The paper presents the results of fieldwork and geodetic surveys carried out on a landslide in Wleń (Western Sudetes, Izerskie Foothills). This reactivated landslide occured firstly in 2011 and later on 16th July 2016, following heavy rainfall in the Lower Silesia region, and covered an area of ca. 1100 m2 above the renovated “Leśny Dwór” guesthouse in Wleń town. The main scarp of the landslide is built of strongly deformed Upper Permian (Zechstein) heterolithic deposits, composing the marginal part of the Wleń Graben - a NW-SE elongated, tectonic sub-unit within the North Sudetic Synclinorium. The landslide was a consequence of undercutting of steep slopes of the Bóbr River valley by anthropogenic activities and loading of the slope surface by blocks and pedestrian paths in the vicinity of the guesthouse. Monitoring of landslide activity was performed using the initial surface model of the slope subjected to mass movements, LiDAR elevation data, as well as 3D point cloud data from a non-metric camera on an Unmanned Aerial Vehicle (UAV). They were used to construct digital elevation models (DEMs) of the area covered by the landslide. The DEM from photogrammetric UAV data was processed using Structure from Motion (SfM) technology. The obtained dataset was verified by additional measurement series from terrestrial laser scanning (TLS). and Kowalski Aleksander, Wajs Jaroslaw, Kasza Damian.
We analysed a nearly 133-km-long portion of the Sudetic Marginal Fault (SMF) in Poland (99.7 km) and the Czech Republic (33.8 km), comprised between Złotoryja in the NW and Jesenik in the SE. The fault trace has been subdivided into fifteen segments showing different orientation (N29°W to N56°W, and even N111°W SE of Złoty Stok), geological setting, length (8.8-22.9 km in Poland and 1.4-7.5 km in the Czech Republic), and height of the fault- and fault-line scarps (5-75 m to 200-360 m). Orientation of the entire fault trace approaches N41° W, and the mountain front sinuosity amounts to 1.051. Individual fault segments bear a flight of two to five tiers of triangular facets, showing differentiated state of preservation and degree of erosional remodelling. The highest triangular facets are confined to Rychlebské (Złote) and Sowie Mts. This tiering points to at least five episodes of uplift of the SMF footwall, starting shortly after 31 Ma, i.e. after basalts of the Sichów Hills area were displaced by the fault, and most probably postdating 7-5 Ma time interval, during which rapid cooling and exhumation of the Sowie Góry Mts. massif took place. Morphometric parameters of 244 small catchment areas of streams that dissect the fault scarp include, i.a. elongation, relief, and average slope of individual catchment areas, together with values of the valley flo or width to valley height ratios. These figures point to moderate tectonic activity of the SMF and allow us to conclude about Quaternary uplift, particularly important in the Sowie and Rychlebské (Złote) segments., Janusz Badura, Witold Zuchiewicz, Petra Štěpančiková, Bogusław Przybylski, Bernard Kontny and Stefan Cacoń., and Obsahuje bibliografické odkazy