László Podolszki, doktor tehničkih znanosti

László Podolszki defended his doctoral thesis Stereoscopic analysis of landslides and landslide susceptibility on the southern slopes of the Medvednica Mt. at the Faculty of Mining, Geology and Petroleum Engineering, University of Zagreb, Croatia on May 12, 2014. The committee for Defence included Assist. Prof. Dr. Dario Perković, Faculty of Mining, Geology and Petroleum Engineering, University of Zagreb, chairman; Prof. Dr. Snježana Mihalić Arbanas, Faculty of Mining, Geology and Petroleum Engineering, University of Zagreb, Prof. Dr. Željko Arbanas, Faculty of Civil Engineering, University of Rijeka, Assist. Prof. Dr. Davor Pollak, Faculty of Mining, Geology and Petroleum Engineering, University of Zagreb and Assist. Prof. Dr. Dubravko Gajski, Faculty of Geodesy, University of Zagreb. Prof. Dr. Snježana Mihalić Arbanas was the thesis supervisor.László Podolszki obranio je 12. svibnja 2014. na Rudarsko-geološko-naftnom fakultetu Sveučilišta u Zagrebu doktorski rad Stereoskopska analiza klizišta i relativne opasnosti od klizanja na južnim obroncima Medvednice. Doktorski rad obranjen je pred povjerenstvom u sastavu: doc. dr. sc. Dario Perković s Rudarsko-geološko-naftnog (RGN) fakulteta Sveučilišta u Zagrebu, izv. prof. dr. sc. Snježana Mihalić Arbanas s RGN fakulteta Sveučilišta u Zagrebu, izv. prof. dr. sc. Željko Arbanas s Građevinskog fakulteta Sveučilišta u Rijeci, naslovni doc. dr. sc. Davor Pollak s RGN fakulteta Sveučilišta u Zagrebu i doc. dr. sc. Dubravko Gajski s Geodetskog fakulteta Sveučilišta u Zagrebu. Mentorica je bila izv. prof. dr. sc. Snježana Mihalić Arbanas

László Podolszki, PhD in Technical Sciences

László Podolszki defended his doctoral thesis Stereoscopic analysis of landslides and landslide susceptibility on the southern slopes of the Medvednica Mt. at the Faculty of Mining, Geology and Petroleum Engineering, University of Zagreb, Croatia on May 12, 2014. The committee for Defence included Assist. Prof. Dr. Dario Perković, Faculty of Mining, Geology and Petroleum Engineering, University of Zagreb, chairman; Prof. Dr. Snježana Mihalić Arbanas, Faculty of Mining, Geology and Petroleum Engineering, University of Zagreb, Prof. Dr. Željko Arbanas, Faculty of Civil Engineering, University of Rijeka, Assist. Prof. Dr. Davor Pollak, Faculty of Mining, Geology and Petroleum Engineering, University of Zagreb and Assist. Prof. Dr. Dubravko Gajski, Faculty of Geodesy, University of Zagreb. Prof. Dr. Snježana Mihalić Arbanas was the thesis supervisor

Landslide types in the Slani Potok gully, Croatia

The Slani Potok gully (0.48 km2) is situated in the central part of the Vinodol Valley (64.57 km2) in Croatia, and it was formed in the Eocene flysch deposits. So far, the area of Slani Potok has been mainly referred in the scientific literature as being subjected to unusually intense soil erosion processes (i.e., ‘’excessive erosion’’), associated with landslides. However, the landslides were never investigated in detail, given the available research methods only involved field investigations. Therefore, the landslide types according to the most commonly used landslide classifications have remained undetermined. In this paper, landslide types in the Slani Potok gully are presented, identified and mapped based on the visual interpretation of seven different LiDAR topographic derivatives computed from the 1 x 1 m DTM available from March 2012. The geomorphological historical landslide inventory of the Slani Potok gully was created, consisting of 181 landslide phenomena. Landslides cover 69 % of the area (0.33 km2) of the Slani Potok gully. The size of the smallest landslide is 65 m2, and of the largest is 10,563 m2. Landslides are very small to moderate-small, shallow to moderate-shallow, and mainly successive in distribution. Most of the landslides initiate along the margins of the gully channel walls, and extend to the gully channel bottom. Such a large number of identified landslides, as well as their specific spatial arrangement within the gully, indicates that sliding processes predominantly affect the morphologic development of the Slani Potok gully, and that the soil erosion is the secondary process in the study area.</p

