NH6.8

Remote Sensing & Cultural Heritage

Tangible Cultural Heritage (TCH) plays a key role in building the memory and roots of human society. Unfortunately, TCH sites are often threatened by soil erosion and natural hazards (e.g. landslides, earthquakes, flooding, tropical storms, forest fire); further damage can also arise from the fragility of the site’s structures and materials with respect to anthropogenic hazards (destructive sabotage, war) and incorrect urban planning. The protection and conservation of TCH sites are pressing issues not only for the conservators/scientist’s community but for the whole society. For a correct conservation strategy it is necessary to implement a specific inter-disciplinary approach, that should be planned considering the site characteristics (topography, geomorphological-geological setting) and typology of the related hazard. In this perspective the use of remote sensing (RS) techniques applied from spaceborne, airborne and ground-based to UAV platforms (including, but not limited to, Radar interferometry, Lidar, Digital photogrammetry, Optical and Infrared imaging) combined with detailed field surveys, sample laboratory analysis, geotechnical and geophysical analysis, can provide the fundamental data for the implementation of mapping products and geodatabases, especially in developing countries with limited data, to be used as a starting point for TCH management plans. The goal of this Session is to gather high-quality original contributions and case studies applications on the use of RS techniques for protection and conservation of tangible Cultural and Natural Heritage sites (these include but are not limited to the UNESCO World Heritage and Tentative Lists) for risk mitigation practices and management plans.

Convener: William Frodella | Co-conveners: Andrea Ciampalini, Mikheil Elashvili, Daniele Spizzichino
vPICO presentations
| Thu, 29 Apr, 11:45–12:30 (CEST)

Session assets

Session materials Session summary

vPICO presentations: Thu, 29 Apr

Chairpersons: William Frodella, Daniele Spizzichino , Mikheil Elashvili
11:45–11:50
11:50–11:55
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EGU21-343
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ECS
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solicited
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Highlight
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Stefano Cardia, Biagio Palma, and Mario Parise

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, 2020.

11:55–11:57
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EGU21-1110
Renato Somma, Alfredo Trocciola, Daniele Spizzichino, Alessandro Fedele, Gabriele Leoni, Fabio Matano, Karen Holmberg, Claudia Troise, Giuseppe De Natale, Maria Cristina Napolitano, and Claudio Margottini

The archaeological site of Villa Arianna - located on Varano Hill, south of Vesuvius - offer tantalizing information regarding first-century AD resilience to hydrogeological risk. Additionally, the site provides an important test case for mitigation efforts of current and future geo-hazard. Villa Arianna, notable in particular for its wall frescoes, is part of a complex of Roman villas built between 89 BC and AD 79 in the ancient coastal resort area of Stabiae. This villa complex is located on a morphological terrace that separates the ruins from the present-day urban center of Castellammare di Stabia. The Varano hill is formed of alternating pyroclastic deposits, from the Vesuvius Complex, and alluvial sediments, from the Sarno River. The area, in AD 79, was completely covered by PDCs from the Plinian eruption of Vesuvius. Due to the geomorphological structure the slope is prone to slope instability phenomena that are mainly represented by earth and debris flows, usually triggered by heavy rainfall. The susceptibility is worsened by changes in hydraulic and land-use conditions mainly caused by lack of maintenance of mitigation works. Villa Arianna is the subject of a joint pilot project of the INGV-ENEA-ISPRA that includes non-invasive monitoring techniques such as the use of UAVs to study the areas of the slope at higher risk of instability. The project, in particular, seeks to implement innovative mitigation solutions that are non-destructive to the cultural heritage. UAVs represent the fastest way to produce high-resolution 3D models of large sites and allow archaeologists to collect accurate spatial data that can be used for 3D GIS analyses. Through this pilot project, we have used detailed 3D models and high-resolution ortho-images for new analyses and documentation of the site and to map the slope instabilities that threatens the Villa Arianna site. Through multi-temporal analyses of different data acquisitions, we intend to define the detailed morphological evolution of the entire Varano slope. These analyses will allow us to highlight priority areas for future low-impact mitigation interventions.

How to cite: Somma, R., Trocciola, A., Spizzichino, D., Fedele, A., Leoni, G., Matano, F., Holmberg, K., Troise, C., De Natale, G., Napolitano, M. C., and Margottini, C.: Unmanned Aerial Vehicle (UAV) time-lapse monitoring of the instability processes affecting Varano Hill: A case study of the ancient Roman site of Villa Arianna, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-1110, https://doi.org/10.5194/egusphere-egu21-1110, 2021.

