger diagonal and transverse strike-slip faults during the Pliocene and Quaternary under the influence of re-oriented, a neotectonic regional stress orientated approximately N–S (VLAHOVIĆ et al., 2005). Due to this, carbonate rock mass are partially extremely deformed and fissured. Present landscape of the Island of Krk is a consequence of simultaneous influence of tectonic movements, and climatic and sea-level changes during Pliocene and Pleistocene. Due to complex tectonic fabric karst forms that occur on the Island of Krk are numerous and various. Diversity of karst forms has been previously noticed by BENAC et al. (2013). Using a combination of topographic maps (scale 1:5.000), geometrically corrected aerial photography (in resolution 0.5 m, dating in 2004) and field work all together 5.610 depressions and more than 742 km of linear forms, both of various types, have been detected on carbonate rocks. Depressions are mainly dolines of accelerated dissolution type, partly or completely filled with sediments. They reach the density of 61 dolines/km², with average distance 〖dist〗_avg = 108 (with simmilar values in entire area) and median diameter d_m = 48 m. With decrease of their size the dispersion of dolines distribution over entire area markedly increases. It is evident that dolines developed quite independently of lithology. The main factor of their distribution seems to be recent relief configuration ; however, they have been detected even under Quaternary deposits. On spatially opposite locations, mainly on slopes with higher inclination, appear valley-like forms of tectonic, paleofluvial, tecto-karstic, karstic and not yet completely defined origin (Fig.1). Linear forms of tectonic origin are young surface forms, formed mainly by gravitational processes. Morphometrically they are short and unbranched, and developed on steep slopes. They clearly show recent tectonic activity of the area on north-eastern edge of the island and in the south. Tecto-karstic linear forms can seem fluvial in appearance, but have developed by accelerated corrosion along geologic structures with increased permeability. The most obvious tecto-karstic forms developed along strata with high dip. The majority of linear forms on carbonates however follow principles of fluvial erosion: some well-branched systems with direction towards local baselevel reach a length of even 15 km. These old well branched paleofluvial networks with complex drainage patterns (2nd or 3rd order) developed in recently tectonically inactive areas, some of them nowadays being located on high karst plateaus. These forms are now inactive in fluvial sense but are still subject to processes of karstification. They developed characteristic smooth relief with lack of accumulated fluvial and gravitational material. Some of them were strongly tectonically disturbed and have adapted to the drop of groundwater level by cutting canyons in their lower parts of the streams. Clear evidences of contact karst (blind valleys) are rare. Denuded caves which also appear as shallow irregular linear forms with traces of sinter were located in the south of the area. The majority of valley forms on carbonates are recently dry. Partly and periodically active are solely valleys which cross zones of non-carbonates. Findings of sandstone remnants in the upper parts of valleys proved that non-carbonates covered much wider areas, or that compressed zones of non-carbonates were much more numerous than it was thought. This might have partly contributed to development of complex drainage networks in this bare-rock landscape of today. The distribution of dolines and valley forms clearly express the competitive relationship between point and linear geomorphic processes. However, the origin of all types of linear forms has not been satisfactory explained yet. Even though relief forms follow the principle of surface runoff, deposit sediments and form complex drainage networks, there have been clear traces of depth karstification found in the same regions as well.

The paper presents the summary of the existing and past instabilities on the road Cerovlje- Buzet, as well as reflect on the landslide hazard in the area. The area is mostly built in Paleogene flysch sediments, with the prevailing grey colour, due to which it is called Grey Istria. Small rotational and translational landslides prevail in flysch deposits in central Istria, due to sliding of the cover on the contact with the flysch bedrock. Present instabilities and road damages caused by landslides were established by terrain inspection. Research area was determined by the existing road section Cerovlje- Buzet, 12 700 m in length. The road spreads from the central (Cerovlje), to the northern part of the Istrian Peninsula, beneath the Učka Mountain (Buzet). Signs of active and inactive landslides in the described location were analysed: scars and cracks on the road, depressions on the slopes along the road, presence and inclination of the fast growing vegetation inside the landslide body, visible landslide and sliding surface boundaries, hilly slopes characteristic for the flysch deposits etc. Using GPS device, locations with present marks of sliding, together with the locations where remedial measures were already done in the past (most often reinforced concrete retaining walls or gabions) were recorded. Research results were presented on the ortophoto map. Larger instable zones with landslide hazard potential, that could endanger usual traffic and human lives, were also presented. It can be concluded that the damages on the road are numerous and that the instabilities overtake different areal extent, but that they are mostly relatively small landslides. Based on the research performed in this paper, considerable landslide hazard in the area can be expected. Using adequate and available methodology, the real landslide hazard degree, along the Cerovlje- Buzet road, could be determined.

