Determining the characteristics of karst aquifer on southwestern Žumberak area using quantitative tracing in various hydrological conditions : doctoral thesis

Vodonosnici krških izvora Jaža i Obrv na jugozapadnom Žumberku do sada nisu bili detaljno istraživani. Cilj istraživanja je bio definirati utjecaj različitih hidroloških uvjeta na parametre tečenja i transporta (srednja efektivna brzina i disperzija) kroz krške kanale na primjeru vodonosnika Jaže i Obrva. Dobivene spoznaje će ujedno pridonijeti boljem poznavanju građe i funkcioniranja samih vodonosnika. Osnovna metoda su bila kvantitativna trasiranja koja su ponavljana u različitim hidrološkim uvjetima i njihovi rezultati analizirani analitičkim modelima (metoda momenata, CDE, SFDM, MDM, 2RNE). Dodatno je analizirana dinamika izvora i ponora, prirodni traseri i hidrokemija izvorske vode. Izveden je niz simultanih trasiranja ponora na kontaktu „Vivodinskog fliša“ i vapnenačkih breča. Traser je detektiran isključivo na izvoru Jaža. Dodatno je izvršeno trasiranje jame u naslagama dolomita. U tom slučaju traser je zabilježen isključivo na izvoru Obrv s vrlo neuobičajenom krivuljom koncentracije trasera. Ustanovljeno je da su slivovi izvora Jaže i Obrv odvojeni. Napajanje Jaže dolazi s područja „Vivodinskog fliša“ i dijelom iz gornjokrednih vapnenačkih breča u zaleđu izvora. Obrv se napaja iz gornjotrijaskih „glavnih“ dolomita i gornjokrednih vapnenačkih breča. Naslage vapnenačkih breča, prethodno definirane kao osrednje propusne, kategorizirane su kao vrlo dobro propusne naslage. Vodonosnici Jaže i Obrva se sastoje najvećim dijelom od dobro propusnih pukotina i krških kanala. Volumen sitnih pukotina i matriksa je kod njih netipično mali. Srednja brzina trasera raste povećanjem količine vode u sustavu. Disperzija je najniža u uvjetima srednjih voda, a najveća u uvjetima visokih voda. Nailazak vodnih valova može povećati, ali i smanjiti disperziju ovisno o vremenu preklapanja.Karst aquifers from springs Jaža and Obrv haven`t been thoroughly investigated until now. Purpose of this investigation was defining influence of various hydrological conditions on flow and transport parameters (mean flow velocity and dispersion) in karst conduits. The resulting findings will also contribute to a better understanding of the structure and functioning of the aquifers themselves. Basic method was repeated quantitative tracing in various hydrological conditions. Results were analyzed by analytical models (method of moments, CDE, SFDM, MDM, 2RNE). Additionally, flow dynamic with natural tracers and hydro chemical analysis were conducted. A series of tracing tests on ponors on contact between “Vivodina flisch” and limestone breccias were conducted. Tracer was detected only in Jaža spring. Another tracing test done in the dolomites resulted in tracer appearing only on Obrv spring with very unusual tracer breakthrough curve. Recharge of Jaža and Obrv springs are separated. Jaža spring recharges from “Vivodina flisch” and Upper Cretaceous limestone breccias. Obrv spring recharges from Upper Triassic “main” dolomites and Upper Cretaceous limestone breccias. Limestone breccias were reclassified from moderately permeable to very well permeable. Jaze and Obrv aquifers consist mostly of well-permeable fractures and conduits. Volume of tiny cracks and matrix is untypically small. Mean tracer velocity increases with increasing water volume in the system. Dispersion is the lowest during mean water conditions, and the largest during high water conditions. Storm events may increase, but also reduce dispersion depending on the time of overlap

Determining the characteristics of karst aquifer on southwestern Žumberak area using quantitative tracing in various hydrological conditions : doctoral thesis

