ERE1.4

ERE1 EDI
Climate change and cultural heritage: impact, vulnerability, adaptation 

Climate change is debated most often for its environmental and socioeconomic repercussions; however, it also has a dramatic impact on tangible cultural heritage worldwide. The safeguard and fruition of cultural assets – outdoors or indoors, and either on land, underground, or underwater – are jeopardized by the current and expected environmental changes. The behavior of the component materials varies likewise, in response to global warming, sea level rise, ocean acidification, and the increase of extreme weather events.
This session addresses the climate change risk to cultural heritage from the interdisciplinary perspective of geosciences, which represent a valuable support for investigating the properties and durability of the materials (e.g., stones, ceramics, mortars, pigments, glasses, and metals); their vulnerability and the changes in weathering dynamics; the key environmental variables (pertaining to climate, microclimate, air pollution, water and soil composition) and the effects of extreme events; the techniques and products to improve conservation practices; and the adaptation measures for heritage protection. This session welcomes contributions based on approaches including but not limited to field and laboratory analysis and testing; damage assessments and simulations; modelling of risk scenarios and decay trends; strategies of monitoring and remote investigation; and processing of environmental databases.

Co-organized by CL3.2
Convener: Luigi GerminarioECSECS | Co-conveners: Alessandra Bonazza, Peter Brimblecombe
Presentations
| Thu, 26 May, 15:10–17:42 (CEST)
 
Room 0.31/32

Presentations: Thu, 26 May | Room 0.31/32

Chairpersons: Luigi Germinario, Alessandra Bonazza
15:10–15:15
ENVIRONMENTAL CHANGES & MODELED RISK
15:15–15:21
|
EGU22-1776
|
ECS
|
On-site presentation
Oscar Julián Esteban Cantillo, Beatriz Menendez, and Benjamin Quesada

The analysis and interpretation of past climate data and simulations of climate models for future periods will allow us to know future climate conditions and their differences with past ones. One of the many applications of these analyzes is the study of the impacts of climate change on two types of cultural heritage that differ due to their geographical location and therefore their climatic conditions, as are vernacular cultural heritage in Europe and archaeological sites in Latin America, but they share a fundamental similarity in terms of the use of materials and construction techniques.

The first objective of our study is to review and quantify the impacts of combined climate (mean and extreme) and pollution on building materials of cultural heritage under future IPCC socioeconomic scenarios with high and low mitigation measures at years 2030, 2050 and 2070, using peer-reviewed dose-response equations.

We also focus on the degradation effects due to compound extreme events (heatwave, dry spells and extreme rainfall/flood) of each of the selected regions of our case study (European project SCORE: Sustainable COnservation and REstoration of built cultural heritage 2021-2024), in order to determine how future climatic conditions may affect the cultural heritage of some sites in Europe and Latin America. The foregoing by applying these climatic conditions in different models, based on scientific literature, that allow determining the consequences of these conditions on the materials in which these structures were built.

Finally, based on the literature review, we deliver preliminary results on a “cocktail of extreme events” experiment in laboratory specifically designed to quantify the damages and degradation of building materials due to a realistic series of adverse climate and pollution events.

How to cite: Esteban Cantillo, O. J., Menendez, B., and Quesada, B.: Climate change impact on vernacular and archaeological cultural heritage building materials in Europe and Latin America, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-1776, https://doi.org/10.5194/egusphere-egu22-1776, 2022.

15:21–15:27
|
EGU22-7880
|
Virtual presentation
Chiara Bertolin and Elena Sesana

Norway, nowadays, still preserves outstanding examples of traditional Scandinavian wooden architecture called stavkirker (i.e., stave churches), these are typical Norwegian medieval churches built since 11th-12th Centuries with posts and staves as load bearing elements. This homogeneous group of immovable cultural heritage share similar architectural features, construction materials, as well as tangible and intangible values. They represent the highly developed tradition of wooden buildings that extended at these latitudes during Middle Ages and incorporate a large reuse of decorative and construction elements originating from other stave churches built in earlier centuries. Besides having similar use and maintenance requirements still today, the stave churches have similar vulnerability, as well as risk assessment and preservation needs.

