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In March 2018, a landslide in Hrvatska Kostajnica completely destroyed multiple households. The damage was extensive, and lives were endangered. The question remains: Can it happen again? To enhance the knowledge and understanding of the soil and rock behaviour before, during, and after this geo-hazard event, multi-level sensing technologies in landslide research were applied. Day after the event field mapping and unmanned aerial vehicle (UAV) data were collected with the inspection of available orthophoto and “geo” data. For the landslide, a new geological column was developed with mineralogical and geochemical analyses. The application of differential interferometric synthetic aperture radar (DInSAR) for detecting ground surface displacement was undertaken in order to determine pre-failure behaviour and to give indications about post-failure deformations. In 2020, electrical resistivity tomography (ERT) in the landslide body was undertaken to determine the depth of the landslide surface, and in 2021 ERT measurements in the vicinity of the landslide area were performed to obtain undisturbed material properties. Moreover, in 2021, detailed light detection and ranging (LIDAR) data were acquired for the area. All these different level data sets are being analyzed in order to develop a reliable landslide model as a first step towards answering the aforementioned question. Based on applied multi- level sensing technologies and acquired data, the landslide model is taking shape. However, further detailed research is still recommended.

The Kravarsko settlement area, in northern Croatia, has multiple landslides and damage to buildings and infrastructure caused by landslides. However, actual landslide investigation data for the wider Kravarsko area (pilot area PA1) is relatively sparse and no landslide inventory or typical landslide model exists. The aim of this research was to develop such a landslide inventory by integrating new approaches in geohazard research such as remote landslide mapping from high resolution digital elevation models (DEMs) and current and historical aerial images with existing and new geological data related to landslides. The conclusion is that detailed DEMs are more than adequate for the development of reliable landslide inventories but field checks are still necessary to account for the specific set of natural and man-made conditions found in the research area. The landslide inventory developed for Kravarsko has been field validated in a smaller validation area (VA1) and a typical simplified landslide model for PA1/VA1 was developed. Within the model, sliding is interpreted as complex with multiple generations of sliding and multiple sliding surfaces. Based on the analysis undertaken and the available field data, around 10-20% of urban structures are endangered in the Kravarsko area and anthropogenic activity was determined as an important landslide triggering factor for landslide activation or reactivation. Still the question remains of how to quantify the anthropogenic influence? The developed landslide inventory for PA1/VA1 could be used for local urban planning/development and endangerment assessment/evaluation.

The Croatian Geological Survey (HGI-CGS) is twinning with the world-leading geosciences research institutes, the Geological survey of Denmark and Greenland (GEUS) and the British Geological Survey (BGS-UKRI), ti significantly strengthen HGI-CGS's research, and, in a number of areas, transform it's capability. Within GeoTwinn catrography was utilized in different aspects.

The Miocene deposits of the Hrvatska Kostajnica area belong to the south-western marginal belt of the Pannonian Basin System. Sedimentological, paleontological and mineralogical investigations were performed on Kubarnovo brdo – Stari put landslide. Soil breakdown and sliding formed 30 m outcrop of the Badenian–Sarmatian marly deposits. The landslide was initiated by sudden snow melt with simultaneous precipitation which was accompanied by extremely high water level of the Una River. As a consequence of climatic conditions, the marly sediments rich in swelling mineral smectite were completely saturated with water. The slope collapse was also influenced with other unfavorable conditions: slope inclination toward Una river, geological conditions and anthropogenic activity. Badenian and Sarmatian sediments of this area were deposited in marine offshore with local input of terrigenous material represented with marls and silty marls with sand intercalations. The calcite content in the geological column varies from 33 to 88 %. Marls predominantly consist of calcite and clay minerals, while quartz is less abundant. Among clay minerals, in the less than 2 μm insoluble residue fraction, smectite is the most abundant while illite and kaolinite and in some samples chlorite were also determined. The heavy minerals association of the silty marls consists of most resistant minerals: garnet, tourmaline, zircon and rutile together with clinoptiolite indicating local origin of the material. According to palynofacies deposition occurred in a marginal environment under the periodically high terrestrial influence. The land was partially covered by swamp vegetation (Taxodiaceae), riparian forest (mostly Carya) and hillside–piedmont forest (mostly Pinus). Palynomorph assemblage is dominated by dinocysts such as Lingulodinium machaerophorum, Spiniferites div. sp., Cleistosphaeridium placacanthum, Melitasphaeridium choanophorum that point to the Polysphaeridium zoharyi– Lingulodinium machaerophorum Zone (Pzo-Lma) of the latest Badenian–Sarmatian age (Bakrač et al. 2012). Occurrence of small, microperforate planktonic species of the genera Tenuitella and Tenuitellinata are well documented in the Transylvanian Basin. According to Filipescu and Silye (2008), these small planktonic foraminifera occur in the uppermost Badenian– lowermost Sarmatian, just above the Velapertina Zone and slightly before the Anomalinoides dividens Zone. Highly oxic, shallow to middle water depth is the ideal environment for this foraminiferal group (Majewski 2003). The para-acme of Sphenolithus heteromorphus and the (FAD) of Helicosphaera HOL dalmaticus type (Syracolithus dalmaticus), noticed at the base of the section, marks Badenian NN6a subzone, while FAD of Discoaster kugleri, in its upper part, marks the early Sarmatian NN7 Zone of calcareous nannofossils for the Paratethys (Mărunţeanu 1999). Based on higher species diversity characteristic for the world’s ocean of lower latitudes (O’Brien et al. 2016) and dominations of warm water species (larger Coccolithus pelagicus, Umbilicosphaera jafari, small reticulofenestrids) indicate the MMCT. References Bakrač K., Koch G. and Sremac J. 2012. Middle and Late Miocene palynological biozonation of the south-western part of Central Paratethys (Croatia). Geologia Croatica, 65/2: 207–222. Filipescu S. and Silye L. 2008. New paratethyan biozones of planktonic foraminifera described from the Middle Miocene of the Transylvanian Basin (Romania). Geologica Carpathica, 59: 537– 544. Majewski W. 2003. Water-depth distribution of Miocene planktonic foraminifera from ODP site 744, Southern indian Ocean. Journal of Foraminiferal Research, 33: 144–154. Mărunţeanu M. 1999. Litho- and Biostratigraphy (calcareous nannoplankton) of the Miocene deposits from the outer Moldavides, Geologica Carpathica, 50: 313–324. O’Brien C.J., Vogt M. and Gruber N. 2016. Global coccolithophore diversity: Drivers and future change, Progress in Oceanography, 140: 27–42.

