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.
Ground deformations (e.g., landslide and subsidence) have substantially risen recently around Penang Island, Malaysia. The development of hillslopes for rapid urbanisation and heavy rainfall has detrimental impacts on Penang Island soil layers. Modelling, simulation, and the development of susceptibility maps were past methods used to predict potential ground deformations of Penang Island. There is no published work on the Interferometry Synthetic Aperture Radar (InSAR) technique, where ground deformation of the region has been holistically studied. This work integrates the Persistent Scatterer InSAR (PS-InSAR) technique with Ground Penetrating Radar (GPR) to monitor the deformation on the island and identify possible subsurface causes for the disturbance. Twenty-four descending Sentinel-1A datasets acquired between 14th July 2017 and 13th October 2018 were processed to monitor and map ground deformation areas with a focus on three selected regions- Batu Feringghi (BF), Paya Terubong (PT), and Tanjung Bungah (TB), where multiple landslides occurred between 2017 and 2018. InSAR results were later analysed using the Statistical Package for the Social Sciences (SPSS) tool and validated by the available Global Positioning System (GPS) analysis. InSAR analyses reveal the mean deformation values of -3.13 mm/yr, -2.76 mm/yr and -4.77 mm/yr for the BF, PT, and TB areas. GPR surveys were conducted with a 300/800 MHz dual-frequency antenna at the three selected study areas. Anomalies (wall cracks, road fissures, cavities, drains, and pipes) detected using GPR profiles correlated well with the permanent scatterer points calculated using the InSAR technique., Kazeem Olukunle Rauff and Ismail Ahmad Abir., and Obsahuje bibliografii
The GRACE satellites have provided gravity field solutions with approximately monthly resolution since April 2002. The monthly solutions enable investigations of the annual, semi-annual and secular mass variations, which mainly occur in a thin layer of the Earth’s surface. By the end of the GRACE science mission in 2017, the time span has increased to 15 years, making the possibility of determining longer-period variations feasible. First attempts to determine multi-annual variations, i.e. periods of some years but less than 10, are presented in this study. A combination of 3 different PSD estimation methods has been used for identifying the regions of multi-annual mass variations. As a result, 8 different areas have been found with significant multi-annual mass variations. The source of multi-annual mass variations in most detected regions can be identified as related to the ENSO cycle. and Kiss Annamária, Földváry Lóránt.