 

For their protection it becomes fundamental to analyse and predict the impact of climate change in term of expected extreme temperature and rainfall events. In fact, modification of temperature (and consequently relative humidity) and/or of precipitation amount may cause rot to the Pine wood material constituting the churches or may enhance the mechanisms of biological and mechanical decay with an ultimate loss of valuable building assets.

 

This contribution focuses on the whole group of the still existing 28 stave churches spread over 6 regions in centre-south Norway with different climate, from temperate continental climate/humid continental climate (Dfb in the Köppen classification) to cool continental subarctic climate (Dfc) passing through the Tundra climate (ET). The work introduces an overview of the churches` architectural categorization, location, and flood vulnerability; then it focuses on climate change impacts. For the analysis of temperature and precipitation extreme events the modelled grid data from the Norwegian Climate Service Center (https://nedlasting.nve.no/klimadata/kss)  over 1x1 km spatial resolution have been used. These forecasts have been produced using the regional climate model simulation COSMO-CLM1 (Consortium for small scale modelling in Climate Mode) considering the Representative Concentration Pathways RCP4.5 (i.e., slow increase of concentrations of greenhouse gases in the atmosphere until 2050 followed by emission reduction over time with, in addition, a human-induced radiative forcing at 4.5 W/m2). More than 100 Gb of data were elaborated to create a novel database with daily temporal resolution over two reference time periods i.e., the recent past (RP, 1991-2020) and the far future (FF, 2071-2100) for the location closest to each stave church. Further the analysis concentrates on extreme precipitation and temperature occurrences (e.g., > 99.99 percentile) investigated as cumulative distribution function (CDF) and complementary cumulative distribution function (CCDF). Results highlight expected anomalies in extreme events for all the 28 locations and report the total extreme precipitation and temperature related hazards as indexes which easily allow to categorize the change in risk for each stave church.

References:1Rockel, B., Will, A., & Hense, A. (2008). The regional climate model CLM. Meteorologische Zeitschrift, 17, 347–348

How to cite: Bertolin, C. and Sesana, E.: Analysis of Climate Change Impacts on the still existing 28 Norwegian Stave Churches , EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-7880, https://doi.org/10.5194/egusphere-egu22-7880, 2022.

15:27–15:33
|
EGU22-11582
|
ECS
|
Virtual presentation
Alessandro Sardella, Stefano Natali, Riccardo Cacciotti, Milos Drdácký, and Alessandra Bonazza

The risk to cultural heritage as a consequence of the impact of climate change is globally recognized, even though not exhaustively tackled with sustainable solutions and tools addressed to support policy and decision makers in the preparedness phase of risk reduction and management cycle.

This contribution aims at presenting the methodological approach applied and main results of the “Risk mapping tool for cultural heritage protection” specifically dedicated to the safeguarding of cultural heritage exposed to extreme climate changes, produced in the framework of the Interreg Central Europe STRENCH (2020 - 2022). STRENCH project is strongly based on a user-driven approach and the multidisciplinary collaboration among the scientific community, public authorities, rescue bodies and the private sector (https://www.protecht2save-wgt.eu/).

The presented tool provides hazard maps for Europe and in the Mediterranean Basin where cultural and natural heritage is exposed to heavy rain, flooding and prolonged drought. The tool enables assessing risk of cultural heritage assets based on:

  • the computation of extreme changes of precipitation and temperature performed using climate extreme indices defined by the Expert Team on Climate Change Detection Indices (ETCCDI);
  • the exploitation of the Copernicus Climate Change Service (C3S), together with Earth Observation-based data and products;
  • the integration with outputs from Regional Climate Models from the Euro-CORDEX experiment under two different scenarios (RCP4.5 and RCP8.5);
  • a developed methodology for identifying the main critical elements determining the vulnerability of cultural heritage;
  • the ranking of the vulnerability taking into account 3 main aspects, namely the susceptibility, exposure and resilience of cultural heritage.

