COMPARISON BETWEEN TRADITIONAL AND CONTEMPORARY METHODS FOR DATA RECORDING IN STRUCTURAL GEOLOGY

3D modeling has become a favored way of analyzing 3D data, where users can collect more data with high accuracy in less time than other surveying methods. Technologies capable of providing 3D data such as Terrestrial Laser Scanners (TLS) are often expensive; thus, encouraging users to seek affordable alternatives while achieving the desired accuracies. Characterization of a rock mass requires data from the intact rock along with the discontinuities. The geometrical analysis of the surface enables the calculation of the parameters to characterize the discontinuities and receive other geological and geotechnical data. Remote sensing techniques, such as Terrestrial Laser Scanning (TLS) and Structure from Motion (SfM) technique, provide 3D point clouds that enable the geometrical analysis. The scientific community has been testing both techniques since the 2000s, and companies are introducing their use in their workflows. Today, mobile phones are becoming more capable of 3D modeling, and the most recent iPhone 12/13/14 Pro and iPad Pro provide an integrated LiDAR sensor. In this paper, we explore the digitalization of a rocky slope via the SfM technique generated using drone surveying and via iPhone-13 pro as a comparison to the “old school” data collected from the compass survey. The target of this work is one outcrop of Mica-schist in the north-east part of Macedonia. To capture the surface, compass surveying is used, SfM drone imaging, and two iPhone con-figurations of LiDAR scanner. The data is analyzed using Pix4D and CloudCompare software. The results of iPhone LiDAR and drone SfM scanning show a highly promising match when compared to the compass measurements

Preparation of GIS landslide inventory for the Polog Region

This paper deals with preparation of Geographic Information Systems (GIS) landslide inventoryfor the Polog region. A number of activities were undertaken for this purpose, such as: analysis of own data on landslides, visits of the sites noted in the surveys filled by municipalities, digitizing of landslides from old geological mapsin scale 1:25000, analysis and digitizing of landslides from the archive of the Geological Survey of Macedonia, interviews with employees and retired colleagues from geotechnical companies, analysis of landslides along the channelsof the “Mavrovo” system, visit to the National University in Tetovo and joint site visit, and visits to several geotechnicalcompanies in Macedonia. Since this is the first attempt to create a regional landslide inventory in N. Macedonia, theadopted structure of the inventory is presented in the paper. Moreover, to see what benefits can be gained from theavailability of such inventory some of the most important findings regarding the landslides are presented further. Currently the inventory consists of 136 occurrences, and in time it should be appropriately updated. The main findingsrelated to the distribution and characteristics of the landslides show that future analyses should include preparation oflandslide susceptibility/hazard models both for shallow and deep landslides, as well as for flow-like type of slides. Inthe following stages of investigation, it is planned to analyze a LIDAR (LIght Detection and Ranging) survey that isbeing prepared for the region and incorporate more landslides in the inventory. Also, findings of the InSAR (Interferometric Synthetic Aperture Radar) analysis will be combined with the inventory, which will lead to conclusions on themovement rates of detected sites. The latter two approaches will be presented in future papers