Črešnjevec is one of the largest and long- active landslides in southern hilly zone of Medvednica Mt. that belongs to residential area of the City of Zagreb and where the problem with landslides occurs for decades. The first activity of Črešnjevec was recorded in 1960s and it continues until today. According to MIHALINEC et al. (2002) the landslide body consists of Pliocene – Pleistocene and Upper Miocene sediments with sliding surface at approximately 12 m of depth in zone of contact between two mentioned types of sediments. The aim of this paper is to represent a mineralogical composition of sediments from Črešnjevec landslide to see whether or not a mineralogical composition, especially clay minerals, has an influence on physical and mechanical properties of landslide sediments making them sensitive to sliding. Because of different environmental conditions during the Pleistocene and Upper Miocene periods (KOVAČIĆ & GRIZELJ, 2007 ; GRIZELJ et al., 2017), it was expected that the mineral composition would be also different. Furthermore, it was assumed that samples from shear zone would contain expandable clay minerals and high values of Atterberg limits and external specific surface area. Mineralogical and geotechnical analysis were conducted on 15 samples collected from Črešnjevec 35 m deep borehole drilled in 2016. during the project of Detail Engineering Geological Map of Podsljeme urbanized area M 1:5000 – Phase II (MIKLIN et al., 2016), in which three types of sediments were recognized: (a) heterogeneous Pleistocene sediments, (b) red sandy clays of presumed Upper Miocene- Pliocene age and (c) silts and sandy silts of Upper Miocene age. Atterberg limits were determined according to ASTM D 4318 – 10 (2010) standard proceeding. Residual shear strength parameters was obtained with standard direct shear test procedure. Specific surface area (SSA) was calculated from the Kozeny – Carman equation for hydraulic conductivity (URUMOVIĆ & URUMOVIĆ, 2016). Qualitative mineralogical analyses were performed by X-ray powder diffraction on random mounts of bulk samples and oriented mounts of < 2 μm fraction. Oriented mounts of the < 2 µm fraction were record after the following treatments: a) air drying, b) saturation with K+, c) solvation of K+ saturated mounts with ethylene-glycol, d) saturation with Mg2+, e) solvation of Mg2+ mounts with glycerol, f) heating to 400°C and g) heating to 550°C. Semiquantitative mineral composition of samples was obtained based on interpretation of bulk diffraction patterns and data processing in “RockJock” quantification program (EBERL, 2003). The main differences among all three sediment units are in carbonate and clay minerals content. Namely, heterogeneous Pleistocene sediments consist mostly of vermiculite, feldspars and quartz which are the main minerals in samples. Other mineral components in this unit are kaolinite, micas (illite and muscovite), goethite and amphiboles. Silts and sandy silts of Upper Miocene age consist mainly of quartz and micas in various quantitative ratios. They are in association with feldspars, carbonate minerals (dolomite, calcite), chlorite, smectite, kaolinite and goethite. Red sandy clays consist predominantly of quartz and micas in association with kaolinite, feldspar, goethite and small amount of vermiculite. Three of all samples match a shear zone with sliding surface. One of them is from units of heterogeneous Pleistocene sediments and other two from unit of red clays. They all have high clay content (38-76 %). The following mineral phases were detected in fraction < 2 µm: kaolinite, mica and two types of vermiculite (one with diffraction maximum on 18 Å and other with diffraction maximum on 14.5 Å, after solvation of Mg2+ mounts with glycerol). Furthermore, these samples have the highest values of liquid limits (41-86 %) and plasticity index (22-49 %) as well as SSA (60- 126 m2/g) and very low residual shear strength parameters (cr1=7 kNm-2, cr2= 6 kNm-2, φr1=13.5°, φr2=11.2°). According to obtained results it can be concluded that clay mineralogy, as a result of different sedimentation conditions, obviously had great influence on formation of sliding surface.

