VGC 2023 - Unveiling the dynamic Earth with digital methods: 5th Virtual Geoscience Conference: Book of Abstracts

Conference proceedings of the 5th Virtual Geoscience Conference, 21-22 September 2023, held in Dresden. The VGC is a multidisciplinary forum for researchers in geoscience, geomatics and related disciplines to share their latest developments and applications.:Short Courses 9 Workshops Stream 1 10 Workshop Stream 2 11 Workshop Stream 3 12 Session 1 – Point Cloud Processing: Workflows, Geometry & Semantics 14 Session 2 – Visualisation, communication & Teaching 27 Session 3 – Applying Machine Learning in Geosciences 36 Session 4 – Digital Outcrop Characterisation & Analysis 49 Session 5 – Airborne & Remote Mapping 58 Session 6 – Recent Developments in Geomorphic Process and Hazard Monitoring 69 Session 7 – Applications in Hydrology & Ecology 82 Poster Contributions 9

Visualization of Time-Varying Data from Atomistic Simulations and Computational Fluid Dynamics

Time-varying data from simulations of dynamical systems are rich in spatio-temporal information. A key challenge is how to analyze such data for extracting useful information from the data and displaying spatially evolving features in the space-time domain of interest. We develop/implement multiple approaches toward visualization-based analysis of time-varying data obtained from two common types of dynamical simulations: molecular dynamics (MD) and computational fluid dynamics (CFD). We also make application case studies. Parallel first-principles molecular dynamics simulations produce massive amounts of time-varying three-dimensional scattered data representing atomic (molecular) configurations for material system being simulated. Rendering the atomic position-time series along with the extracted additional information helps us understand the microscopic processes in complex material system at atomic length and time scales. Radial distribution functions, coordination environments, and clusters are computed and rendered for visualizing structural behavior of the simulated material systems. Atom (particle) trajectories and displacement data are extracted and rendered for visualizing dynamical behavior of the system. While improving our atomistic visualization system to make it versatile, stable and scalable, we focus mainly on atomic trajectories. Trajectory rendering can represent complete simulation information in a single display; however, trajectories get crowded and the associated clutter/occlusion problem becomes serious for even moderate data size. We present and assess various approaches for clutter reduction including constrained rendering, basic and adaptive position merging, and information encoding. Data model with HDF5 and partial I/O, and GLSL shading are adopted to enhance the rendering speed and quality of the trajectories. For applications, a detailed visualization-based analysis is carried out for simulated silicate melts such as model basalt systems. On the other hand, CFD produces temporally and spatially resolved numerical data for fluid systems consisting of a million to tens of millions of cells (mesh points). We implement time surfaces (in particular, evolving surfaces of spheres) for visualizing the vector (flow) field to study the simulated mixing of fluids in the stirred tank

Dendroarchaeology applied to the Portuguese cultural heritage between the XV and XIX enturies: paintings and musical instruments as witnesses of artwork and wood trades between Portugal and Europe

Doutoramento em Engenharia Florestal e dos Recursos Naturais / Instituto Superior de Agronomia. Universidade de LisboaThe current study focuses on the dendrochronological dating of seventy Portuguese and foreign artworks from the XV to the XIX centuries from public and private collections. Among the artworks examined are a collection of 34 Portuguese and Flemish paintings, as well as 36 musical instruments of Portuguese and foreign construction. The study investigates the wood's provenance within the historical context of Portuguese maritime commerce with Europe. This research aims to develop a reference chronology, which will be useful for future dendrochronological studies, with a focus on artworks on Baltic oak wood support. The adopted methodology took into consideration the impossibility of obtaining samples from artworks and musical instruments, as well as the restrictions to their handling. Therefore, the dendrochronological analysis was based on direct observation using photographic and video material adapted to the size and shape of each piece, followed by statistical processing by ARSTAN, COFECHA, TRiCYCLE, and TSAPWIN software. The dating of each piece and the study of the dendroprovenance used public and restricted access reference chronology databases. The results obtained from the study of the support of Portuguese and Flemish paintings reinforce their chronological attributions and confirm the use of Baltic oak. The dendrochronological data obtained from these pieces, in conjunction with data provided by the IJF-DGPC and research projects conducted by the CEF-ISA, enabled the construction of a reference chronology spanning between the years 1149 to 1599. The pioneering dendrochronological study on Portuguese violins, cellos, and pianofortes from the XVIII and XIX centuries corroborates the historical dates inscribed on the respective musical instruments. It also revealed that the Portuguese workshops used woods from the Alpine region of Switzerland, Germany, Austria, and Italy, which is consistent with the several historical sources on the Portuguese maritime trade with Europe. In conclusion, dendrochronology based on artworks enabled the construction of historical knowledge, as well as the interpretation of paintings and musical instruments as evidence of goods traded between Portugal and Europe between the XV and XIX centuries.N/