11:57–11:59
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EGU21-8676
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ECS
Tim Baxter, Martin Coombes, and Heather Viles

Maritime built heritage is threatened by natural hazards and human activities around the world. Likewise, marine wildlife is increasingly threatened by the effects of climate change and human development. Due to their age and traditional construction, maritime built heritage (e.g. historic harbours) may provide unique habitats for diverse assemblages of marine wildlife. Yet, as aspects of built heritage are often missing in assessments of marine infrastructure, identifying which heritage assets have the potential to provide the greatest ecological benefits remains a challenge. An improved understanding of the ecological importance of maritime built heritage can enhance arguments for its continued protection, maintenance and repair. At the same time, this may present new opportunities to conserve important and largely unidentified hotspots of marine biodiversity.

Using preliminary results from the Isles of Scilly, UK, this study presents a novel method for quantifying the full extent of marine engineering structures (including heritage assets) at a regional scale, and for identifying priority structures for joint biodiversity and heritage conservation.

Remote sensing data were considered alongside historic environment data and records of modern coastal defences in a rapid desk-based assessment to create a complete inventory of marine structures along the entire coastline of the Isles of Scilly. In total, 68 structures were recorded (6,180 m in length), with over half registered as heritage assets. LiDAR and aerial photography were used to determine the site characteristics of each structure (e.g. shore position). This allowed for an initial assessment of the potential ecological importance of these structures when considered alongside structural information, including building age and material. By evaluating the ecological potential and heritage value of each structure using a novel scoring system, priorities for conservation and other managed interventions are identified. This includes listed buildings and scheduled monuments that due to their construction features and shore position are most likely to support diverse marine assemblages.

Combined ecological-heritage evaluations incorporating remote sensing datasets allow for the identification of those structures with the greatest potential for the integrated conservation of built heritage and marine wildlife. Research is now needed to develop this method further, ground-truth its outputs, and test its application in other geographical locations and at varying scales.

How to cite: Baxter, T., Coombes, M., and Viles, H.: Maritime built heritage and marine wildlife: Remote sensing as a tool to identify and prioritise integrated conservation in coastal environments, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-8676, https://doi.org/10.5194/egusphere-egu21-8676, 2021.

11:59–12:01
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EGU21-9584
Gabriele Leoni, Federica Ferrigno, Paolo Maria Guarino, Luca Guerrieri, Francesco Menniti, Fabio Pagano, Marida Salvatori, and Daniele Spizzichino

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.

12:01–12:03
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EGU21-10902
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ECS
Yunus Esel, Ercan Erkul, Detlef Schulte-Kortnack, Christian Leonhardt, and Thomas Meier

The preservation of culturally significant buildings is challenging due to the variety of historical building materials, the often complex building history and damage patterns. It is usually associated with high financial costs. Non-destructive testing may help to plan, optimize, and monitor conservation measures. Here, we report on non-destructive testing of moisture distribution at the Cathedral St. Petri in Schleswig (Germany) using thermography and georadar measurements.  These methods are standard methods in engineering geology and construction. In the field of heritage conservation, however, the application and especially the combination of several of these methods is not yet established.

The walls of the ‘Schwahl’ (a three-sided cloister) show medieval paintings from the 14th century. In the Schwahl, large-scale alterations occur due to gypsum deposits and a shellac coating.   Active thermography measurements were taken before and after test treatments to evaluate the effectiveness of the use of different solvents to remove the shellac and the gypsum deposits. Passive thermography and georadar measurements indicate increased moisture content in the area of the gypsum deposits likely caused by a permeable horizontal sealing barrier below the paintings. Examples of the measurements are shown and the processing of the thermography and georadar measurements including the attenuation analysis are discussed.

How to cite: Esel, Y., Erkul, E., Schulte-Kortnack, D., Leonhardt, C., and Meier, T.: Geophysical investigations of medieval paintings at St. Petri Cathedral Schleswig (Germany) with georadar and thermography, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-10902, https://doi.org/10.5194/egusphere-egu21-10902, 2021.

12:03–12:05
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EGU21-13397
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ECS
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Athanasia-Maria Tompolidi, Issaak Parcharidis, Constantinos Loupasakis, Michalis Fragkiadakis, Pantelis Soupios, Eleni Grigorakou, Zeinep Achmet, Georgia Kalousi, Vasiliki Eleutheriou, Dionysia Michalopoulou, Rozalia Christodoulopoulou, Eleni Kanaki, Dionysia Mavromati, Vassiliki Sythiakaki, Panagiotis Elias, and Theodoros Gatsios

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.

