Spatial distribution and geometric characteristics of landslides with special reference to geological units in the area of Slavonski Brod, Croatia

A preliminary analysis of landslide spatial distribution and their geometric characteristics is presented for the area of Slavonski Brod, located in the northeastern part of Croatia and belonging to the Pannonian Basin System. A landslide inventory for the study area of 55.1 km2 is accomplished for the first time, based on the visual interpretation of a high resolution LiDAR digital terrain model. In total, 854 landslide polygons are delineated, corresponding to an average density of 15.5 landslides per square kilometre. The average landslide area is 839 m2, and most of the landslides can be classified as small landslides (76 %). The spatial relationship between landslides and geological units is analysed and expressed as a landslide index. The Late Pannonian sands with silts and gravel interlayers and Pliocene clay, sands, gravels, and coal are determined as the units that are most susceptible to landslide processes. The majority of landslides (85 %) are concentrated within these two units, for which a detailed analysis is performed, determining the morphometric parameters (slope and relief) and drainage network. The parameters’ classes that create favourable preconditions to slope instabilities are defined, based on the landslide density within individual classes. Besides, the geometric characteristics of landslides (size and shape) within these two units are compared. The results serve as the basis for further investigations. They help to foresee the area of future landslides through landslide susceptibility maps, and offer a better understanding of the influence of fluvial-denudation and slope processes on recent landscape evolution and form

Preliminary analysis of a LiDAR-based landslide inventory in the area of Samobor, Croatia

The paper presents an analysis of the LiDAR-based landslide inventory for the area near Samobor, in northwestern Croatia with two main objectives: i) to define the geological units (obtained from Basic Geological Map of Croatia) most susceptible to landslides, and ii) to analyse the limitations of the Basic Geological Map and its applicability in landslide susceptibility map design. Within the study area of 63.8 km2, 874 landslide polygons were manually outlined, covering an area of 2.15 km2. The landslide outline confidence level, landslide index and the relief energy map were used to analyse the landslide susceptibility of a particular geological unit. By that, units in the same state of stress, i.e., in the same relief energy group were compared. This preliminary analysis has shown that the geological units Pl,Q, M3 1,2, and 1M3 1 are the most susceptible to landslides and that older geological units, Pc and K1,2, are also prone to landslides. Still, landslides within those older units can be considered as old and inactive. As for the limitations of the Basic Geological Map of Croatia, three things emerged, namely scale, the geological unit defining approach, and the neglect of regolith. Despite the limitations presented, the usability of the Basic Geological Map of Croatia in the development of small-scale landslide susceptibility maps is emphasized. However, instructions that should attribute engineering geological features to the geological units outlined in the Basic Geological Map should be prepared in the near future

Development of rockfall threat assessment system along railways in carbonate rocks in the Republic of Croatia : doctoral thesis

