NH6.8

Instability of rock masses is a frequent problem in Italy, which territory is naturally predisposed to a variety of geological hazards. Therefore, issues related to the study of rock masses have always been of primary importance, since their consequences directly affect human lives and the urbanized areas, causing severe losses to society. In order to identify the areas most susceptible to gravity-related phenomena in such settings, the traditional approaches are often not sufficient, and need to be integrated by new tools and techniques aimed at properly and quantitatively describe the structural arrangement of rock masses. These include the use of close range remote sensing techniques. It is now many years that various attempts have been made to standardize processes to extract volumetric shapes from digital data, in order to individuate geometrical features in point clouds and, eventually, to identify discontinuities on rock outcrops. 
We present an attempt to develop and experimentally implement an application of computation codes and software control via command line, to carry out geomechanical investigations on rock masses, starting from 3D surveys. The final goal is to provide reliable results on the likely instability processes in surface and underground settings, as a contribution to the mitigation of the related risks. For this aim, a novel approach is proposed: in order to combine user observation made in situ and on digital results of scanning, our attention was focused on developing non-automatic methods, which could allow, giving a tolerance angle for both dip and dip direction, the extraction of discontinuities on well-structured datasets representing point clouds. This approach could be considered a fully supervised type of classification, because the user can specify the query by placing a numerical input representing an interval of tolerance in degrees; then, it has as output a cluster of planar surfaces belonging to the given interval for each set. The code, organized in a basic software called GEODS (alpha version), which runs on Windows operating systems, also utilizes the results to represent the rocky surfaces on charts and stereographic projections, and is able to calculate standard deviation and mean values of the classified clusters. It is useful to identify the density of each identified discontinuity and to evaluate potential kinematics as well, based on geometric relationships, through analyses carried by a skilled user. This approach was tested at the Cocceio cave, in Campania, southern Italy: this site has historical importance since the Roman age. Reused during World War II, it is now part of a redevelopment project of the Phlegraean Fields, an area renowned for its natural beauty, which includes numerous archaeological sites. At the cave, with this new method, we were able to recognize an additional set, with minor frequency than the other sets, and which was not identified during previous studies. 
As a final result, it is thus expected to contribute in an innovative way to the implementation of alternative and accurate methods in structural analysis and the geomechanical characterization of rock masses.

How to cite: Cardia, S., Palma, B., and Parise, M.: Implementation of computation codes in geostructural surveys to evaluate rock mass stability aimed at the protection of cultural heritage, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-343, https://doi.org/10.5194/egusphere-egu21-343, 2021.

EO4GEO is an Erasmus+ Project aiming at defining a long-term and sustainable strategy to fill the gap between supply of and demand for space/geospatial education and training in the Copernicus domain. To test and validate the approach a series of training actions are ongoing for selected scenarios in three sub-sectors: 1) Integrated Applications, 2) Smart Cities, 3) Climate Change. ISPRA, which includes the Geological Survey of Italy, is contributing to the development of Integrated Applications, coordinating different scenarios fostering the uptake of EO data, services and standardized methodologies of analysis. Available EO data were tested to evaluate their effectiveness and efficiency in different fields (e.g. ground motion monitoring on Cultural Heritage, agro monitoring to support regional decision-making; land change detection, geohazard zoning, risk assessment, etc.). Here we present the preliminary results concerning the InSAR analysis and the development of different training actions on ground motion monitoring on potential slope instabilities affecting Cultural Heritage sites. The selected site is the Roman Thermae at Baia (Naples), being part of the “Parco Archeologico dei Campi Flegrei”, located close to active calderas. The area is characterized by a sequence (from the bottom to the top) of volcanic breccia, pyroclastic deposits and surge deposits; Phlegrean Fields represent an exceptional example of volcanic-related subsidence with unrest cycles characterized by intense ground uplift and lowering. The instability phenomena depend mainly on the acclivity of the top sector of the slope, with the activation of small collapse events, and on the lack of ordinary management and maintenance of the area (e.g. invasive vegetation, absence of drainage system). A preliminary InSAR analysis was performed exploiting ERS datasets (1993–2003), showing regional ground lowering, with deformation rates (5-10 mm/yr) that are consistent with the general down lift cycle affecting the whole area in that that period. Ongoing InSAR data processing are focused on SENTINEL-1 data (April 2016 - August 2020) allowing us to explore most recent evolution of instability phenomena. Data processing has been performed using the SeNtinel’s Application Platform (SNAP-ESA) and the Stanford Method of Persistent Scatterers (StaMPS). The dataset is composed by 79 descending and 81 ascending scenes, and the single master stack contains 76 interferograms from the descending and 80 from the ascending geometry. Additionally, SRTM DEM was used in the interferometric processing. Obtained results clearly show a ground uplifting in the investigated period, with displacement rates ranging between 5 and 10 mm/yr (5.2 mm/yr average value of the study area). Any differential displacement has been observed on the exposed elements of the site. A training module focused on this use case is under development, thus contributing to fill the gap between supply and demand in the Copernicus domain, main goal of the EO4GEO project. The definition of step-by-step methodology from EO data to final processing will be defined and connected to learning outcomes, sectorial and transversal skills contributing to finalize the main goal of the EO4GEO project.