12:05–12:10
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EGU21-13978
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ECS
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solicited
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Highlight
Ruma Adhikari

The growing flood events and the associated risk in heritage structures are an increasingly crucial issue for India, which possesses heritage richness. However, it is more critical for developing countries where often the case is poorly understudied. Hampi, also referred to as the Group of Monuments, is a UNESCO World Heritage Site located in east-central Karnataka, India. Several monuments at the heritage site of Hampi along the Tungabhadra river are inundated several times within a year. After every flood, the river changes its course, inundating areas that were supposed to be safe from floods. The post-flood silt deposition over structures makes them more vulnerable to erosion and distortion. So, to restore, mapping of flooded structures is crucial. The changes in the cultural landscape should be monitored on a spatial and temporal basis. Rapid and precise extraction of the flooded areas is key to supporting emergency-response planning and providing damage assessment in spatial and temporal measurements to monuments.

The European Space Agency's (ESA) Copernicus is one of the most ambitious Earth Observation (EO) programs having operational satellite constellations providing continuous, accurate, and easily accessible satellite data for the entire globe. This study demonstrates the use of Google Earth Engine (GEE) and Dual polarized (VV and VH) Sentinel-1 Synthetic Aperture Radar (SAR) data for mapping flooded areas. Change detection and thresholding methodology have been adopted in Google Earth Engine (Python-based) Platform to determine the extent of flooding using multiple Sentinel‐1 SAR images captured before and after the floods of August 2019 in Hampi. Thresholding is one of the most commonly adopted SAR imagery methods to discriminate between water and non-water surface. An automatic thresholding approach using the Otsu algorithm is optimal for large thresholding objects from the background, which means that it is strongly dependent on the histogram's bimodality. SAR Polarimetry backscatter properties being used effectively for stone structure extraction. The Wishart distance classification method has been used in PolsarPro software, which fits for the homogenous area. GEE can be effectively used for planning disaster risk reduction, damage assessment, affected areas, and can be used well along with cultural landscape information.

How to cite: Adhikari, R.: Mapping of Flooded Heritage Structures Using SAR Polarimetry and Google Earth Engine, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-13978, https://doi.org/10.5194/egusphere-egu21-13978, 2021.

12:10–12:12
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EGU21-15942
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ECS
William Frodella, Mikheil Elashvili, Daniele Spizzichino, Giovanni Gigli, Akaki Nadaraia, Giorgi Giorgi Kirkitadze, Luka Adikashvili, Claudio Margottini, Nikoloz Antidze, and Nicola Casagli

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.

12:12–12:14
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EGU21-16121
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ECS
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Highlight
Gulen Uncu and Eser Çaktı

Hagia Sophia is one of the most prominent architectural and structural creations in the history of mankind. Since it has been standing for the last 15 centuries, it is noteworthy to be worked on. Hagia Sophia is known to be located on eartquake zone and has high level of deformation since it has been constucted. Therefore, learning its mystery requires a great variety of analysis. Besides, instead of studying on the ideal geometry of the structure, it would be more enlightening to reveal the real deformed shape of it. An important point to be considered is using non-destructive techniques. Hence, 3D laser scanning is an effective method for this purpose. This study aimed to observe the designed and the deformed geometry of Hagia Sophia. First the structure is scanned by 3D laser scanner from both inside and outside. The point clouds obtained by each scan are combined by Cyclone software. This part of the study covers the process after the combined point cloud is meshed on 3D Reshaper software. The software allows the user to measure every detail, moreover creating ideal geometric shapes for each element is possible. In this study, the structure is first observed in detail of each structural element, then as a whole. It is seperated as primary and secondary system. In the title of primary system, first the main piers are examined, then the main arches, the main dome and dome base, tympana and the pendentives. The secondary system covered the secondary piers, secondary domes, exadrae domes, barrel vaults and the buttress piers. According to the element, the ideal geometric shapes are created like ideal vertical planes for the piers, ideal cylinders for the arches, ideal sphere for the dome etc… The comparison of the ideal geometry and the real one points the deformation. Hence, the study reveals the deformation that Hagia Sophia has undergone during the centuries.  Besides, when the ideal geometric shapes are considered as a whole, they form a consistent design. Once the shapes created seperately joined together,  they agree in the center of the structure, which supplies a satisfying verification about the study. Therefore it might give a clue about the designed geometry of Hagia Sophia. Consequently, this study will improve the structural analysis of Hagia Sophia based on more realistic data in terms of geometry.

How to cite: Uncu, G. and Çaktı, E.: Geometric Evaluation of Hagia Sophia, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-16121, https://doi.org/10.5194/egusphere-egu21-16121, 2021.

12:14–12:30