Application of innovative technologies in landslide research in the area of the City of Zagreb (Croatia, Europe)

This paper describes the application of innovative technologies for landslide detection, mapping and monitoring in the City of Zagreb since 2010. Airborne Light Detection and Ranging (LiDAR) data are used to visually identify landslides in the Podsljeme Zone over the area of 180 km2 for the purpose of landslide inventory mapping. The total number of landslides in the analyzed area (approx. 1,600 landslides) is estimated based on the average landslide density (9 landslides per square km) from the most reliable geomorphological historical inventory, which was produced in 1979. Examples of the visual interpretation of very-high-resolution bare-earth DEMs (Digital Elevation Model) are given to show the potential of these innovative techniques to identify the landslide contours of the very small, small and moderately small landslides that are characteristic of the study area, which is composed of engineering soils and/or soft rocks (marls). In the framework of the described landslide research, the biggest landslide in the Podsljeme Zone, the Kostanjek landslide (landslide area of 1 km2), was also equipped with an automated near-real time monitoring system that encompassed approximately 40 sensors to monitor landslide movement and landslide causal factors. Monitoring of this deep and large landslide during multiple extreme hydro-meteorological events from January 2013 to January 2015 enabled collection of data for the analysis of landslide movement on the surface and in the underground and as well as analysis of the relationship between landslide reactivations and its triggers, i.e., changes in groundwater level and precipitation. The final aim of the described scientific research in terms of landslide mapping and monitoring is its practical application in land-use planning and civil protection systems in the City of Zagreb. Namely, the conclusions propose reliable and efficient methods for landslide identification and monitoring, which are necessary to provide data and solutions for hazard and risk reduction to local authorities that are managed by the City

