Matej Masný

On February 6, 1924, a catastrophic snow avalanche struck the settlement of Rybie in the Veľká Fatra Mountains, remaining the deadliest avalanche disaster on record in Slovakia and the entire Western Carpathians, with 18 fatalities. Historical documentation offers limited quantitative data on the event’s parameters, including release zone locations and snow depths, although the positions of destroyed buildings can still be partially identified in the field. Leveraging recent advances in high-resolution terrain data (e.g., LiDAR), GIS-based tools for identifying potential release areas (PRA), and dynamic simulation models (AvaFrame and RAMMS::Avalanche), this study performs a back-calculation of the 1924 avalanche. A series of simulations were conducted based on delineated PRAs and analyzed against a critical destructive pressure threshold of 20 kPa at the locations of the former buildings. The results identify an avalanche with a crown height of at least 1.6 m as the most probable scenario. These findings contribute to the reassessment of the site’s future avalanche vulnerability and provide a methodological contribution to avalanche modeling and historical accident reconstruction.

Recently, the cultivation of fast-growing tree (FGT) plantations has gained importance due to the growing energy and climate crisis. FGT plantations have the potential to reduce carbon footprints and lower greenhouse gas emissions by utilization of local renewable energy sources. Effective monitoring of above-ground biomass (AGB) is crucial for the successful management of these plantations. Standard methods for estimating AGB rely on easily measurable parameters, such as Diameter at Breast Height (DBH) and tree height, which are highly correlated with AGB. Traditional methods for measuring DBH include measuring tapes and calipers; however, these techniques can be labor-intensive, time-consuming, and limited when assessing large areas. Innovative approaches, such as photogrammetry, terrestrial laser scanning (TLS), mobile laser scanning (MLS), and iPhone LiDAR scanning, can complement these traditional methods by generating point clouds that can be used for extracting dendrometric parameters. This study evaluates the effectiveness of TLS (RIEGL VZ-1000), MLS (Stonex X120 GO), iPhone LiDAR (iPhone 13 Pro MAX), and terrestrial photogrammetry (iPhone 13 Pro MAX) for estimating DBH in a Paulownia plantation. Each technology has limitations: while TLS offers high accuracy, it is also expensive and time-consuming. Similarly, MLS is relatively costly. On the other hand, iPhone LiDAR and terrestrial photogrammetry are more affordable alternatives; however, the iPhone LiDAR has a limited scanning range, and photogrammetry requires considerable time and expertise for data collection and processing. The primary objective of this study was to evaluate these technologies based on their accuracy in DBH estimation, ease of use, data collection, processing time, and cost within the ideal conditions of a Paulownia plantation (characterized by the absence of understory, level ground, and uniform tree shape and spacing). The aim was to determine whether traditional methods could be replaced with more efficient, quicker, easier, and cost-effective alternatives. Results indicated that TLS, MLS, and photogrammetry provided similar DBH estimation accuracies, with root mean square error (RMSE) values between 0.7 and 0.72 cm and relative RMSE values between 2.87 % and 2.95 %. In contrast, the iPhone LiDAR was the least accurate, with an RMSE of 1.7 cm and an rRMSE of 6.96 %. This study demonstrates that all evaluated technologies offer sufficient accuracy for DBH estimation, although TLS and MLS capture additional parameters at a higher cost. Therefore, TLS is impractical for DBH estimation in plantation environments due to its high cost, time, and labor demands. While less expensive, terrestrial photogrammetry also requires significant time investment and operator expertise. Despite its cost, MLS achieved the best results among all the evaluated technologies and proved to be the fastest and relatively simple. If cost is a concern, the best solution for DBH estimation in an FGT plantation environment would be iPhone LiDAR scanning. It represents the most affordable option with satisfactory accuracy and ease of use.This abstract is based upon work from COST Action 3DForEcoTech, CA20118, supported by COST (European Cooperation in Science and Technology) and APVV 20 0391 Monitoring of forest stands in three-dimensional space and time by innovative close-range approaches.