In the frame of RECALL project (Resilient European Communities Against Local Landslides), co - funded by the European Commission Directorate – General Humanitarian Aid and Civil Protection (DG ECHO) the soil instabilities of a secondary school was studied. The school is located in the city of Vukovar, on the right bank of Danube River, on the morphologically exposed ridge. After the building renovation in 1999 the first cracks on the school walls have been observed in 2004. Recently cracks on the school walls opened up to several tens of millimetres. After the comprehensive geotechnical surveys the first remedial measures were partly implemented in 2008, but they didn’t solve the problem of subsidence. The grounds as well as the entire ridge are composed of a fine-grained (silt size), homogeneous, highly porous, slightly coherent aeolian sediments - loess. Due to specific physical and chemical characteristics loess is usually very susceptible to collapse. Geotechnical properties of loess material mostly depend on the changes in water content. Therefore, the presence of water in loess sediment is considered as the main triggering factor for the observed ground subsidence. Grounds around object are soaked by several water sources. As an essential short-term mitigation measure the continuation of displacements and groundwater monitoring and the overall water drainage are recommended, while the subsequent remedial measures should be focused to the foundation stabilization by the deep micro-pilots into the intact sediment.

Razni subjekti, od županija, gradova i velikih javnih poduzeća, do privatnih osoba, susreću se s pitanjima vezanim za tehničke značajke i procjenu cijene koštanja sanacijskih radova na terenima zahvaćenim procesima klizanja. Da bi se destabilizirani teren sanirao, redovito je potrebno provesti geotehničke istražne radove, izraditi projektnu dokumentaciju za sanaciju destabiliziranog terena, izvesti radove sanacije i provesti praćenje njihove uspješnosti. U kompletnom procesu, izvedba građevinskog dijela radova sanacije, predstavlja najznačajnije financijsko opterećenje. U radu se daje prikaz na koji način se uz minimalno učešće geoloških i geomehaničkih radova i uz korištenje postojećih podataka i podataka koji se dobivaju vizualnim pregledom terena, izrađuje elaborat u kom se daju pretpostavke o uzrocima destabilizacije i prognoze o primjenjivim tehničkim rješenjima sanacije. Na osnovu tih podataka procjenjuje se cijena i vremensko trajanje pojedinih aktivnosti. Ovakav dokument predstavlja vrlo vrijednu osnovu zainteresiranima za planiranje budućih aktivnosti. Daje im uvid u radnje koje je potrebno poduzeti, prognozu vremena trajanja i red veličine cijene svake od njih.

U cilju utvrđivanja stabilnosti padina u prirodnim uvjetima na području Grada Zagreba, a za potrebe kvalitetnog planiranja i gradnje, u tijeku je provedba geotehničkih istražnih radova i izrada detaljne inženjerskogeološke karte Podsljemenske urbanizirane zone Grada Zagreba (DIGK–Faza II). Prva faza istraživanja (DIGK–Faza I) dala je detaljan pregled naslaga u dvije dimenzije (2D) i prikazana je na detaljnim inženjerskogeološkim kartama. Osnovni radovi koji se izvode u drugoj fazi su dubinska istraživanja radi pridobivanja podataka u trećoj dimenziji prostora (3D). Istraživanjima se utvrđuje debljina pokrivača ili površinske zone trošenja te geološki, inženjerskogeološki i geomehanički sastav pokrivača/površinske zone trošenja. Istražni radovi su bazirani na izvedbi geotehničkih istražnih bušotina, uz učešće geoloških, geomehaničkih i geofizičkih istraživanja te pratećih laboratorijskih ispitivanja. Metode i postupci istraživanja za navedene vrste radova detaljnije su opisani u članku, te je dan i komentar na očekivane i dobivene rezultate, kao i daljnje preporuke.

Mjerenjem mikroseizmičkog nemira mogu se dobiti osnovne informacije o građi površinskih slojeva odnosno mogu se prikupiti podaci koji mnogo govore o odzivu i tipu lokalnoga tla na pobudu potresnim valovima, te olakšavaju klasifikaciju tla u skladu s građevinskim propisima ili normama, npr. prema Eurokod 8, Tablica 1 (HZN 2011a, 2011b ; HERAK et al., 2013). U sklopu seizmičkog mikrozoniranja za potrebe grada Zagreba provedeno je i inženjerskogeološko mikrozoniranje prema standardima Eurokoda 8 za zapadni dio Podsljemenske urbanizirane zone. Glavne karakteristike površinskih naslaga prema Eurokodu 8 određene su u odnosu na seizmičku osjetljivost (A, B, C, D, E, S1 i S2). Prema inženjerskogeološkim karakteristikama površinskih naslaga na području istraživanja A tip tla bi predstavljali uglavnom dolomiti trijasa, vapnenci i vapneni lapori miocena, B tip tla bi predstavljali mješavina materijala vrlo zbijenog pijeska, šljunka ili vrlo čvrste gline, debljine najmanje nekoliko desetina metara, uglavnom miocenske starosti, C tip tla bi predstavljali slojevi zbijenog ili srednje zbijenog pijeska, šljunka ili čvrste gline, debljine od nekoliko desetina do više stotina metara uglavnom miocenske i kvartarne starosti, D tip tla bi predstavljali rastresiti do srednje zbijeni nevezani sedimenti (s ili bez mekanih kohezivnih slojeva) ili predominantno mekano do čvrsto kohezivno tlo uglavnom miocenske starosti, te E tip tla bi predstavljali aluvijalni nanosi sa vrijednosti Vs30 prema tipu C ili D i debljinom između 5 i 20 m, ispod kojeg je krući materijal sa vs30 > 800 m/s. Na području istraživanja taj tip naslaga prisutan je samo na manjem dijelu. Također su izdvojena i klizišta prema DIGK-Faza I (MIKLIN et al., 2007 ; MIKLIN 2011), odnosno ovaj „tip tla“ (S1, S2) je podložan likvefakciji s osjetljivim glinama ili predstavlja bilo koji drugi profil tla koji nije uključen u kategorije A-E. Većinom se radi o bubrećim glinama zbog kojih je nastalo klizanje različitih stratigrafskih članova, ali je najveći postotak klizišta u naslagama kvartarne i miocenske starosti. Rezultati provedenih istraživanja sintetizirani su u kompilacijsku kartu seizmičkog mikrozoniranja za istraživano pilot-područje (HERAK et al., 2013). Kako je riječ o integriranju vrlo različitih podataka širokog spektra, mogućnost posve objektivne analize i interpretacije je bila vrlo teška, pa je bilo nužno i donekle subjektivno odlučivanje o tome koji tip tla pridijeliti kojoj od zona identificiranih inženjersko geološkim mikrozoniranjem. Dobivena „pojednostavljena“ karta seizmičkog mikrozoniranja se može primijeniti u urbanom planiranju, osim na izdvojenim područjima identificiranih klizišta, gdje su potrebna dodatna istraživanja.