Spatial variability of aircraft-measured surface energy fluxes in permafrost landscapes

Arctic ecosystems are undergoing a very rapid change due to global warming and their response to climate change has important implications for the global energy budget. Therefore, it is crucial to understand how energy fluxes in the Arctic will respond to any changes in climate related parameters. However, attribution of these responses is challenging because measured fluxes are the sum of multiple processes that respond differently to environmental factors. Here, we present the potential of environmental response functions for quantitatively linking energy flux observations over high latitude permafrost wetlands to environmental drivers in the flux footprints. We used the research aircraft POLAR 5 equipped with a turbulence probe and fast temperature and humidity sensors to measure turbulent energy fluxes along flight tracks across the Alaskan North Slope with the aim to extrapolate the airborne eddy covariance flux measurements from their specific footprint to the entire North Slope. After thorough data pre-processing, wavelet transforms are used to improve spatial discretization of flux observations in order to relate them to biophysically relevant surface properties in the flux footprint. Boosted regression trees are then employed to extract and quantify the functional relationships between the energy fluxes and environmental drivers. Finally, the resulting environmental response functions are used to extrapolate the sensible heat and water vapor exchange over spatio-temporally explicit grids of the Alaskan North Slope. Additionally, simulations from the Weather Research and Forecasting (WRF) model were used to explore the dynamics of the atmospheric boundary layer and to examine results of our extrapolation

Forschungsbericht Universität Mannheim 2006 / 2007

Sie erhalten darin zum einen zusammenfassende Darstellungen zu den Forschungsschwerpunkten und Forschungsprofilen der Universität und deren Entwicklung in der Forschung. Zum anderen gibt der Forschungsbericht einen Überblick über die Publikationen und Forschungsprojekte der Lehrstühle, Professuren und zentralen Forschungseinrichtungen. Diese werden ergänzt um Angaben zur Organisation von Forschungsveranstaltungen, der Mitwirkung in Forschungsausschüssen, einer Übersicht zu den für Forschungszwecke eingeworbenen Drittmitteln, zu den Promotionen und Habilitationen, zu Preisen und Ehrungen und zu Förderern der Universität Mannheim. Darin zeigt sich die Bandbreite und Vielseitigkeit der Forschungsaktivitäten und deren Erfolg auf nationaler und internationaler Ebene

Apports d’une approche combinant mesures in situ et télédétection optique pour le suivi des glaciers de montagne : cas des Andes tropicales et des Alpes occidentales

L’étude des processus glaciaires nécessite un suivi de terrain pour comprendre les interactions entre les glaciers et leur environnement à des échelles fines de temps et d’espace. Un petit nombre de glaciers de référence est instrumenté dans différentes régions climatiques à l’échelle mondiale, permettant un suivi de leur bilan de masse et dans certains cas de leur bilan d’énergie de surface. Cependant, ce petit nombre constitue un obstacle à la connaissance de la relation entre les changements climatiques et l’évolution des glaciers à l’échelle d’un massif ou d’une région climatique. Il en est de même pour la quantification de la contribution des glaciers aux ressources en eau et au fonctionnement des bassins versants de haute altitude. Ainsi, aboutir à une prise en compte des processus et des changements glaciaires à l’échelle régionale nécessite un changement d’approche, et la télédétection s’avère être l’outil le plus approprié. Ce suivi à plusieurs niveaux est la stratégie mise en œuvre par le SO/SOERE GLACIOCLIM (INSU, IRD, OSUG, AllEnvi) et s’inscrit dans le cadre de la stratégie de surveillance établie internationalement par le Global Terrestrial Network for Glaciers (IUGG/IACS).Les résultats récents obtenus dans les Andes tropicales et Alpes occidentales montrent les avantages à combiner les informations recueillies à partir de «glaciers de référence» et celles obtenues par télédétection à l'échelle du massif, afin de mieux comprendre les causes de l’accélération de la diminution des glaciers au cours des dernières décennies. Ceci a notamment été rendu possible par le développement d’une méthode permettant de quantifier le bilan de masse annuel d’un glacier à partir de sa ligne d’équilibre mesurée par télédétection.Enfin, la question du devenir des glaciers de montagne sera discutée. Simuler l’évolution à venir des glaciers nécessite de connaitre les épaisseurs de glace pour l’ensemble du glacier, de simuler les bilans de masse pour les années/décennies futures, et de prendre en compte la dynamique d’écoulement du glacier. Nous verrons quel est l’état des connaissances et des développements méthodologiques pour ces trois pré-requis indispensables, et comment les limites actuelles peuvent être outrepassées afin d’améliorer les estimations du devenir des glaciers de montagne