Technosols from the heap of the abandoned Italian Cu deposit Caporciano contain important amounts of potentially toxic elements (Cr _tot. , Co, Ni, Cu, Zn, As, Cd and Pb). Copper contents exceed the Italian law limits for industrial/commercial sites. The studied metals in Pinus sylvestris and Quercus petraea (Matt.) Liebl. show strategy of excluders (bioconcentration factor < 1.0) except Ni and Pb (calculated for branches and leaves in Pinus sylvestris ) while the translocation factor indicates preferential metal accumulation to leaves/needles (translocation factor > 1.0) in both plant speciments.At the heap the contents of the chlorophyll in leaves in the photosynthetic tissues of Quercus petraea (Matt.) Liebl. (8.56 CCI—chlorophyll content index) are significantly lower as those measured at reference area (17.71 CCI). The goal of the study is to use a modified methodology for the fractional analysis of soils for the determination of the potential bioavailability of potentially toxic elements in six steps. The innovative steps of sequential analysis are adapted with respect to the release of PTEs from the clay mineral surfaces. (fraction I: 1 M ammonium acetate at pH 7; fraction II: ammonium acetate at pH 5; fraction III: H ₂ O ₂ in ammonium acetate buffer solution; fraction IV: acidic 0.2 M ammonium oxalate (pH 3.2); fraction V: 0.2 M ammonium oxalate and 0.1 M ascorbic acid mixture; fraction VI: 0.5 M ammonium acetate; pH 6). The best bioavailable metals are Cd, Cu, Zn and Pb. The obtained results enable international comparison with similar Cu-deposits.

Our work aimed to compare the chip pile volumes calculated by laser ground scanning, UAV technology, and laser ground measurement and also to determine the accuracy, speed, and economic efficiency of each method. The large chip pile was measured in seven different ways: band measurement, laser measurement with Vertex, global navigation satellite system, handheld mobile laser scanner, terrestrial laser scanner, drone, and smartphone with a light detection and ranging sensor. All the methods were compared in terms of accuracy, price, user-friendliness, and time required to obtain results. The calculated pile volume, depending on the method, varied from 2588 to 3362 m³. The most accurate results were provided by the terrestrial laser scanning method, which, however, was the most expensive and the most demanding in terms of collecting and evaluating the results. From a time and economic point of view, the most effective methods were UAVs and smartphones with LiDAR.

Slovenská akadémia vied vykonáva špičkový základný výskum, dlhodobý strategický a aplikovaný výskum a vývoj a poskytuje prístup k vedeckej infraštruktúre.

Water retention is an important hydrological ecosystem service of active floodplain soils. The aim of the study was to evaluate the soil chemical, physical, and hydrological properties in Fluvisols in three different ecosystems that have an impact on water retention hydrological ecosystem services (WRHESs). We selected 16 localities along the Štiavnica River in Central Slovakia, 8 located in riparian zones (RZ), 5 in arable lands (AL), and 3 in grasslands (GL). Soil samples were collected from two layers (0–10 and 20–30 cm). In the laboratory, the soil physical (soil texture) and soil chemical properties (pH, soil organic carbon content, humic and fulvic acid ratio) were determined. Using undisturbed soil samples, the soil physical characteristics (particle density, bulk density, porosity, and actual soil moisture–SMa) were measured. With the help of pedotransfer functions, hydrological soil properties (field water capacity–FWC, wilting point–WP, available water capacity–AWC) were estimated. The recorded properties differed between the localities, ecosystems, and two layers. The SMa values showed a higher soil water retention potential of extensively used ecosystems, such as GL and RZ. However, the hydrological properties estimated by pedotransfer functions (FWC, WP, AWC) showed a higher soil water retention potential in AL localities. This indicated that for calculations, selected pedotransfer functions (particle size fractions, organic matter, and bulk density) and other soil or ecosystem properties (e.g., vegetation cover, meteorological conditions) have an impact on WRHESs. One such soil factor can be the quality of organic matter. On the basis of the results of the ANOVA, significant differences emerged between the different ecosystems for selected basic chemical, physical, and hydrological properties. The effect of the soil layer on the soil properties was revealed only in the case of SOC. The results indicated the effect of different ecosystems on soil WRHES and the importance of extensively managed ecosystems, such as RZ and GL. From this point of view, the reduction in the RZ and GL areas during a period of the last 70 years is negative. The findings should be taken into account in future sustainable floodplain management and landscape architecture.

