SFM-MVS photogrammetry for rockfall analysis and hazard assessment along the ancient roman via Flaminia road at the Furlo gorge (Italy)

Rockfall events represent significant hazards for areas characterized by high and steep slopes and therefore effective mitigation controls are essential to control their effect. There are a lot of examples all over the world of anthropic areas at risk because of their proximity to a rock slope. A rockfall runout analysis is a typical 3D problem, but for many years, because of the lack of specific software, powerful computers, and economic reasons, a 2D approach was normally adopted. However, in recent years the use of 3D software has become quite widespread and different runout working approaches have been developed. The contribution and potential use of photogrammetry in this context is undoubtedly great. This paper describes the application of a 3D hybrid working approach, which considers the integrated use of traditional geological methods, Terrestrial Laser Scanning, and drone based Digital Photogrammetry. Such approach was undertaken in order to perform the study of rockfall runout and geological hazard in a natural slope in Italy in correspondence of an archaeological area. Results show the rockfall hazard in the study area and highlights the importance of using photogrammetry for the correct and complete geometrical reconstruction of slope, joints, and block geometries, which is essential for the analysis and design of proper remediation measures

Research of old rockfalls using LiDAR data

Diplomová práce se zabývá problematikou detekce a modelováním starého skalního řícení z LiDARových dat. Jako zájmové území byla vybrána lokalita Dlouhý důl nacházející se v Národním parku České Švýcarsko. Hlavním cílem práce je zmapování, zpětná analýza a modelování skalního řícení. V rámci práce byl navržen a otestován celkový postup pro modelování skalního řícení pomocí open source softwarů. Dílčím cílem práce bylo zpracování laserových dat do podoby bodového mračna a provedení kontroly kvality dat. Stěžejní částí bylo stanovit vhodný zorný úhel. Pro předzpracování dat byl použit software PosPac a RiProcess. Dalším dílčím cílem byla tvorba DMR, který je zásadní pro detekci a modelování skalního řícení. Vedlejším cílem byla filtrace a segmentace bodového mračna. To bylo testováno ve dvou softwarech CloudCompare a OPALS. Pro vyhodnocení a modelování skalního řícení je použit QGIS s pluginem QPROTO. Dílčím cílem je literární rešerše věnující se vývoji a metodám skalního řícení. V teoretické části je popsána definice skalního řícení včetně podmínek, které se podílejí na vzniku svahových pohybů, dále pak LiDAR, filtrace a segmentace bodového mračna včetně používaných metod. V praktické části je popsán historický vývoj zájmového území, použitá data a předzpracování a zpracování dat. Výsledkem jsou...This thesis addresses the issue of detecting and modeling old rockfalls using LiDAR data. The study area chosen for investigation is Dlouhý Důl, located in the České Švýcarsko National Park. The main objective of this research is to map, retrospectively analyze, and model historical rockfall events. To achieve this, a comprehensive workflow for modeling rockfalls using open-source software was proposed and tested. The specific goals of the thesis included processing the laser data to create a point cloud and conducting data quality checks. A crucial aspect was determining the optimal viewing angle for analysis. The software PosPac and RiProcess were utilized for data preprocessing. Another important step was the generation of a Digital Relief Model (DMR), essential for detecting and modeling rockfalls. The point cloud filtering and segmentation were pursued as ancillary objectives and tested using two software applications, CloudCompare and OPALS. For the evaluation and modeling of rockfalls, QGIS with the QPROTO plugin was employed. Additionally, a literature review on the development and methodologies related to rockfalls was conducted. The theoretical section describes the definition of rockfalls, including the factors contributing to slope movements, as well as LiDAR technology, point cloud...Katedra aplikované geoinformatiky a kartografieDepartment of Applied Geoinformatics and CartographyPřírodovědecká fakultaFaculty of Scienc

Application of unmanned aerial vehicle data and discrete fracture network models for improved rockfall simulations

This is the final version. Available from the publisher via the DOI in this record.In this research, we present a new approach to define the distribution of block volumes during rockfall simulations. Unmanned aerial vehicles (UAVs) are utilized to generate high-accuracy 3D models of the inaccessible SW flank of the Mount Rava (Italy), to provide improved definition of data gathered from conventional geomechanical surveys and to also denote important changes in the fracture intensity. These changes are likely related to the variation of the bedding thickness and to the presence of fracture corridors in fault damage zones in some areas of the slope. The dataset obtained integrating UAV and conventional surveys is then utilized to create and validate two accurate 3D discrete fracture network models, representative of high and low fracture intensity areas, respectively. From these, the ranges of block volumes characterizing the in situ rock mass are extracted, providing important input for rockfall simulations. Initially, rockfall simulations were performed assuming a uniform block volume variation for each release cell. However, subsequent simulations used a more realistic nonuniform distribution of block volumes, based on the relative block volume frequency extracted from discrete fracture network (DFN) models. The results of the simulations were validated against recent rockfall events and show that it is possible to integrate into rockfall simulations a more realistic relative frequency distribution of block volumes using the results of DFN analyses

UAVs for the Environmental Sciences

This book gives an overview of the usage of UAVs in environmental sciences covering technical basics, data acquisition with different sensors, data processing schemes and illustrating various examples of application