One of a key point in the investigation and interpretation of landslides is the role of mineralogical and geochemical composition of sediment in physical and mechanical properties of soils, as well as its influence on sensitivity of landslide material to swelling and sliding. The objective of this paper is to present a mineralogical composition of sediments from the Kostanjek landslide area, aimed at interpretation of influence of its mineralogical and geochemical composition to sliding and swelling processes, especially regarding to clay minerals species like smectite clays. The analyses were performed on 17 samples collected from 100 m deep borehole B-1 drilled in the central part of the Kostanjek landslide in which the four lithological groups differ: engineering soil (Quaternary) ; massive marls (Upper Pannonian) ; marls intercalated with limestone, (Lower Pannonian) ; thinly laminated marls, also known as “Tripoli” sediments or tripolite (Lower Pannonian – Sarmatian). Samples K1 – K3 represent engineering soil, coarse to fine grained. Samples K4 – K11 represent massive marls while sample K12 represent the marls between limestone intercalations. Samples K13 – K17 represent thinly laminated clays recognized in two forms: flat laminated and wavy laminated. The analysis was performed by X-ray powder diffraction method on random and oriented mounts of air dried material, after glycol treatment and heating to 400˚C and 550˚C. The results of x-ray diffraction analyses represent a bulk composition of each sediment group. Predominant are sheet silicates, followed by carbonates and quartz. Dolomite and pyrite occur in some samples at trace levels. Among clay minerals the most abundant is smectite component (50–70 w%) which is susceptible to swelling. Namely, because of its characteristic structure, in interaction with circulating solution in soil, smectite clays increase the volume of crystal lattice and thus have a negative impact on shear strength parameters, which can result in the appearance of swelling or sliding.

Data about landslides at the hilly area of the Zagreb city (Podsljeme area), was systematically collected three times in last 50 years. In this paper three geomorphological historical landslide inventories are shortly presented together with framework studies ordered by local City government aimed at landslide risk management. Quantitative comparison of inventories was made by comparing main characteristics of landslide maps and size of recorded landslides. Examples from certain locations were also selected to show overlapping of mapped landslide contours. It is evident that, despite using the same landslide identification method, landslide contours in all three inventories vary significantly primarily as a consequence of subjectivity of interpretations inherent to identification of landslide borders by reconnaissance ground surveys in large scale.

The importance of landslide inventory or geotechnical inventory is recognized on the European level. As of July Croatia is becoming a member of European Union so it would be preferable that the data about existing landslides are in accordance with European Union data. In that sense a questionnaire form was submitted in 2010 to all European countries. Aim of this questionnaire was a review of landslide data and their state within SafeLand project – Living with landslide risk in Europe: Assessment, effects of global change and risk management strategies. The main activities of SafeLand project is to: improve assessment of landslide hazard (triggering mechanisms and runout), quantitatively assess landslide risk in selected areas of Europe, assess the changing pattern of landslide risk as effects of climate change and other factors, verify estimated hazards through monitoring and remote sensing and to design and test the possibilities of early warning systems and risk management with development of toolbox for landslide risk mitigation (measures and choosing the appropriate risk mitigation strategy). Project team is assembled from 25 institutions from 13 countries with the leadership of Norwegian Geotecnical Institute (NGI). Some European countries have already developed advanced data collection about landslides but in the majority of the countries this process is still in development. Many European countries are working on their national or at least regional data basis (Landslide data basis – LDBs). There are still some difficulties in unifying these data as their exact content, data up dating methods, form, structure, language and availability differs in wide range. In Croatia registration of landslides is an ongoing process within production of engineering geological maps. Engineering geological map in scale of 1:300.000 is finished but sheets of basic engineering geological maps in scale of 1:100.000 are not. It would be preferable to have data even in some more detailed scales but those kind of data only exists for some urbanized areas (for example Detailed engineering geological maps in scale of 1:5.000 for area of Zagreb or only for some specific locations within different types of reports and investigations). For the needs of SaleLand the existing accessible data about landslides were reviewed and some interesting patterns about landslide number, distribution and type can be seen, on national (regional) level. The main geological differentiation in Croatia is on two regions: panonian region and karst region. Panonian region stretches from eastern part of Croatia (Slavonia) to the middle part of Croatia (to the city of Karlovac). Karst region stretches from the middle part of Croatia (south from the city of Karlovac) with coastal part (Istria from west and Dalmatia on east). Geological differentiation is mainly in accordance with climate differentiation: continental and maritime. In these main regions some micro regions can be distinguished. For every micro region the main type of mass movement is different and a characteristic model can be developed. Based on the available date, these characteristic models, for every micro region will be presented and explained. The emphasis is on incorporating these models into one national up to date landslide data base in accordance with the goals of Safeland project.