Vodonosnici krških izvora Jaža i Obrv na jugozapadnom Žumberku do sada nisu bili detaljno istraživani. Cilj istraživanja je bio definirati utjecaj različitih hidroloških uvjeta na parametre tečenja i transporta (srednja efektivna brzina i disperzija) kroz krške kanale na primjeru vodonosnika Jaže i Obrva. Dobivene spoznaje će ujedno pridonijeti boljem poznavanju građe i funkcioniranja samih vodonosnika. Osnovna metoda su bila kvantitativna trasiranja koja su ponavljana u različitim hidrološkim uvjetima i njihovi rezultati analizirani analitičkim modelima (metoda momenata, CDE, SFDM, MDM, 2RNE). Dodatno je analizirana dinamika izvora i ponora, prirodni traseri i hidrokemija izvorske vode. Izveden je niz simultanih trasiranja ponora na kontaktu „Vivodinskog fliša“ i vapnenačkih breča. Traser je detektiran isključivo na izvoru Jaža. Dodatno je izvršeno trasiranje jame u naslagama dolomita. U tom slučaju traser je zabilježen isključivo na izvoru Obrv s vrlo neuobičajenom krivuljom koncentracije trasera. Ustanovljeno je da su slivovi izvora Jaže i Obrv odvojeni. Napajanje Jaže dolazi s područja „Vivodinskog fliša“ i dijelom iz gornjokrednih vapnenačkih breča u zaleđu izvora. Obrv se napaja iz gornjotrijaskih „glavnih“ dolomita i gornjokrednih vapnenačkih breča. Naslage vapnenačkih breča, prethodno definirane kao osrednje propusne, kategorizirane su kao vrlo dobro propusne naslage. Vodonosnici Jaže i Obrva se sastoje najvećim dijelom od dobro propusnih pukotina i krških kanala. Volumen sitnih pukotina i matriksa je kod njih netipično mali. Srednja brzina trasera raste povećanjem količine vode u sustavu. Disperzija je najniža u uvjetima srednjih voda, a najveća u uvjetima visokih voda. Nailazak vodnih valova može povećati, ali i smanjiti disperziju ovisno o vremenu preklapanja.Karst aquifers from springs Jaža and Obrv haven`t been thoroughly investigated until now. Purpose of this investigation was defining influence of various hydrological conditions on flow and transport parameters (mean flow velocity and dispersion) in karst conduits. The resulting findings will also contribute to a better understanding of the structure and functioning of the aquifers themselves. Basic method was repeated quantitative tracing in various hydrological conditions. Results were analyzed by analytical models (method of moments, CDE, SFDM, MDM, 2RNE). Additionally, flow dynamic with natural tracers and hydro chemical analysis were conducted. A series of tracing tests on ponors on contact between “Vivodina flisch” and limestone breccias were conducted. Tracer was detected only in Jaža spring. Another tracing test done in the dolomites resulted in tracer appearing only on Obrv spring with very unusual tracer breakthrough curve. Recharge of Jaža and Obrv springs are separated. Jaža spring recharges from “Vivodina flisch” and Upper Cretaceous limestone breccias. Obrv spring recharges from Upper Triassic “main” dolomites and Upper Cretaceous limestone breccias. Limestone breccias were reclassified from moderately permeable to very well permeable. Jaze and Obrv aquifers consist mostly of well-permeable fractures and conduits. Volume of tiny cracks and matrix is untypically small. Mean tracer velocity increases with increasing water volume in the system. Dispersion is the lowest during mean water conditions, and the largest during high water conditions. Storm events may increase, but also reduce dispersion depending on the time of overlap

Determining the characteristics of karst aquifer on southwestern Žumberak area using quantitative tracing in various hydrological conditions : doctoral thesis

Vodonosnici krških izvora Jaža i Obrv na jugozapadnom Žumberku do sada nisu bili detaljno istraživani. Cilj istraživanja je bio definirati utjecaj različitih hidroloških uvjeta na parametre tečenja i transporta (srednja efektivna brzina i disperzija) kroz krške kanale na primjeru vodonosnika Jaže i Obrva. Dobivene spoznaje će ujedno pridonijeti boljem poznavanju građe i funkcioniranja samih vodonosnika. Osnovna metoda su bila kvantitativna trasiranja koja su ponavljana u različitim hidrološkim uvjetima i njihovi rezultati analizirani analitičkim modelima (metoda momenata, CDE, SFDM, MDM, 2RNE). Dodatno je analizirana dinamika izvora i ponora, prirodni traseri i hidrokemija izvorske vode. Izveden je niz simultanih trasiranja ponora na kontaktu „Vivodinskog fliša“ i vapnenačkih breča. Traser je detektiran isključivo na izvoru Jaža. Dodatno je izvršeno trasiranje jame u naslagama dolomita. U tom slučaju traser je zabilježen isključivo na izvoru Obrv s vrlo neuobičajenom krivuljom koncentracije trasera. Ustanovljeno je da su slivovi izvora Jaže i Obrv odvojeni. Napajanje Jaže dolazi s područja „Vivodinskog fliša“ i dijelom iz gornjokrednih vapnenačkih breča u zaleđu izvora. Obrv se napaja iz gornjotrijaskih „glavnih“ dolomita i gornjokrednih vapnenačkih breča. Naslage vapnenačkih breča, prethodno definirane kao osrednje propusne, kategorizirane su kao vrlo dobro propusne naslage. Vodonosnici Jaže i Obrva se sastoje najvećim dijelom od dobro propusnih pukotina i krških kanala. Volumen sitnih pukotina i matriksa je kod njih netipično mali. Srednja brzina trasera raste povećanjem količine vode u sustavu. Disperzija je najniža u uvjetima srednjih voda, a najveća u uvjetima visokih voda. Nailazak vodnih valova može povećati, ali i smanjiti disperziju ovisno o vremenu preklapanja.Karst aquifers from springs Jaža and Obrv haven`t been thoroughly investigated until now. Purpose of this investigation was defining influence of various hydrological conditions on flow and transport parameters (mean flow velocity and dispersion) in karst conduits. The resulting findings will also contribute to a better understanding of the structure and functioning of the aquifers themselves. Basic method was repeated quantitative tracing in various hydrological conditions. Results were analyzed by analytical models (method of moments, CDE, SFDM, MDM, 2RNE). Additionally, flow dynamic with natural tracers and hydro chemical analysis were conducted. A series of tracing tests on ponors on contact between “Vivodina flisch” and limestone breccias were conducted. Tracer was detected only in Jaža spring. Another tracing test done in the dolomites resulted in tracer appearing only on Obrv spring with very unusual tracer breakthrough curve. Recharge of Jaža and Obrv springs are separated. Jaža spring recharges from “Vivodina flisch” and Upper Cretaceous limestone breccias. Obrv spring recharges from Upper Triassic “main” dolomites and Upper Cretaceous limestone breccias. Limestone breccias were reclassified from moderately permeable to very well permeable. Jaze and Obrv aquifers consist mostly of well-permeable fractures and conduits. Volume of tiny cracks and matrix is untypically small. Mean tracer velocity increases with increasing water volume in the system. Dispersion is the lowest during mean water conditions, and the largest during high water conditions. Storm events may increase, but also reduce dispersion depending on the time of overlap

