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This paper presents the preliminary results of analyses of landsliding processes derived from detailed LiDAR (Light Detection and Ranging) scans supported by field prospection on the southwestern slopes of Mt. Moslavačka gora, in the wider Kutina area. This area is known for frequent landslides, but dedicated regional landslide research has not been previously undertaken. High resolution LiDAR scanning and orthophoto imaging enabled the production of a reliable landslide inventory, but also enabled research on landslide properties and the morphology of the area. Field mapping and prospection, sampling and borehole coring assisted in the collection of information about the material characteristics and specific features of typical landslides. In the research area, which covers more than 71 km2, more than 1200 very small landslides were detected. The majority of landslides were discovered in just several geological units indicating their high susceptibility: Pleistocene silts and sands with clayey interlayers, followed by M2 silty sands and gravels, and M7 sands. Nearly half of the landslides are estimated to be of recent and younger age, while other landslides may be considered as being historical implying a "long tradition" of landslide events in the research area. Preliminary terrain surface roughness analysis also supported the conclusion that the inventory contains landslides of several historical generations which are still detectable. In addition to slides (1123), this research also discovered numerous earthflow processes (143), which are more frequent in the predominantly sandy units. The landslides in this area are largely located on the banks of the gullies and are directly related to the action of water. Regarding that situation and the engineering properties of the encountered geological units, four types of bank instabilities can be differentiated: slides on top of rock masses; slides in firm soil mixtures; landslides in sands; landslides in predominantly coherent soil complexes. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

The south-western part of Croatia, i.e. the area of central Istria, comprises the research area, (approximately 500 km²). It is characterized by a flysch complex with a great number of isolated relief landforms, termed badlands. The importance of badlands (areas with sparse or no vegetation) lies in the fact that sediment production from these areas is 8000 times higher than from areas with vegetation. Here, the badland inventory presents 5568 distinguishable badlands (polygons) with a total badland area of 10.7 km². Spatial analysis of the badland inventory showed that erosive channel flow at the steep slope foot is the most important factor in badland formation and development for the area of central Istria. [ABSTRACT FROM AUTHOR]

The experiences of developing engineering geological models in karst areas for designing and construction purposes prove the necessity of considering at least three basic submodels: sedimentological, structural-tectonic and the weathering one. The research presented here deals with very important and frequently neglected segments in each of the submodels. Therefore, particular attention should be directed to: better understanding of carbonate sediment deposition, determination of environment and diagenetic processes, study of the 3D anisotropy of discontinuity frequency, and differentiation of weathering zones. The given data and examples elaborate and justify such an approach, which enables a more realistic detailed engineering model, more reliable evaluations of the engineering geological/geotechnical parameters and real site conditions. [ABSTRACT FROM AUTHOR]

The complete geological characteristics of the wider area of the Pelješac peninsula are presented: lithostratigraphy, structural/tectonic geology and seismotectonics. The main emphasis is on the engineering geological characteristics of the clastic sediments in Mali Stun Bay, encountered during investigations for the building of the "Mainland- Pelješac" bridge project. The bridge has large proportions, as it is 2404 m in length and has 14 under-sea pylons. It required thorough and expensive in-situ and laboratory investigations which enabled the development of a detailed and reliable engineering model of the Quaternary clastic sediments at the exploration site. The results clearly indicate three different engineering units which are predominantly classified according to their obvious differences in consistency: Unit A- very soft and soft sediment; Unit B - soft to firm sediment and Unit C - firm sediment. Given the total sediment thickness, (locally over 100 m), the generally poor engineering properties, and the high seismic risk of the area, the substrate for the foundations is unfavourable. The units which are classified according to their engineering properties also tightly correspond to the depositional environments which represent a much wider area than just the exploration site. Therefore the authors presume the presence of units A, B and C in the wider area with similar geological settings to that in the proximity of the Zrmanja, Krka, and Cetina deltas. [ABSTRACT FROM AUTHOR]