Odroni su kao geološki hazard posebno značajni uz ceste i željezničke pruge. Kako bi se njihovu upravljanju pristupilo proaktivno, nužna je standardizirana metoda kojom je moguće međusobno usporediti kosine i na logičan način izdvojiti one koje predstavljaju prioritet za sanaciju. Za njezino provođenje potrebno je odabrati relevantne parametre i način njihovog vrednovanja, a oni se u sklopu doktorskog rada temelje na nekoliko verzija postojećeg Rockfall Hazard Rating System-a. Pri tome je glavni cilj istraživanja usmjeren na njegovu prilagodbu kosinama izvedenim uz željezničku prugu u karbonatnim stijenama Hrvatske. Sustav se temelji na eksponencijalnom bodovanju inženjerskogeoloških i klimatskih značajki koje utječu na mogućnost pojave odrona, te geometrijskih značajki kosine koje utječu na mogućnost da odlomljeni materijal dosegne prugu. Podaci o svim značajkama prikupljeni su jednostavnim opažanjima tijekom inženjerskogeološke prospekcije. Analizirano je 366 segmenata kosina koje su prostorno smještene u području Krških Dinarida i generalno obuhvaćaju područje od Rijeke, preko Gorskog Kotara i Like, do Splita. Prema odabiru parametara i načinu njihovog vrednovanja definirano je 16 bodovnih modela. Za svaki od njih provedena je klasifikacija kosina koja se temelji na kombinaciji klasa prema ukupnom broju bodova i klasa prema odnosu bodova parametara uzroka i posljedice. Konačni rezultat predstavlja jedna od četiri definirane klase kosine prema ugroženosti od odrona. Najprikladniji bodovni model prema uvjetima na istraživanom području odabran je na temelju rezultata verifikacije provedene s tri seta podataka. Oni uključuju preliminarnu procjenu, stabilnost kosina definiranu prema Regionalnim jedinicama održavanja i tragove odrona. Za odabrani model provedene su statističke analize linearne i logističke regresije. One su omogućile određivanje statistički značajnih parametara za svaki korak razrađene metodologije procjene ugroženosti od odrona, kao i optimizaciju bodovnog modela. U sklopu doktorskog rada razrađeni su elementi za razvoj sustava ugroženosti od odrona koji predstavlja prvi korak u cjelovitom upravljanju hazardima i rizicima od odrona.Rockfalls, as a type of geological hazard, are especially important along the roads and railways. In terms of proactive management approach, it is necessary to standardize a method which allows comparison between slopes and logical separation of those that represent a priority for remediation. For its implementation, selection of the relevant parameters and the manl'ler of their rating is required. In this doctoral dissertation they are based on several versions of existing Rockfall Hazard Rating System. However, the main aim of the research is focused on system modification to the slopes along railways in carbonate rocks of Croatia. The system is based on an exponential scoring of engineering geological (EG) and climatic characteristics that affect the rockfall potential, and geometric features of slopes that affect the possibility that the material reaches the railway. Data about all these features is collected within a simple observation during EG prospecting. A total of 366 segments of slopes have been analysed. They are spatially located in the Karst Dinarides of Croatia, generally including the area from Rijeka, through the Gorski Kotar area and Lika, to Split. According to the selection parameters and their ratings, 16 scoring models are defined. For each of them, the slope classification is conducted, based on the combination of classes of the total scores of all parameters and classes of the relation between the scores for causes and consequences. The final result represents one of the four defined slope classes according to rockfall threat. The most appropriate scoring model was chosen based on the results of the verification carried out with three sets of parameters. They include information of the preliminary rating, slope stability defined by the Regional Maintenance Administration and traces of rockfall. For the selected model statistical analysis of linear and logistic regression are performed. They enabled the determination of statistically significant parameters for assessing the rockfall threat, as well as the optimization of the scoring model. The main elements for the development of rockfall threat system are elaborated. Those represent the first step in the comprehensive rockfall hazard and risk management

Development of rockfall threat assessment system along railways in carbonate rocks in the Republic of Croatia : doctoral thesis