Use of a LiDAR-derived landslide inventory map in assessing Influencing factors for landslide susceptibility of geological units in the Petrinja area (Croatia)

A landslide inventory was created for an area of 22.6 km2 near Petrinja city in northern Croatia, based on the high-resolution LiDAR data complemented by orthophoto maps. A total of 216 landslides were identified, covering 2.91 % of that area. Landslide polygons were overlain on geological units based on the Basic map of SFRY at a scale of 1:100,000 that is the largest scale geological map available for the whole of Croatia. The relationship between landslides and geological units was expressed as a landslide index. Three geological units displayed increased landslide susceptibility. A Pliocene unit clearly had the largest susceptibility, followed by a Palaeocene-Eocene unit, and finally a Badenian unit. Landslide density was analyzed within these geological units to identify influencing factors for landslide initiation. Each geological unit revealed different influencing factors. The Pliocene unit is mostly influenced by bedding plane orientation and local relief. Heterogeneousness lithology is the dominant factor in the Paleocene-Eocene unit, while the Badenian unit demonstrated the least certain interpretation as there are multiple factors involved. The forest road is presumed to be crucial, followed by spring occurrences and proximity to the tectonic boundary. The basic geological map of SFRY proved to be a viable source of geological information for the creation of landslide susceptibility maps at a scale of up to 1:100,000, but with limitations in the case of lithologically heterogeneous geological units. Larger scale maps require more detailed research as landslide susceptibility factors vary in each geological unit

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

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

Geological Model of Pićan Area, Istria

During geological mapping of Istria (Croatia) numerous carbonate beds (megabeds) were recorded within the informal lithostratigraphic unit Istrian flysch. Istrian flysch deposits are mostly characterized by typical alter-nations of hemipelagical marl and gravity-flow deposits (BERGANT et al., 2003). The monotonous succession of marl and mixed carbonate-siliciclastic sandstone is intercalated with several relatively thick carbonate beds - megabeds, composed of breccia, conglomerate, bioclastic arenite/siltite and marl. The thickness of these megabeds varies between 0.5–5 m, rarely over 10 m. The megabeds are interpreted as complex sequences of rockfall, debrite and turbidite deposits, characteristic for the lower part of the basin fill (BERGANT et al., 2003). In eastern Istria, near the town of Pićan, an unusual carbonate layer is mapped, named “Pićan bed“, whose genesis cannot be explained by the depositional mechanisms of turbidite currents or debris flows, characteristic for the Istrian Flysch deposits. For this purpose, a more detailed field investigation was performed and a sedimentary log (Pić-I) was recorded within a tectonically undisturbed succession of Paleogene deposits. At the base of the succession an informal lithostratigraphic unit “Foraminiferal limestone” gradually transitions into “Marls with Crabs” and further into “Globigerina marls” informal lithostratigraphic units. The interval of massive “Globigeri-na marls” is approx. 100 m thick and transitions into the Istrian flysch lithostratigraphic unit, here represented with this unusual “Pićan bed”. Flysch deposits are composed of calcarenite beds, marl, sandstone, and, of course, megabeds are well documented in the surrounding area. The sedimen-tary log was used to complement the new lithostratigraphic map of the area (PETRINJAK et al., 2018).The geological model of the Pićan area was built based primarily on the lithostratigraphic map and geological cross-sections, and the Digital Surface Model (DSM) of the area. The data were modelled using Midland Valley Move geological modelling software. The new lithostratigraphic map together with other available data, such as Digital Orthophoto Images of the area were used to construct a series of geological cross-sections needed for the model, while an Unmanned Aerial Vehicle (UAV) was used to record the DSM of the area.Finally, the geological model of the Pićan area displays, faithfully as possible, the spatial distribution of the “Pićan bed“ and the interesting geological setting of the Pićan area, Istria