Preliminary results from the testing of the “risk mapping tool” at European case studies (Krems-Stein in Austria and Troja-Prague in Czech Republic) allow concluding on the feasibility and applicability of the tool presented in the perspective of optimizing preparedness strategies and mitigating the risk of cultural heritage subject to climate change related actions.

In conclusion, the STRENCH project, through the implementation of its outputs, is expected to proactively target the needs and requirements of stakeholders and policymakers responsible for disaster mitigation and safeguarding of cultural heritage assets and to foster the active involvement of citizens and local communities in the decision-making process.

How to cite: Sardella, A., Natali, S., Cacciotti, R., Drdácký, M., and Bonazza, A.: A risk assessment tool for the protection of cultural heritage exposed to extreme climate events. , EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-11582, https://doi.org/10.5194/egusphere-egu22-11582, 2022.

15:33–15:39
|
EGU22-2850
|
Virtual presentation
Lola Kotova, Johanna Leissner, Matthias Winkler, Florian Antretter, Ralf Kilian, Jürgen Mossgraber, Jürgen Reuter, Tobias Hellmund, Anton Dolgov, Katharina Matheja Matheja, Michael Rohde Rhode, Uta Pollmer, and Uwe Mikolajewicz

The intensity and frequency of extreme weather events in Europe are one of the most dangerous consequences of a warming climate. Some regions suffer more under heat waves and droughts, while others are experiencing extreme rainfalls. Thus, for example, a severe flood in July 2021 in several European countries caused widespread damages particularly in Belgium and Germany.

Which extreme weather events are to be expected in the future? How can the damage of irretrievable historical sites be avoided or, at least, limited or dealt with? All these questions are addressed in the three-year research project KERES, which is funded by the German Federal Ministry of Education and Research (BMBF) and is coordinated by the Fraunhofer ISC together with the Fraunhofer EU Office in Brussels.

As first step the regional relevance of future extreme weather events in Germany will be investigated.  This information will be further used to estimate the potential damages to buildings and outdoor facilities. The precautionary and responsive measures to manage potential or acute damage situations will be investigated as well. The designed methodologies will be tested for five case studies including World Heritage Sites (historical buildings and historical gardens)  in Germany.

The major tools of KERES include building component and indoor climate simulations and high-resolution urban climate models. The necessary input will be taken from the most recent ensemble of regional climate change projections of the EURO-CORDEX Initiative (www.euro-cordex.net).  As a result, an ontology-based information system will be designed for managing the expected damage situations.

We will present first results from the KERES project. The discussion will be focused on how to access and visualize the robustness of projected changes of extreme weather events in a way oriented to individual cultural heritage sites.

How to cite: Kotova, L., Leissner, J., Winkler, M., Antretter, F., Kilian, R., Mossgraber, J., Reuter, J., Hellmund, T., Dolgov, A., Matheja, K. M., Rhode, M. R., Pollmer, U., and Mikolajewicz, U.: Making use of climate information for protecting cultural heritage from extreme weather events in a warming world, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-2850, https://doi.org/10.5194/egusphere-egu22-2850, 2022.

15:39–15:45
|
EGU22-12070
|
ECS
|
On-site presentation
Petros Choidis and Dimitrios Kraniotis