Odroni su kao geološki hazard posebno značajni uz ceste i željezničke pruge. Kako bi se njihovu upravljanju pristupilo proaktivno, nužna je standardizirana metoda kojom je moguće međusobno usporediti kosine i na logičan način izdvojiti one koje predstavljaju prioritet za sanaciju. Za njezino provođenje potrebno je odabrati relevantne parametre i način njihovog vrednovanja, a oni se u sklopu doktorskog rada temelje na nekoliko verzija postojećeg Rockfall Hazard Rating System-a. Pri tome je glavni cilj istraživanja usmjeren na njegovu prilagodbu kosinama izvedenim uz željezničku prugu u karbonatnim stijenama Hrvatske. Sustav se temelji na eksponencijalnom bodovanju inženjerskogeoloških i klimatskih značajki koje utječu na mogućnost pojave odrona, te geometrijskih značajki kosine koje utječu na mogućnost da odlomljeni materijal dosegne prugu. Podaci o svim značajkama prikupljeni su jednostavnim opažanjima tijekom inženjerskogeološke prospekcije. Analizirano je 366 segmenata kosina koje su prostorno smještene u području Krških Dinarida i generalno obuhvaćaju područje od Rijeke, preko Gorskog Kotara i Like, do Splita. Prema odabiru parametara i načinu njihovog vrednovanja definirano je 16 bodovnih modela. Za svaki od njih provedena je klasifikacija kosina koja se temelji na kombinaciji klasa prema ukupnom broju bodova i klasa prema odnosu bodova parametara uzroka i posljedice. Konačni rezultat predstavlja jedna od četiri definirane klase kosine prema ugroženosti od odrona. Najprikladniji bodovni model prema uvjetima na istraživanom području odabran je na temelju rezultata verifikacije provedene s tri seta podataka. Oni uključuju preliminarnu procjenu, stabilnost kosina definiranu prema Regionalnim jedinicama održavanja i tragove odrona. Za odabrani model provedene su statističke analize linearne i logističke regresije. One su omogućile određivanje statistički značajnih parametara za svaki korak razrađene metodologije procjene ugroženosti od odrona, kao i optimizaciju bodovnog modela. U sklopu doktorskog rada razrađeni su elementi za razvoj sustava ugroženosti od odrona koji predstavlja prvi korak u cjelovitom upravljanju hazardima i rizicima od odrona.Rockfalls, as a type of geological hazard, are especially important along the roads and railways. In terms of proactive management approach, it is necessary to standardize a method which allows comparison between slopes and logical separation of those that represent a priority for remediation. For its implementation, selection of the relevant parameters and the manl'ler of their rating is required. In this doctoral dissertation they are based on several versions of existing Rockfall Hazard Rating System. However, the main aim of the research is focused on system modification to the slopes along railways in carbonate rocks of Croatia. The system is based on an exponential scoring of engineering geological (EG) and climatic characteristics that affect the rockfall potential, and geometric features of slopes that affect the possibility that the material reaches the railway. Data about all these features is collected within a simple observation during EG prospecting. A total of 366 segments of slopes have been analysed. They are spatially located in the Karst Dinarides of Croatia, generally including the area from Rijeka, through the Gorski Kotar area and Lika, to Split. According to the selection parameters and their ratings, 16 scoring models are defined. For each of them, the slope classification is conducted, based on the combination of classes of the total scores of all parameters and classes of the relation between the scores for causes and consequences. The final result represents one of the four defined slope classes according to rockfall threat. The most appropriate scoring model was chosen based on the results of the verification carried out with three sets of parameters. They include information of the preliminary rating, slope stability defined by the Regional Maintenance Administration and traces of rockfall. For the selected model statistical analysis of linear and logistic regression are performed. They enabled the determination of statistically significant parameters for assessing the rockfall threat, as well as the optimization of the scoring model. The main elements for the development of rockfall threat system are elaborated. Those represent the first step in the comprehensive rockfall hazard and risk management

Development of rockfall threat assessment system along railways in carbonate rocks in the Republic of Croatia : doctoral thesis

Odroni su kao geološki hazard posebno značajni uz ceste i željezničke pruge. Kako bi se njihovu upravljanju pristupilo proaktivno, nužna je standardizirana metoda kojom je moguće međusobno usporediti kosine i na logičan način izdvojiti one koje predstavljaju prioritet za sanaciju. Za njezino provođenje potrebno je odabrati relevantne parametre i način njihovog vrednovanja, a oni se u sklopu doktorskog rada temelje na nekoliko verzija postojećeg Rockfall Hazard Rating System-a. Pri tome je glavni cilj istraživanja usmjeren na njegovu prilagodbu kosinama izvedenim uz željezničku prugu u karbonatnim stijenama Hrvatske. Sustav se temelji na eksponencijalnom bodovanju inženjerskogeoloških i klimatskih značajki koje utječu na mogućnost pojave odrona, te geometrijskih značajki kosine koje utječu na mogućnost da odlomljeni materijal dosegne prugu. Podaci o svim značajkama prikupljeni su jednostavnim opažanjima tijekom inženjerskogeološke prospekcije. Analizirano je 366 segmenata kosina koje su prostorno smještene u području Krških Dinarida i generalno obuhvaćaju područje od Rijeke, preko Gorskog Kotara i Like, do Splita. Prema odabiru parametara i načinu njihovog vrednovanja definirano je 16 bodovnih modela. Za svaki od njih provedena je klasifikacija kosina koja se temelji na kombinaciji klasa prema ukupnom broju bodova i klasa prema odnosu bodova parametara uzroka i posljedice. Konačni rezultat predstavlja jedna od četiri definirane klase kosine prema ugroženosti od odrona. Najprikladniji bodovni model prema uvjetima na istraživanom području odabran je na temelju rezultata verifikacije provedene s tri seta podataka. Oni uključuju preliminarnu procjenu, stabilnost kosina definiranu prema Regionalnim jedinicama održavanja i tragove odrona. Za odabrani model provedene su statističke analize linearne i logističke regresije. One su omogućile određivanje statistički značajnih parametara za svaki korak razrađene metodologije procjene ugroženosti od odrona, kao i optimizaciju bodovnog modela. U sklopu doktorskog rada razrađeni su elementi za razvoj sustava ugroženosti od odrona koji predstavlja prvi korak u cjelovitom upravljanju hazardima i rizicima od odrona.Rockfalls, as a type of geological hazard, are especially important along the roads and railways. In terms of proactive management approach, it is necessary to standardize a method which allows comparison between slopes and logical separation of those that represent a priority for remediation. For its implementation, selection of the relevant parameters and the manl'ler of their rating is required. In this doctoral dissertation they are based on several versions of existing Rockfall Hazard Rating System. However, the main aim of the research is focused on system modification to the slopes along railways in carbonate rocks of Croatia. The system is based on an exponential scoring of engineering geological (EG) and climatic characteristics that affect the rockfall potential, and geometric features of slopes that affect the possibility that the material reaches the railway. Data about all these features is collected within a simple observation during EG prospecting. A total of 366 segments of slopes have been analysed. They are spatially located in the Karst Dinarides of Croatia, generally including the area from Rijeka, through the Gorski Kotar area and Lika, to Split. According to the selection parameters and their ratings, 16 scoring models are defined. For each of them, the slope classification is conducted, based on the combination of classes of the total scores of all parameters and classes of the relation between the scores for causes and consequences. The final result represents one of the four defined slope classes according to rockfall threat. The most appropriate scoring model was chosen based on the results of the verification carried out with three sets of parameters. They include information of the preliminary rating, slope stability defined by the Regional Maintenance Administration and traces of rockfall. For the selected model statistical analysis of linear and logistic regression are performed. They enabled the determination of statistically significant parameters for assessing the rockfall threat, as well as the optimization of the scoring model. The main elements for the development of rockfall threat system are elaborated. Those represent the first step in the comprehensive rockfall hazard and risk management