The term landslide comprises almost all varieties of mass movements on slopes. Landslide inventory contains data about landslides on certain area. Landslide inventory map shows the locations of the landslides and can contain other additional data. Landslide maps can be prepared using different techniques. Landslide inventory maps are usually used in determination of landslide mitigation measures, civil engineering and urban planning. Spatial distribution of landslides and their activity is subject of change during time and that is a reason for development of landslide inventory maps from different periods (can be done by stereoscopic analysis of photographs from different periods). Data in landslide inventory is one of the most basic and most needed in further analysis in landslide susceptibility, landslide hazard and landslide risk. Most widespread and most used method in landslide inventory development is geomorphological mapping of terrain and usage of different methods of remote sensing (for example stereoscopic analysis). Even today, use and stereoscopic analysis of aerial photography has defined a prevailing standard and a benchmark against which new technologies to detect and map landslides are compared. Analytic hierarchy process (AHP) is a structural technique for data organization and analysis used for obtaining complex decisions. AHP can be used practically in landslide mapping and assessment of characteristic landslide features. Stereoscopic analysis was used in combination with AHP methodology for the assessment of characteristic landslide features on the southern slopes of the Mt. Medvednica. Assessment of characteristic landslide features for the identified landslides was based on the visible landslide features on photography (stereoscopic analysis), which included assessment of: landslide features (features at landslide body, features of landslide body boundary and features at main scarp) and features at landslide body toe part, slope morphology and land cover. Identified landslides were classified based on visible landslide features and according AHP score. Investigation encompassed: (i) criteria development for application of AHP methodology in area of research (100 km2), (ii) interpretation of 130 aerial photos of two generations, (iii) landslide inventory development and preparation of landslide inventory map and (iv) methodology verification on the basis of comparison with existing data and field check. In the paper some characteristic examples of identified landsides on the southern slopes of the Mt. Medvednica determined by stereoscopic analysis are given, with AHP score and field report. The methodology presented in this paper (stereoscopic analysis in combination with AHP methodology), is used for the first time in Croatia in landslide inventory development and preparation of landslide inventory map. Also the methodology and the established criteria is applicable in landslide inventory development and preparation of landslide inventory map in other areas where landslides exists in same or similar conditions, in Croatia or worldwide. Since there is no uniform landslide inventory for the whole territory of Croatia, the used methodology and the developed criteria also can be used as guidelines for the usage of remote sensing in landslide inventory development on national level.

One of key point in the investigation and interpretation of sliding and swelling phenomena in nature materials is the role of mineralogical composition on physical and mechanical properties, especially regarding clay minerals. Therefore detailed investigations of the mineralogical composition of Kostanjek landslide sediments were conducted. The Kostanjek landslide is the largest landslide in MedvednicaMt. hilly zone placed in the residential area of the City of Zagreb. It was activated in 1963 due to massive blasting in the Bizek Quarry and excavation in a marl quarry at the foot of the hill. Unlike to all other landslides in Medvednica Mt. hilly zone which are mostly small shallow landslides, the Kostanjek landslide is an atypical, deep-seated large translational landslide with multiple (re)activations of landslide bodies (Ortolan, 1996 ; Mihalić Arbanas et al., 2013). Except sliding, in the area of the Kostanjek landslide there are evidences of subsidence and bulging of ground surface that might be associated with the processes of swelling. This phenomenon is usually noticed after the periods of heavy rain or dry summer. Kostanjek landslide is also one of the pilot areas in the frame of the Croatian – Japanese SATREPS FY2008 joint research project on “Risk Identification and Land – Use Planning for Disaster Mitigation of Landslides and Floods in Croatia” (Krkač et al., 2011). According to historical data, the mineralogical analyses of Kostanjek landslide sediments were performed by Balen (1975) and Slovenec (1989) but only on the samples from the marl quarry. In the frame of scientific activities of the Croatian – Japanese project, one 100 m deep borehole was drilled in the middle part of the Kostanjek landslide in 2012. The core inspection revealed four lithological units as follows: (1) engineering soil of Quaternary age (0 – 10 m), (2) Upper Pannonian massive marls (10 – 45 m), (3) Lower Pannonian marls intercalated with limestone (45 – 60 m) and (4) Sarmatian thin laminated marls (60 – 100 m). For the purpose of mineralogical analyses a total of 17 samples were collected, several from each unit. The samples was analysed by X-ray powder diffraction method on random and oriented mounts after certain treatments. Based on interpretation of X-ray diffraction patterns a quantitative mineral composition (w%) of whole rock was obtained and a semi quantitative content of clay minerals were also determined, among which the most abundant were smectite clays (Martinčević et al., 2012). It is well known that clay minerals have a main role in the processes of swelling, especially those from smectite group (Grim, 1968). To verify the results obtained by x – ray diffraction the method of visible and near – infrared (VIS-NIR) spectroscopy was used. The operating principle of the method is based on sending light onto the sample and then measuring the light which is reflected back from the sample. Frequencies which are absorbed appear as a reduced signal of reflected radiation. The measured wavelength region ranges from 380 – 2500 nm which mean that covers a visible (400-700 nm) and near- infrared (700-2500 nm) regions. The spectral patterns include overtones and combination bands that occur from chemical bonds within soil minerals (Viscarra Rossel et al., 2009 ; Stenberg et al., 2010). Analysis were performed in laboratory, on the above mentioned core samples using a portable Terraspec Explorer spectrometer. The interpretation of results was based only on qualitative description of spectral patterns (Fig. 1). A special attention was given to the samples from the first two units (0-20 m) which are placed in unsaturated zone. Before the scanning, samples were dried on the air and grinded to the fraction less than 2 mm. As a result of the samples drying the effect of natural moisture should be negligible. The most common minerals in the clay fraction are smectite, kaolinite and muscovite. Smectite has two very strong water bends near 1400 and 1900 nm from molecular water and another at 2200 nm. Kaolinite is an aluminium silicate with strong reduced signal near 1400 nm due to OH stretch, and near the 2200 nm due to the combination of OH stretch and Al-OH bend. Samples from first, second and fourth unit have in spectral pattern the large reduced signal near 1400 and 1900 which were associated with molecular water in clay minerals. In spectral pattern of samples from third unit this signal is smaller than in other samples. Based on these results, it can be concluded that, for some reasons, the clay minerals incorporated less water molecules in their crystal lattice. The reduced signals near 2200 nm are constant through the spectral patterns of all samples. According to the other reduced signals a presence of iron oxides and oxyhydroxides (near 900 nm) and calcite component (2330 nm) was identified. As expected, the identification of soil mineral composition by VIS- NIR spectroscopy was in general with good agreement to the results obtained by X-ray diffraction.