PROCJENA PODLOŽNOSTI NA KLIZANJE NA PODRUČJU GRADA KARLOVCA PRIMJENOM BIVARIJANTNE STATISTIČKE METODE

A preliminary landslide susceptibility analysis on a regional scale of 1:100 000 using bivariate statistics was conducted for the City of Karlovac. The City administration compiled landslide inventory used in the analysis based on recorded landslides from 2014 to 2019 that caused significant damage to buildings or infrastructures. Analyses included 17 geofactors relevant to landslide occurrence and classified them into four groups: geomorphological (elevation, slope gradient, slope orientation, terrain curvature, terrain roughness), geological (lithology-rock type, proximity to geological contacts, proximity to faults), hydrological (proximity to drainage network, proximity to springs, proximity to temporary, permanent and to all streams, topographic wetness) and anthropogenic (proximity to traffic infrastructure, land cover using two classifications). Five scenarios were defined using a different combination of geofactors weighted by the Weights-of Evidence (WoE) method, resulting in five different landslide susceptibility maps. The best landslide susceptibility map was selected upon the results of a ROC curve analysis, which was used to obtain success and prediction rates of each scenario. The novelty in the presented research is that a limited amount of thematic data and an incomplete landslide inventory map allows for the production of a preliminary landslide susceptibility map for usage in spatial planning. Also, this study provides a discussion regarding the used method, geofactors, defined scenarios and reliability of the results. The final preliminary landslide susceptibility map was derived using ten geofactors, which satisfied the pairwise CI test, and it is classified in four zones: low landslide susceptibility (57.05% of the area), medium landslide susceptibility (20.63% of the area), high landslide susceptibility (13.28% of the area), and very high landslide susceptibility (9.03% of the area), and has a success rate of 94% and a prediction rate of 93% making it a highly accurate source of preliminary information for the study area.Za grad Karlovac provedena je preliminarna analiza podložnosti na klizanje u regionalnome mjerilu 1 : 100 000 primjenom bivarijantne statistike. Inventar klizišta koji je korišten u analizama izradila je gradska uprava na temelju zabilježenih klizišta koja su izazvala znatne štete na zgradama ili infrastrukturi u razdoblju od 2014. do 2019. godine. Analize su uključivale 17 geofaktora relevantnih za pojavu klizišta podijeljenih u četiri skupine: geomorfološki (nadmorska visina, nagib terena, orijentacija padine, zakrivljenost terena, hrapavost terena), geološki (litologija, udaljenost od geološke granice, udaljenost od rasjeda), hidrološki (udaljenost od drenažne mreže, udaljenost od izvora, udaljenost od privremenih, stalnih i svih potoka, vlažnost terena) i antropogeni (udaljenost od prometne infrastrukture, namjena zemljišta primjenom dviju klasifikacija). Primjenom metode Weights-of-Evidence (WoE) definirano je pet scenarija, pri čemu su korišteni različiti geofaktori. Rezultati analiza čine pet različitih karata podložnosti na klizanje. Najbolja karta podložnosti na klizanje odabrana je na temelju rezultata analize ROC krivulje, koja je korištena za dobivanje stupnja točnosti i predikcije svakoga scenarija. Doprinos je prikazanoga istraživanja u tome da korištenje ograničenih tematskih karata i nepotpune karte inventara klizišta omogućuje izradu preliminarne karte podložnosti na klizanje za korištenje u prostornome planiranju. Također, ova studija pruža raspravu o korištenoj metodi, geofaktorima, definiranim scenarijima i pouzdanosti rezultata. Konačna preliminarna karta podložnosti na klizanje izrađena je korištenjem deset geofaktora koji su zadovoljili test pairwise CI i klasificirana je u četiri klase: niska podložnost na klizanje (57.05 % površine), srednja podložnost na klizanje (20.63 % površine), visoka podložnost na klizanje (13.28 % površine), vrlo visoka podložnost na klizanje (9.03 % površine), te ima stupanj točnosti od 94 % i stupanj predikcije od 93 %, što je čini vrlo točnim izvorom preliminarnih informacija za područje istraživanja

Mineralogical and Physical Properies of Typical Soils from Zagreb Podsljeme Area

Zbog specifične geomorfologije, složene geološke građe, te uslijed nagle i često neodgovarajuće izgradnje građevina, na području podsljemenske zone grada Zagreba prisutan je problem vezan uz stabilnost padina.Brojna klizišta predstavljaju prijetnju lokalnom stanovništvu i imovini. Na inženjerskogeološke uvjete u podsljemenskoj zoni najveći utjecaj imaju sitnozrnasta tla pleistocenske i gornjomiocenske starosti koja zauzimaju oko 70 % ukupne površine ovog područja. U okviru projekta „Detaljna inženjerskogeološka karta Podsljemenske urbanizirane zone M 1:5000 – FAZA I“ (skraćeno DIGK – FAZA I) provedena su istraživanja s ciljem utvrđivanja fizičko - mehaničkih svojstava tala u površinskom dijelu cijele podsljemenske zone do maksimalne dubine od 5 m, kao i dubljih profila tala na odabranim lokacijama. Istraživanja su obuhvaćala geomehanička ispitivanja i mineraloške analize. Analizom svih rezultata ispitivanjadobiven je uvidu vrste tala i njihovu relativnu zastupljenost u podsljemenskoj zoni s naglaskom na sitnozrnaste vrste tla te njihove sličnosti i razlike u odnosu na fizička svojstva, litostratigrafsku pripadnost ovisno o pripadnost i mineralni sastav.Due to the specific geomorphology, complex geological structures and as a consequence of quick and inadequate construction of buildings, there is a problem with the stability of the slopes in the Podsljeme area of Zagreb. The numerous landslides pose a threat to the local population and their property. The greatest influence on the engineering geological conditions in Podsljeme area have fine – grained soils which occupy about 70 % of total area. Within the framework of the project "Detailed engineering geological map of Zagreb Podsljeme area M 1: 5000 - PHASE I" (abbreviated DIGK – PHASE I), research was carried out to determine the engineering geological properties of soil in the surface area of the entire sub zone up to a maximum depth of 5 m as well as deeper profiles on selected locations. The investigations included geomechanical and mineralogical analyses. Based on the obtained data and their analyzes the authors represent a clear picture of the engineering soils in the Podsljeme area and their similarity and differences in relation to the physical and mechanical properties, the lithostratigraphic affiliation and the mineralogical composition