Studijom su obuhvaćeni rezultati mjerenja lokacije Vela plaža, Zarok i Palada na području naselja Baška na otoku Krku. Osim snimanja napravljena je analiza postojećeg stanja žala te je uspostavljena baza podataka za sustavni monitoring cijelog područja. Studija je zaključena preporukama za daljnja mjerenje (monitoring) te preporukama za održivo upravljanje obalnog područja Baške.

The Kvarner area is a semienclosed part of the Adriatic Sea located between the Istrian Peninsula and the Vinodol–Velebit coast. The island chains Cres–Lošinj and Krk–Rab–Pag divide it into the Rijeka Bay, the Kvarner, Kvarnerić and the Velebit–Vinodol Channel. The wave heights in the channel part of the northern Adriatic Sea are smaller than in the western open zone due to relatively short wind fetch. Hence the strongest northeastern wind Bura (or Bora) does not generate the highest waves. On the other hand, on the western open coast of Cres and Lošinj islands, the stormy southeastern wind Jugo (or Scirocco) can generate waves higher than 6 m. In the terrestrial part of the Kvarner area Cretaceous carbonate sedimentary rocks (limestone, dolomites and carbonate breccia), Paleogene limestone (foraminiferal limestone) and Paleogene siliciclastic rocks (marls and flysch) are present. Carbonate rocks prevail, whereas siliciclastic outcrops are restricted. Pleistocene and Holocene deposits partly cover this bedrock substrate. Intensive morphogenetic processes caused by tectonical movements and rapid sea-level changes, as well as climatic changes, caused the present shape of the Kvarner area. Slow sea-level rise during the last 6, 000 years created conditions for more intensive marine erosion. Marine abrasion caused by wave impact is not very pronounced due to its sheltered position and coastal geological settings in the Kvarner area. In places where the rock mass is tectonically crushed or/and karstified, wave notches and cliffs evolve. The destructive impact of waves is more pronounced in coasts formed in siliciclastic rocks, even in sheltered zones, where wave energy is low. There, a different effect of wave erosion is observed. Cliffs are formed in more resistant sandstones, whereas mass movements, earth flows and rockfalls are common in less resistant marls. Gentle inclined carbonate rocky coasts are generally stable, without visible mass movements. Against that, different types of mass movements are common on very steep and subvertical coastal parts. These morphodynamic processes are clearly visible along the north and northeastern coasts of the Cres Island, southeastern coast of the Plavnik Island and north and southwestern coast of the Krk Island. Similar types of instabilities have been found near very steep northeastern coasts of the Rab, Prvić, St Grgur and Goli islands. These phenomena are also visible along the western coast of the Rijeka Bay: between the Plomin Bay and the Mošćenička Draga valley, in the northeastern part of the Bakar Bay and sporadically along other steep coasts. Active scree and rockfall prevail on rocky scarps. Somewhere, the traces of planar or wedge failures are visible. The rests of dormant debris flows are situated in several dry karstic valleys. Remarkable phenomenon is a combination of tectonic subsidence and huge rocky slide on the eastern coast of the Rijeka Bay. The destructive impact of waves is more pronounced in the coasts formed in siliciclastic rocks. Slope and marine erosion prevail, but somewhere different types of landslide are found. Active or dormant slide are visible in the southeastern coast of the St. Marko Island, near the Jadranovo settlement (northeastern coast of the Vinodol-Velebit channel) in the Murvenica cove (northeastern coast of the Krk Island) and near Stara Baška settlement (southwestern coast of the Krk Island). Instability phenomena along the coasts of The Kvarner area are a part of very complex morphodynamic processes which include sea level change and seismotectonic activity.