Location of new deep structural borehole was planned with aim to cover all lithostratigraphical units, from the youngest to the oldest one. According to preliminary geological profile, made for the purpose of Detailed Engineering Geology Map of Podsljeme Urban Area in scale of 1:5000, the thicknesses and depths of sediments were estimated as follows: Quaternary sediments (Q1) on 45 m, the upper part of Upper Pontian sediments (2M7) on 60 m, the lower part of Upper Pontian sediments (1M7) on 145 m, the Lower Pannonian sediments (M61) on 160 m, the Upper Pannonian (M62) sediments on 20 m, sediments of Sarmatian (M5) on 20 m and of Badenian (M4) on 110 m. The real thicknesses of deposits were measured after drilling and they differ in some way from those that have been estimated. Core inspection revealed all litostratigraphic units mentioned above, but with different thicknesses: Qaternary sediments with 10.2 m, the upper part of Upper Pontian sediments with 42.8 m, the lower part of Upper Pontian sediments with 127.0 m, the Lower Pontian sediments with 50.0 m, the Upper Pannonian sediments with 86.3 m, the Sarmatian sediments with 14.7 m and Badenian sediments with thickness of 19.0 m. Quaternary sediments are characterized by alteration of clayey silts and silts enriched on Fe-Mn concretions. At the depth of 9.6-10.1 m a presence of quartz pebbles was noted. The contact with sediments in the base is sharp and erosional. Similar sediments were found in the wider area of Medvednica hilly zone and their stratigraphical position was based on the analyses of pollen content. The upper part of Upper Pontian sediments is represented by yellowish to reddish brown and grey to dark gray clayey and silty sands. They are enriched on micas, and in places with Fe-Mn concretions. Within a certain intervals limonite (28.1-28.2 m) and calcite crust (13.0-16.6 ; 33.5-33.7 m) were noted. These sediments are usually horizontally laminated, but in places they are massive. They belong to the environment of delta which intruded into the shallow brackish lake. Stratigraphical age has been determined on the basis of fossils among which the most abundant were molluscs and ostracods. According to the name of most abundant mollusc, these sediments are also known as the “Rhomboidea deposits”. Lower part of Upper Pontian sediments is composed of silts rich with calcite and silty marls with typical grey or greyish colour. They are mostly massive although at the end of this interval they are characterized with horizontal bedding and in alteration with thin layers of sands. They are the result of sedimentation which took place in border conditions, deep to the shallow environment. Sedimentation circumstances were proved by the existence of certain macro and microfossils. At the boundaries between Lower Pontian and Upper Pannonian there are transition deposits which consist of dark gray massive marls. They were deposited in deep, brackish lacustrine environment and contain a rare plant particles and shell fragments. Sarmatian deposits are characterised as medium sorted grainstone. Except carbonates, the presence of quartz, quartzite and cherts with numerous fossil particles (benthic foraminifera, fragments of seaweeds, ostracods, molluscs, shells, etc.) was noted. A detailed mineralogical analysis revealed a large amount of smectite clay minerals. As a result of their specific crystal structure they are very sensitive to shrinking and swelling. Badenian sediments are represented with heterogeneous lithotamnium limestones which are predominantly composed of peloids with presence of biofragments, such as: shells of molluscs, ostracods, particles of seaweed and benthic foraminiferas. The size of the fragments is between 0.2-0.4 mm. Limestones are poorly sorted, recrystallised with micritic to microsparitic matrix. New structural borehole revealed real thicknesses of geological units and this new data is important in better understanding of the geological structure of Medvednica hilly zone.