O VRSTAMA I PROSTORNOJ RASPODJELI KVARTARNIH NASLAGA SASTAVLJENIH OD FRAGMENATA KARBONATNIH STIJENA U VINODOLSKOJ UDOLINI, HRVATSKA – NOVE SPOZNAJE NA TEMELJU VISINSKIH LIDAR PODATAKA

The Vinodol Valley, situated in the north-western Adriatic in Croatia, is characterized by complex geological and morphological conditions. Palaeogene flysch deposits form the inner parts of the valley, while the steep valley flanks are composed of Cretaceous and Palaeogene carbonate rocks. Flysch bedrock is mostly covered by diverse Quaternary deposits, among which deposits originating from carbonate rock slopes are abundant. During previous investigations, based on conventional field geological mapping and mostly conducted in the north-western and central parts of the Vinodol Valley, such Quaternary deposits were addressed to the tectonic evolution of the study area and rockfalls, respectively. Therefore, they were generally named as Quaternary rockfall breccias, or Quaternary rockfall deposits. This study presents six types of the Quaternary deposits originating from carbonate rock slopes and their spatial distribution in the whole Vinodol Valley (64.57 km2 ), which are identified and mapped based on the visual interpretation of 1-m airborne LiDAR (Light Detection and Ranging) Digital Terrain Model (DTM). Lithological materials are classified according to engineering geological principles, and represent engineering formations. New insight into the types, shapes, geometric characteristics and hypsometrical positions of the identified sedimentary bodies indicate that some other gravitational mass movements, and not just rockfalls, played an important role in the formation of the Quaternary deposits originating from the carbonate rock slopes in the Vinodol Valley. This study also presents the potential of the visual interpretation of high-resolution LiDAR DTM for identification and mapping of superficial deposits in study areas characterized by complex geological and morphological conditions.Vinodolska udolina, smještena u sjeverozapadnome dijelu Hrvatskoga primorja, odlikuje se složenom geološkom građom i morfološkim uvjetima. Unutrašnji udolinski prostor izgrađuju flišolike naslage paleogenske starosti, a strmi bokovi udoline izgrađeni su od karbonatnih stijena kredne i paleogenske starosti. Padine izgrađene od flišolikih naslaga gotovo su u potpunosti prekrivene različitim vrstama površinskih naslaga kvartarne starosti, među kojima su obilno zastupljene površinske naslage sastavljene od fragmenata karbonatnih stijena. Tijekom prethodnih istraživanja, temeljenih na konvencionalnome terenskom geološkom kartiranju uglavnom u sjeverozapadnome i središnjemu dijelu Vinodolske udoline, ove su kvartarne naslage smatrane izravnom posljedicom tektonskoga razvoja istraživanoga područja, odnosno posljedicom pojava odrona, pa su općenito nazivane kvartarnim vapnenačkim brečama i kvartarnim naslagama odrona. Ovaj rad prikazuje šest vrsta kvartarnih naslaga sastavljenih od fragmenata karbonatnih stijena te njihovu prostornu raspodjelu na cijelome području Vinodolske udoline (64,57 km2 ), koje su identificirane i kartirane na temelju vizualne interpretacije digitalnoga modela reljefa (DMR) prostorne rezolucije 1 x 1 m izrađenoga od visinskih podataka prikupljenih laserskim skeniranjem iz zraka primjenom LiDAR tehnologije. Litološki materijali klasificirani su u skladu s inženjerskogeološkim principima i predstavljaju inženjerske formacije. Nove spoznaje o vrstama, oblicima, geometrijskim značajkama i hipsometrijskim položajima identificiranih sedimentnih tijela upućuju na to da su i neki ostali tipovi gravitacijskih pokreta, a ne samo odroni, imali važnu ulogu u formiranju kvartarnih naslaga sastavljenih od fragmenata karbonatnih stijena u Vinodolskoj udolini. Ovaj rad također prikazuje i mogućnosti primjene metode vizualne interpretacije DMR-a izrađenoga od visinskih podataka prikupljenih laserskim skeniranjem iz zraka primjenom LiDAR tehnologije za identifikaciju i kartiranje površinskih naslaga na područjima istraživanja obilježenima složenom geološkom građom i morfološkim uvjetima