Hydrogeological Assessment and Modified Conceptual Model of a Dinaric Karst Island Aquifer

Vis Island is situated in southern Croatia. The island is mostly composed of karstified carbonate rocks and belongs to the Dinaric karst region, which is a locus typicus of karst landforms. Located far from the mainland, Vis island has maintained a successful water supply from its own karst aquifer for decades. Hydrogeological research has been undertaken to protect this excellent karst aquifer by establishing sanitary protection zones and to explore the possibility of increasing the pumping yield. New groundwater velocity data obtained via a tracer test were in accordance with the rock mass hydraulic conductivity calculated from previous pumping tests. The hydrochemical interpretation indicated several different phenomena, from carbonate and sulfate rock dissolution to seawater mixing with groundwater. A conceptual model of the island’s aquifer was improved, and two main catchments were delineated according to tracer test results, and connected with the geological setting, hydrochemical data, and new climatological insights. Such an approach is applicable for similar karst aquifers, in which topographic and hydrogeological divides usually do not coincide

Hydrogeological Assessment and Modified Conceptual Model of a Dinaric Karst Island Aquifer

Vis Island is situated in southern Croatia. The island is mostly composed of karstified carbonate rocks and belongs to the Dinaric karst region, which is a locus typicus of karst landforms. Located far from the mainland, Vis island has maintained a successful water supply from its own karst aquifer for decades. Hydrogeological research has been undertaken to protect this excellent karst aquifer by establishing sanitary protection zones and to explore the possibility of increasing the pumping yield. New groundwater velocity data obtained via a tracer test were in accordance with the rock mass hydraulic conductivity calculated from previous pumping tests. The hydrochemical interpretation indicated several different phenomena, from carbonate and sulfate rock dissolution to seawater mixing with groundwater. A conceptual model of the island’s aquifer was improved, and two main catchments were delineated according to tracer test results, and connected with the geological setting, hydrochemical data, and new climatological insights. Such an approach is applicable for similar karst aquifers, in which topographic and hydrogeological divides usually do not coincide

SALTECTA – salt diapirs and active tectonics in the Central Adriatic

Srednji Jadran je predgorje dvaju orogenih sustava – Dinarida na sjeveroistoku i Apenina na jugozapadu. Osim velike debljine naslaga, to područje obilježava i specifična predgorska tektonika te brojne solne strukture. Te halokinetske strukture različito su prikazivane na objavljenim preglednim kartama i ilustracijama geoloških profila, a tek sporadično na interpretiranim seizmičkim profilima. Solni dijapiri čine impozantne potpovršinske strukture koje mjestimice izbijaju na površinu i tako utječu na morfologiju (batimetriju) tog područja. Solne strukture srednjeg Jadrana su znanstveno nedovoljno istražene, a nije istraživana niti uzročno-posljedična veza halokinetike i umjerene seizmičke aktivnosti koja obilježava to područje. Pretpostavlja se da je izdizanje soli vezano uz neotektonsku reaktivaciju mezozojskih rasjeda, od kojih su neki vjerojatno i danas aktivni. Projektom se namjeravaju interpretirati najnoviji 2D seizmički profili odobreni od strane Agencije za ugljikovodike (AZU), reinterpretirati gravimetrijski podatci, definirati glavni rasjedi te 3D modelirati geometrija odabranih solnih struktura. Strukturno-tektonski sklop (re)definirat će se na pučinskim otocima srednjeg Jadrana (slika 1). Uspoređivanjem prostornog rasporeda epicentara i hipocentara zabilježenih potresa s interpretiranim geološkim strukturama, pokušat će se razjasniti povezanost aktivne tektonike sa solnim strukturama. Istraživanjem i datiranjem najmlađih (kvartarnih) naslaga pokušat će se definirati neotektonska aktivnost solnih dijapira. Istraživanjem odabranih markantnih (sub)recentnih erozijskih oblika nastojat će se procijeniti prošla i buduća seizmotektonska aktivnost i seizmogeohazardi