How to cite: Leoni, G., Ferrigno, F., Guarino, P. M., Guerrieri, L., Menniti, F., Pagano, F., Salvatori, M., and Spizzichino, D.: Copernicus InSAR applications for the protection of Cultural Heritage: EO4GEO use case at Baia Roman Thermae, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-9584, https://doi.org/10.5194/egusphere-egu21-9584, 2021.

Cultural heritage is a key element of history as the ancient monuments and archaeological sites enrich today’s societies and help connect us to our cultural origins. The project entitled ''SpaCeborne SAR Interferometry as a Nonivasive tool to assess the vulnerability over Cultural hEritage sites (SCIENCE)'' has as ultimate objective to predict the vulnerability of the archaeological sites to ground deformation in time and space and protect them against natural/man-made damage. The SCIENCE project aims to develop, demonstrate, and validate, in terms of geotechnical local conditions and monuments’ structural health, SAR interferometric techniques to monitor potential ground deformation affecting the archaeological sites and monuments of great importance. 

During the last few years, spaceborne Synthetic Aperture Radar (SAR) interferometry has proven to be a powerful remote sensing tool for detecting and measuring ground deformation and studying the deformation’s impact on man-made structures. It provides centimeter to millimeter resolution and even single buildings/monuments can be mapped from space. Considering the limitations of conventional MT-InSAR techniques, such as Persistent Scatterers Interferometry (PSI), in this project a two-step Tomography-based Persistent Scatterers (PS) Interferometry (Tomo-PSInSAR) approach is proposed for monitoring ground deformation and structural instabilities over the Ancient City Walls (Ming Dynasty) in Nanjing city, China and in the Great Wall in Zhangjiakou, China. The Tomo-PSInSAR is capable of separating overlaid PS in the same location, minimizing the unfavorable layover effects of slant-range imaging in SAR data. Moreover, the demonstrations are performed on well-known test sites in China and in Greece, such as: a) Ming Dynasty City Walls in Nanjing, b) Great Wall in Zhangjiakou, c) Acropolis complex of Athens and d) Heraklion walls (Crete Island), respectively.

In particular, in the framework of SCIENCE project are processed several radar datasets such as Sentinel 1 A & B data of Copernicus program and the high resolution TerraSAR-X data. The products of Persistent Scatterers Interferometry (PSI) are exported in various formats for the identification of the persistent scatterers using high resolution optical images, aerial photographs and fusing with high accuracy Digital Surface Models (DSM). In addition, the validation of the results is taking place through in-situ measurements (geological, geothechnical e.t.c) and data for the cultural heritage sites conditions.

SCIENCE project’s final goal is the risk assessment analysis of the cultural heritage monuments and their surrounding areas aiming to benefit institutions, organizations, stakeholders and private agencies in the cultural heritage domain through the creation of a validated pre-operation non-invasive system and service based on earth observation data supporting end-user needs by the provision knowledge about cultural heritage protection. In conclusion, SCIENCE project is composed by a bilateral consortium of the Greek delegation of Harokopio University of Athens, National Technical University of Athens, Terra Spatium S.A, Ephorate of Antiquities of Heraklion (Crete), Acropolis Restoration Service (Athens) of Ministry of Culture and Sports and by the Chinese delegation of Science Academy of China (Institute of Remote Sensing and Digital Earth) and  International Centre on Space Technologies for Natural and Cultural Heritage (HIST) under the auspices of UNESCO (HIST-UNESCO).

How to cite: Tompolidi, A.-M., Parcharidis, I., Loupasakis, C., Fragkiadakis, M., Soupios, P., Grigorakou, E., Achmet, Z., Kalousi, G., Eleutheriou, V., Michalopoulou, D., Christodoulopoulou, R., Kanaki, E., Mavromati, D., Sythiakaki, V., Elias, P., and Gatsios, T.: SpaCeborne SAR Interferometry as a Noninvasive tool to assess the vulnerability over Cultural hEritage sites (SCIENCE), EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-13397, https://doi.org/10.5194/egusphere-egu21-13397, 2021.

Rock-carved cultural heritage sites are often carved in slopes formed by weak rocks, which due to their peculiar lithological, geotechnical and morpho-structural features are often prone to weathering, deterioration and slope instability issues. In this context the use of advanced close-range remote sensing (RS) techniques, such as Infrared Thermography (IRT) and Unmanned Aerial vehicle-based Digital Photogrammetry (UAV-DP) can be profitably used for the rapid detection of conservation issues (e.g. open fractures, unstable ledges-niches, water seepage and moisture) that can lead to slope instability phenomena. These techniques when combined with traditional methods (e.g. field surveys, laboratory analysis), can provide fundamental data to implement a specific site-specific and inter-disciplinary approach for the sustainable protection and conservation strategies of Rock-carved cultural heritage sites. In this paper some examples of conservation problems in several rupestrian sites characterized by different geological contexts, from the mountainous regions of Georgia to the ancient city of Petra in Jordan, are presented, with the aim of evaluating the potential of the proposed approach integrated approach. The final aim is to provide conservators, practitioners and local authorities with a useful versatile and low-cost methodology, to be profitably used in management plans of rock carved sites.

How to cite: Frodella, W., Elashvili, M., Spizzichino, D., Gigli, G., Nadaraia, A., Giorgi Kirkitadze, G., Adikashvili, L., Margottini, C., Antidze, N., and Casagli, N.: Application of close-range remote sensing techniques for assessing landslide hazard in rock-carved cultural heritage sites, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-15942, https://doi.org/10.5194/egusphere-egu21-15942, 2021.