VERIFIKACIJA POVIJESNIH INVENTARA KLIZIŠTA U PODSLJEMENSKOJ ZONI GRADA ZAGREBA S INVENTAROM KLIZIŠTA DOBIVENOGA IZ PODATAKA PRIKUPLJENIH LiDAR-OM

Data on landslide locations in the Podsljeme area can be found in three historical landslide inventory maps. Inventory maps from 1979 and 2007 are made based on geomorphological field mapping and historical records while an inventory map from 2017, compiled for the study area (21 km2), is based on LiDAR data acquired in December 2013. A comparison of three landslide inventory maps was performed with three tests based on landslide statistics, frequency-area distribution, geographical discrepancy of landslides and landslide density maps. The results show significant differences in the number of identified landslides as well as in the size and distribution of landslides. A comparison of inventories also showed the unreliability of the existing historical inventories and usefulness of LiDAR data for preparation of complete landslide inventory maps. LiDAR-based inventory for the Podsljeme area could be a valuable tool for a wide range of users i.e., decision-makers, land developers and environmental and civil defense agencies. It is also necessary for landslide susceptibility and hazard mapping, which is a prerequisite for landslide risk reduction.Klizišta su vrlo česta pojava u brežuljkastome dijelu grada Zagreba zbog geomorfoloških, geoloških i klimatskih preduvjeta. Na području podsljemenske zone grada Zagreba postoje dva povijesna inventara klizišta, prvi iz 1979. godine i drugi iz 2007. godine, a oba su izrađena na temelju geomorfološkoga kartiranja i arhivskih podataka. Na temelju podataka laserskoga skeniranja (LiDAR) iz zraka provedenoga tijekom prosinca 2013. godine izrađen je inventar klizišta za područje površine 21 km2, smješteno u zapadnome dijelu podsljemenske zone. Usporedba triju inventara klizišta provedena je pomoću triju analiza koje se temelje na raspodjeli učestalosti klizišta, razlici u geografskome položaju pojedinih klizišta u inventaru klizišta te kartama gustoće klizišta. Rezultati analize triju inventara klizišta upućuju na znatnu razliku u broju klizišta u pojedinim inventarima, veličinu klizišta i prostornu raspodjelu, na temelju čega se može zaključiti kako su povijesni inventari klizišta nepouzdani te kako LiDAR podaci omogućavaju izradu potpunoga inventara klizišta. Inventar klizišta za cijelo područje podsljemenske zone izrađen na temelju digitalnoga modela terena visoke rezolucije dobivenoga laserskim skeniranjem iz zraka (LiDAR DMT) imao bi široku primjenu prilikom izdavanja građevinskih i lokacijskih dozvola, prostornih planova te u sklopu zaštite okoliša i civilne zaštite, a također je nuždan za izradu prognoznih karata, karte podložnosti, hazarda i rizika od klizanja