The climate of the city of Tønsberg in Norway is cold and humid. As a result, the brick-made historic buildings in this city are threatened by frost damage. Climate change is expected to affect the action of this degradation mechanism. In the current research, climate data resulting from the REMO2015 driven by the global model MPI-ESM-LR were used for periods 1960-69, 2010-2019, and 2060-69 representing the past, present, and future climate conditions. In addition, data from the ERA5 reanalysis for the present conditions, 2010-19, were used to assess the accuracy of the climate model data. Given the climate excitations, the freeze-thaw events were calculated according to two climate indices, i) the events of temperature decrease below 0oC and ii) by considering that freezing occurs below -3oC and thawing occurs above 1oC. Moreover, a material response-based index that takes into account the temperature and the moisture content of a 5mm layer in the exterior side of the wall assembly was calculated. Prior to its calculation proper hygrothermal simulations were performed. According to this index, the critical temperature and degree of saturation that characterize a freeze-thaw event are 0oC and 25%, respectively. From the climate model data and the first climate index, the 0oC crossings that were calculated are 400, 340, and 223 under the past, present, and future conditions, respectively. The respective number of the freeze-thaw events that were calculated by using the second climate index are 49, 31, and 27 which are significantly lower. From the data obtained from the ERA5 reanalysis, the number of freeze-thaw events that were calculated is 425 and 123 for the first and the second climate index, respectively. This difference is attributed to the underestimation of the air temperature in the climate model data, which results in a lower number of temperatures hovering around the examined thresholds during winter. The results of the material response-based index show a minor frost risk for the brick-made wall assemblies which is reduced through the years. The southeast-oriented walls were the ones with the highest exposure to driving rain and the greatest frost damage risk. For this orientation, the number of freeze-thaw events was 6, 3, and 2 under past, present, and future conditions, respectively. Moreover, according to the ERA5 reanalysis, only 1 freeze-thaw event was calculated. This is attributed to the fact that the climate model overestimates significantly the precipitation and the relative humidity compared to the ERA5 reanalysis. In conclusion, it is worth mentioning that both the climate-based and the material response-based indices define a decreasing trend of the frost damage risk of historic brick-made walls due to climate change. The use of the material response-based index is suggested for a more accurate assessment of the frost damage which can further support proper adaptation measures. Finally, the quality of the results can be improved by using climate data from more climate models and applying bias correction or morphing methodologies on the climate files to avoid systematic errors.

How to cite: Choidis, P. and Kraniotis, D.: Climate-based and material response-based approaches for the impact assessment of climate change on the frost damage of historic brick walls in Tønsberg, Norway., EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-12070, https://doi.org/10.5194/egusphere-egu22-12070, 2022.

15:45–15:51
|
EGU22-107
|
Virtual presentation
Elena Pérez Álvaro

Predictions forecast changes in climate that may affect cultural heritage in the future. Not only the underwater cultural heritage will become exposed, but also our land tangible cultural heritage will be submerged: entire nations and their cultural heritage may disappear, losing their identity as nations, countries, and communities. In fact, climate change has the potential to increase the sea level enough by 2100 to inundate 136 sites considered by UNESCO as cultural and historical treasures.

This presentation will examine the specific climate changes that oceans will most likely suffer and how they will probably affect tangible underwater cultural heritage, analysing how the changes will affect every possible material that can be found in a submerged archaeological site. It will also explore cases of heritage that are already suffering the consequences examining two future scenarios: how climate change may disturb underwater cultural heritage, and how land cultural heritage may change its label and subsequently become underwater cultural heritage. Lastly, the presentation will propose a new partnership natural/cultural resources and the qualification of cultural heritage as a natural resource for its preservation, establishing the same common measures for both heritage against climate change.

How to cite: Pérez Álvaro, E.: Climate change: a threat to underwater cultural heritage, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-107, https://doi.org/10.5194/egusphere-egu22-107, 2022.

ENVIRONMENTAL CHANGES & OBSERVED WEATHERING
15:51–15:57
|
EGU22-5898
|
ECS
|
On-site presentation
Luigi Germinario, Chiara Coletti, Petros Choidis, Dimitrios Kraniotis, Lara Maritan, Raffaele Sassi, Laura Tositti, and Claudio Mazzoli

This contribution presents the work of research and technical development for designing a novel method for monitoring and predicting the weathering of cultural heritage, in particular of stones and timber used historically as building materials.
An apparatus for long-term field tests was designed in its hardware and software components with a twofold application:

  • Exposure of a set of selected stone and wood specimens to natural weathering, at different orientations (North, South, and horizontal plane) and environmental settings (Italy and Norway).
  • Non-stop acquisition of microclimate data series at different resolutions, down to the scale of the specimen surface, completed by datasets of regional stations of environmental monitoring.