Relation between relief and Badland spatial distribution in the Paleogene Pazin Basin, Croatia

ABSTRACTBadlands are specific landforms characterized by intense denudation processes. Their occurrence is mainly associated with clay-like materials and semi-arid and Mediterranean climates. This study presents the badland inventory for the Paleogene Pazin Basin located on the Istrian peninsula in Croatia. A total of 5,381 badland polygons, with a total area of 10.25 km2, were manually outlined, based on the visual interpretation of orthophotos at a scale of 1:5,000. The badlands in Istria are represented as small and isolated landforms and are exclusively associated with flysch and flysch-like materials, which cover a significant part of the study area (46%). The analysis of badland inventory shows that badlands are spatially not equally distributed but that their abundance is increasing from NW to SE part of the analyzed area. Additionally, the results of the spatial analysis indicate the positive relationship between badland occurrence and relative relief, which is presented via the relief-badland index

The preliminary inventory of coseismic ground failures related to December 2020 – January 2021 Petrinja earthquake series

The most recent major earthquake series struck near Petrinja (December 29th 2020 M 6.2), and triggered extensive ground failures in the wider area of Petrinja, Sisak and Glina. Coseismic ground failures including subsidence dolines, liquefaction and landslides have been documented over a large area by various experts and teams. These data are stored in the newly created inventory, which is openly presented in this paper. This inventory is administered and updated by the Croatian Geological Survey, and will be available online via a Web Map Service (WMS) (www.hgi-cgs.hr). The aim of the inventory is to not only provide data for the development of susceptibility maps and more detailed exploration for possible remediation measures, but also to define the priorities for immediate action. The earthquake triggered the rapid development of dropout dolines which endanger the local populations of the villages of Mečenčani and Borojevići. This is still an ongoing process in the vicinity of the houses and therefore in-situ exploration started immediately. Liquefaction related to alluvial sediments of the Sava, Kupa and Glina rivers occurred almost exclusively in loose and pure sands, and was accompanied by sand boils, subsidence and lateral spreading. Liquefaction also presents a greater hazard because settlement of houses and river embankments occurred. Lateral spreading caused failures of river flood embankments and natural river banks. According to the data known to date, the majority of the coseismic landslides were reactivated with minor displacements. Despite that, it has been recognised that houses at the edge, or in landslide colluvium suffered greater damage than other houses located outside the landslide impact zone