Mineralogical and Physical Properies of Typical Soils from Zagreb Podsljeme Area

Zbog specifične geomorfologije, složene geološke građe, te uslijed nagle i često neodgovarajuće izgradnje građevina, na području podsljemenske zone grada Zagreba prisutan je problem vezan uz stabilnost padina.Brojna klizišta predstavljaju prijetnju lokalnom stanovništvu i imovini. Na inženjerskogeološke uvjete u podsljemenskoj zoni najveći utjecaj imaju sitnozrnasta tla pleistocenske i gornjomiocenske starosti koja zauzimaju oko 70 % ukupne površine ovog područja. U okviru projekta „Detaljna inženjerskogeološka karta Podsljemenske urbanizirane zone M 1:5000 – FAZA I“ (skraćeno DIGK – FAZA I) provedena su istraživanja s ciljem utvrđivanja fizičko - mehaničkih svojstava tala u površinskom dijelu cijele podsljemenske zone do maksimalne dubine od 5 m, kao i dubljih profila tala na odabranim lokacijama. Istraživanja su obuhvaćala geomehanička ispitivanja i mineraloške analize. Analizom svih rezultata ispitivanjadobiven je uvidu vrste tala i njihovu relativnu zastupljenost u podsljemenskoj zoni s naglaskom na sitnozrnaste vrste tla te njihove sličnosti i razlike u odnosu na fizička svojstva, litostratigrafsku pripadnost ovisno o pripadnost i mineralni sastav.Due to the specific geomorphology, complex geological structures and as a consequence of quick and inadequate construction of buildings, there is a problem with the stability of the slopes in the Podsljeme area of Zagreb. The numerous landslides pose a threat to the local population and their property. The greatest influence on the engineering geological conditions in Podsljeme area have fine – grained soils which occupy about 70 % of total area. Within the framework of the project "Detailed engineering geological map of Zagreb Podsljeme area M 1: 5000 - PHASE I" (abbreviated DIGK – PHASE I), research was carried out to determine the engineering geological properties of soil in the surface area of the entire sub zone up to a maximum depth of 5 m as well as deeper profiles on selected locations. The investigations included geomechanical and mineralogical analyses. Based on the obtained data and their analyzes the authors represent a clear picture of the engineering soils in the Podsljeme area and their similarity and differences in relation to the physical and mechanical properties, the lithostratigraphic affiliation and the mineralogical composition

KINEMATIČKI MODEL SPOROGA KLIZIŠTA KOSTANJEK (GRAD ZAGREB, HRVATSKA)

The interpretation of landslide kinematics provides important information for those responsible for the management of landslide risk. This paper presents an interpretation of the kinematics of the slow-moving Kostanjek landslide, located in the urbanized area of the city of Zagreb, Croatia. The sliding material (very weak to weak marls, often covered with clayey topsoil) exhibits plastic, rather than rigid behavior. Due to this reason, and low landslide velocities, landslide features, such as main scarps or lateral flanks, are barely noticeable or do not exist in most of the landslide area. The data used for the kinematic interpretation were obtained from 15 GNSS sensors, for the period of 2013-2019. The monitoring data revealed a different spatial and temporal distribution of landslide velocities, resulting as a consequence of geomorphological conditions and forces that govern the landslide movements. Temporally, eight periods of faster movements and seven periods of slower movements were determined. Spatially, velocities measured in the central part of the landslide were higher than on its boundaries. The interpretation of the surface (horizontal and vertical) displacements and the direction of movement reveal a new insight into the engineering geological model and provide important information for the management of the Kostanjek landslide risk.Interpretacija kinematičkoga modela klizišta važan je podatak pri procjeni ugroženosti za stanovnike, građevine i infrastrukturu na području klizišta. Ovaj članak opisuje interpretaciju kinematičkoga modela sporoga klizišta Kostanjek, koje se nalazi u gradu Zagrebu. Materijali u klizanju (vrlo slabi do slabi lapori, često prekriveni glinovitim pokrivačem) uglavnom pokazuju plastično ponašanje. Zbog toga, a i zbog male brzine klizišta, dijelovi klizišta kao što su glavna pukotina ili bokovi klizišta izostaju ili nisu jasno izraženi na površini terena. Podatci korišteni za interpretaciju kinematičkoga modela prikupljeni su s 15 GNSS uređaja, u razdoblju između 2013. i 2019. godine. Podatci praćenja upućuju na različitu prostornu i vremensku raspodjelu brzina, koja je posljedica geomorfoloških uvjeta te sila koje uzrokuju gibanje klizišta. Vremenski je moguće raspoznati osam razdoblja bržega gibanja i sedam razdoblja sporijega gibanja, dok su prostorno veće brzine izmjerene u središnjemu dijelu klizišta nego na njegovim rubovima. Rezultati interpretacije horizontalnih i vertikalnih pomaka te smjerova gibanja upućuju na novi inženjerskogeološki model klizišta te pružaju važne podatke za prostorno planiranje i civilnu zaštitu