Research area covers about 10 km2 and it is located on the southern slopes of Dilj mountain (Croatia) and belongs to its foothill. For this area are prepared new geological (M 1:5000) and engineering-geological map (M 1:5000) showing landslides and gullies. Also, a landslide inventory with 60 registered type of instability was prepared. On the field, samples for laboratory tests were taken. Purpose of research was to categorize the terrain on the bases of stability which enables making of optimal urbanistic plan.

Within the Croatian-Japanese international project ‘Risk Identification and Land-Use Planning for Disaster Mitigation of Landslides and Floods in Croatia’ there are three working groups. Activities of Working Group 3 (WG 3) are related to landslide mapping. The main project activities of WG 3 at the area of the City of Zagreb are aimed at development of landslide inventory and landslide hazard mapping in the hilly area of Mt. Medvednica. The final objective of the scientific joint research is the development of risk mitigation measures that can be instituted through the system of urban planning and civil protection in the City of Zagreb. Dissemination and use of the results should ensure significant benefits for the local and regional communities that are directly and indirectly threatened by landslides. Aerial photo interpretation of landslides for the purpose of landslide inventory mapping in the area of the City of Zagreb was carried out by using stereo pairs from different periods. As first set of aerial photos, were used photos of Zagreb hilly area from 1962. As a cross check of the obtained data aerial photos from 1998 were used. For this interpretation of aerial photos and a landslide inventory preparation the criteria was setup in a sense of geomorphological properties of various morphological forms (slope’s inclination, curvature, direction, position, etc. with curtain accuracy). Interpreted landslides and data about them were organized in a GISdata base. In the data base there are data about: location, geology, geometry, landslide boundary, relative position at slope, features at main scarp, features in landslide body, landslide body toe, vegetation at landslide area, potential of instability and landslide type. The result of interpretation of these photos was compared with historical data from two sources: landslide inventory map from 1979 which was used in urban planning for the City of Zagreb ; and landslide inventory map from 2007 which is currently in use in urban planning for the City of Zagreb.

Basic Engineering Geological Map of Croatia in scale of 1:300000 is completed by Croatian Geological Survey (CGS) as a scientific project financed by Ministry of Science, Education and Sport. The second phase of this project is production of the Basic Engineering Geological Maps in scale of 1:100000 for entire Croatia. These maps are made by standardized methods and integrated approach which includes usage of the existing data and new data incorporated in the geographic information system.

The sinkholes are considered as morphological indicator of the karstification intensity. Croatian sinkhole inventory is based on the recognition and manual digitalization of the sinkholes at 1:25000 scale topographic maps. From point features, sinkhole density map is derived and overlapped with lithostratigraphical units, major faults and general morphology of the area, using ArcGIS software.

Pruga od Zagreba do Josipdola dionica je brze pruge od Zagreba do Rijeke. Dionica je podijeljena na dvije poddionice od Zagreba do Karlovca i od Karlovca do Josipdola. Od Zagreba do Karlovca predložena su tri varijantna rješenja, a od Karlovca do Josipdola dva varijantna rješenja. Zavisno od varijante ukupna duljina trase iznosi od 81 do 84 km. Na trasi dominantna su dva tipa terena: nizinski - vezan za aluvijalne nanose rijeka i brdoviti krški teren - pretežno izgrađen od vapnenaca i dolomita. Zadatak inženjergeologa bio je prikazati inženjerskogeološka svojstva naslaga, kako bi se projektant što lakše opredijelio za varijantu trase koja je ekonomski najopravdanija.

Rad ukazuje na iznenadnu pojavu glinovitog materijala u tunelu, premda je prema prognozi tunel u cjelosti trebao biti izveden u vapnencu.

Prikazane su geološke značajke naslaga duž ceste Dubrovnik–Debeli brijeg, dužine 42 km. Na temelju vodopropusnosti naslaga i njihove hidrogeološke funkcije teren je kategoriziran - obzirom na rizik od onečišćenja pitke vode i mora izdvojene su zone visokog, umjerenog i umjerenog/niskog rizika. Uzak prostor, blizina državne granice i nepovoljne geološke odlike terena primoravaju projektanta da trasu ceste "vodi" visoko u zasjeku duž strmca navlake. Izdvojene su 3 inženjerskogeološke sredine: zbog položaja u čelu navlake razlomljen i okršen karbonatni slijed naslaga, kompleks flišnih naslaga podložan eroziji, jaružanju i generiranju klizišta i siparišne naslage kvartara.

Nastanak ponikava obično se veže uz postojanje razlomljenih zona, cirkuliranje vode kroz te zone, te kemijsko i mehaničko trošenje. Iako su navedeni čimbenici najvažniji postoje i drugi, a neki od njih su razmatrani i u okviru ovog rada. To su stratigrafska pripadnost, nagib padine, nadmorska visina, litologija, te udaljenost od glavnih rasjeda.

Osnovna inženjerskogeološka karta list Ivanić Grad je kompilacijska karta sastavljena od tri faktorske karte: od Osnovne geološke karte, Osnovne hidrogeološke karte i karte klizišta i erozije mjerila M1: 100 000. Dvije dodatne karte seizmotektonska karta i karta s kategorijama terena po stabilnosti su mjerila 1: 300 000. Osim karte klizišta i erozije inženjerskogeološka karta obuhvaća cijelu lepezu inženjerskogeoloških članova i kompleksa. Tako da se na listu nalaze kompleksi čvrstih, slabo očvrslih, i klastičnih stijena, te koherentnog i nekoherantnog tla.