Land change models offer an essential resource for predicting future land use and land cover (LULC) change. Model accuracy and proper validation are essential for supporting the decision process related to landscape planning. The paper's main aim is to test and analyse the accuracy of the LULC trend model based on the land cover changes from 1990 to 2012. The Land Change Modeler (TerrSet) and Corine Land Cover data for the area of Slovakia was used. The obtained model was compared with the real changes captured in the next period (2012 to 2018). Different model reliability was observed in different types of land cover. From a relatively low level of reliability to a level of more than 80% concordance. Results pointed on significance and limits of tools for predictive modelling in a specific type of landscape (included very heterogeneous natural conditions) after period of strong institutional changes impact on LULC.

Aim of the study The aim of this paper is to analyze and assess the land cover change in three transects in Slovakia by applying the coefficient of ecological stability and the coefficient of anthropogenic impact in four different time horizons (1950, 1990, 2000, and 2020). Based on the specific natural and socio-economic factors influencing landscape formation and change, we chose three transects from the territory of Slovakia as study areas. The study areas are located in western Slovakia (transect called Zahorie: Rudava - Bukova), central Slovakia (transect called Turiec: Martin - Moskovec), and eastern Slovakia (transect called Poloniny: Stakcin - Ruske). Material and methods Several methodological tools have been created to express the level of ecological stability of a given territory. In our study, we used the coefficient of ecological stability (CES). The intensity of changes in the landscape as a result of human activity was also described through the coefficient of anthropogenic influence (CAI). Results and conclusions The results of CES and CAI indicate a similar situation in case of the Zahorie: Rudava - Bukova transect and the Poloniny: Stakcin - Ruske transect. For the Poloniny: Stakcin - Ruske transect, the CES values are significantly higher than 1.21, which is a landscape with high ecological stability, and the CAI values are close to 0, which also represents a landscape with a minimal intensity of changes due to human activity. In the case of the Zahorie: Rudava - Bukova transect it is similar, but the CES values do not reach such high values as in the case of the Poloniny: Stakcin - Ruske transect, which is mainly influenced by the fact that the Poloniny: Stakcin - Ruske transect passes through a protected area of the Poloniny National Park. In the case of the Turiec: Martin - Moskovec transect, there is no correspondence between the CAI and CES values, as the CAI values are less than 1 (the highest value is 0.46), which represents a landscape with a minimal intensity of changes due to human activity. However, the results of CES are values lower than 0.8, which represents a landscape with low ecological stability.

UAV-based photogrammetry has many applications today. Measuring of snow depth using Structure-from-Motion (SfM) techniques is one of them. Determining the depth of snow is very important for a wide range of scientific research activities. In the alpine environment, this information is crucial, especially in the sphere of risk management (snow avalanches). The main aim of this study is to test the applicability of fixed-wing UAV with RTK technology in real alpine conditions to determine snow depth. The territory in West Tatras as a part of Tatra Mountains (Western Carpathians) in the northern part of Slovakia was analyzed. The study area covers more than 1.2 km² with an elevation of almost 900 m and it is characterized by frequent occurrence of snow avalanches. It was found that the use of different filtering modes (at the level point cloud generation) had no distinct (statistically significant) effect on the result. On the other hand, the significant influence of vegetation characteristics was confirmed. Determination of snow depth based on seasonal digital surface model subtraction can be affected by the process of vegetation compression. The results also point on the importance of RTK methods when mapping areas where it is not possible to place ground control points.