Kostanjek landslide is placed in the hilly area of Mt. Medvednica, which belongs to western part of urban area of Zagreb city. This is the largest landslide in the area of Zagreb mainly caused by antropogene factor, i.e. mining of limestone and marl. Open pit mines are placed in the vicinity of upper part of landslide and in the lower part of landslide. Kostanjek landslide was activated in 1963 and excavation of marl was stoped in 1988 after identification of surface excavation in the toe of landslide as the triggering factor. Interpretation of landslide model and landslide causes was made by Ortolan (1989). Main elements of landslide model developed by Ortolan (1989) are the following: landslide area is 1.2 km2 ; total volume of displaced mass is 32.6 millions m3 ; three sliding surface are interpreted (at the depths 50 m, 65 m and 90 m) ; landslide is reactivated in the period of 26 years ; volume of second displacement was 12.8 millions m3 ; volume of third displacement was 7 millions m3. Initial displacement occurred along bedding planes of Sarmatian deposit composed of laminated marl. Subsequent reactivation was in upper part of landslide body composed of deposits of Panonian age (marl and clayey marl). Maximum displacement of particular parts at the landslide surface (in the period from 1963 to 1994) was 3.9 m. Consequently, landslide damaged approximately 500 residential and industrial buildings, and 100 of them are completely destroyed. Kostanjek landslide area is highly risky area because of existing and potential damages. Because of that, the City of Zagreb ordered design of remedial measures which is currently in progress. In the frame of Croatian-Japanese project, Kostanjek landslide is pilot area for establishment of integrated monitoring system using geodetic and geotechnical monitoring equipment (GPS, extensometers, inclinomteres, piezometers, pore pressuremeters, rain gauge, seismographs). Real time monitoring results will be base for establishment of early warning system. For the purpose of detailed planning of monitoring system it is necessary to define landslide border at the surface. In the case of Kostanjek landslide, landslide border is not clearly expressed. Moreover, damaged houses also exist outside landslide border interpreted by Ortolan (1989). Considering existing data and requirements of planned monitoring activities it is necessary to establish inventory of existing damages on houses and constructions in the form of GIS database.

Klasičnim kartiranjem utvrđeno je 707 klizišta i izračunato opterećenje klizištima na kvadratičnoj mreži od 1km2. U centar svakog kvadrata upisana je vrijednost opterećenosti klizanjem, izolinijama su spojene iste vrijednosti i tako je dobivena preliminarna karta hazarda od klizanja.

Inženjerskogeoloske uvjete geološkog okolišta potrebno je interpretirali trodimenzionalno za cijelo istraživano područje a zatim i prikazali inženjerskogeološkim modelom. S razvojem informacijske tehnologije, pojavljuje se trend 3D modeliranja u geologiji. Najveći problem modeliranja u inženjerskoj geologiji predstavlja to što ne postoji nekakava općeprihvaćena procedura za takav postupak, niti za to razvijen softver koji bi zadovoljavao u svim segmentima. Svrha ovog rada je razvijanje postupaka 3D modeliranja (inženjerskogeološkog) u specijaliziranim softverima za primjenu u inženjerskogeološkom istraživanjima pojedinačnih lokacija, na primjeru klizišta Struga Banska. Pri izradi inženjerskogeološkog 3D modela klizišta Struga Banaka - Unčani, glavnina je posla obavljena pomoću softvera Rhinoceros. Na kraju je utvrđeno da je postupak dobivanja 3D inženjerskogeološkog modela za određenu lokaciju uglavnom uvijek isti. Kao prvo treba sakupiti postojeće podatke i procijenili da li su nam ti podaci dovoljni za dobivanje valjanog modela. Ako se raspolaže dovoljnom količinom adekvatnih podataka drugi korak je preoblikovanje podataka u oblik koji će bili razumljiv softveru u kojem namjeravamo izraditi model i unos tih podataka. Treći korak je samo modeliranje i ispravljanje eventualnih nepravilnosti, te zavisno prema potrebi i nadopuna rezultata/modela i pomoću drugih softvera.

Ovaj rad opisuje kako se u području geologije odnosno inženjerske geologije mogu pronaći odgovori za rješavanje nekih problema vezanih uz odlaganje otpada poput određivanja pogodnih lokacija za odlagališta primjenom geološkog zoniranja ili određivanja uvjeta i kriterija koje odlagališta ili pojedini njegovi konstruktivni elementi moraju zadovoljiti u određenom geološkom okruženju. Pri izvedbi odlagališta ne treba zanemariti ekonomsku stranu problema, a poznavanjem geološkog okruženja i iskorištavanjem geoloških pogodnosti na određenim lokacijama omogućuju se uštede pri izgradnji, te smanjuje mogućnost zagađenja naknadno. Karte IG-zoniranja daju potpuniju sliku o svakoj izdvojenoj jedinici, a u Hrvatskoj bi se za njihovu izradu mogli koristiti neki već ranije objavljeni podaci uz nužne nadopune u određenim povoljnim područjima, gdje bi trebalo provesti detaljnija i ciljana istraživanja vezana za problematiku odlaganja otpada.