Complementary laboratory analyses aim at setting a reference point for the state of conservation of each material before the exposure tests, and monitoring the changes of surface recession/topography (by 3D optical profilometry), thus reconstructing the relevant deterioration trends.
Within the framework of the EU-funded project HYPERION, this novel experimental approach is expected to help assessing the interaction of building materials with the environment and their weathering constrained by microclimate and climate variability; combining climate model simulations, the stresses brought about by climate change can also be assessed. The findings might represent a source of precious information for the activities and decision-making protocols of the stakeholders involved in the protection of cultural heritage.

How to cite: Germinario, L., Coletti, C., Choidis, P., Kraniotis, D., Maritan, L., Sassi, R., Tositti, L., and Mazzoli, C.: Developing a new method for long-term monitoring of the weathering of historical building materials, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-5898, https://doi.org/10.5194/egusphere-egu22-5898, 2022.

15:57–16:03
|
EGU22-2857
|
On-site presentation
Roger-Alexandre Lefèvre, Peter Brimblecombe, and Aurélie Verney-Carron

France's monumental heritage has been the subject of little theoretical research in the face of global climate change, although many applied studies have concerned its adaptation and resilience, especially at the local level. Furthermore, this heritage includes more than 44,000 monuments and classified sites, 48 of which being inscribed on the UNESCO List and therefore deserves to be taken into account in the context of the current climate unbalance.

The complexity lies in the diversity of materials making up the monuments (stones, glass, metals, wood...) and of phenomena that affect them (as well as other constructions). In order to assess the impact of these increasing slow or extreme events already at work, the tools and methodologies range from the description and inventory of the effects, their measurement, mapping and projection into the future using models such as dose-response functions (DRF) with input data from climate models and scenarios. Ancient data can also be used to complement the correlation between climate and heritage, such as dendroclimatology studies of the wood in monuments.

Results from research carried out in France will be presented concerning stone facades, ancient stained glass windows, metals, degradation of walls by salts and dendroclimatology. Further research should focus on the consequences on the monumental heritage of rising marine waters, river and urban flood and low waters, freeze-thaw, the stability of monuments on clay soils and the indoor climate of monuments and their carbon footprint.

In conclusion, much remains to be done in France: (1) complete the inventory and description of the phenomena, their impacts and their location at the national, regional, urban and monumental scales, (2) quantify these impacts in the future via empirical or geochemical models based on climate models outputs.

How to cite: Lefèvre, R.-A., Brimblecombe, P., and Verney-Carron, A.: The French monumental heritage in the face of global climate change: state of the art and research perspectives, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-2857, https://doi.org/10.5194/egusphere-egu22-2857, 2022.

16:03–16:09
|
EGU22-12113
|
Virtual presentation
Ákos Török

Dust is one of the main pollutants that settle on historic structures and cause the blackening of stone surfaces. The stone facades of historic buildings became dark, and besides its aesthetic alteration, dust deposition and subsequent chemical reactions led to the deterioration of the construction material. The composition of dust changes in time due to climate change, clean air acts and changes in transportation, industrial activities and heat. The present study tries to detect the temporal changes in the composition of dust by using a stone buildings as dust traps in Budapest. The studied historic building is more than one hundred years old, and no façade cleaning was done in the past century. Visual inspection of the city centre building suggested that dust accumulation show a distinct pattern representing differences in the vertical profile in terms of thickness and colour. Dust samples were collected from layer to layer representing newly settled and historical dust. Scaffolds were made to reach the various elevations of the building facades. Besides the dust, host rock samples were also picked to detect textural and compositional changes of the porous oolitic limestone material. The textural-mineralogical analyses (XRD, SEM) and chemical compositional tests (XRF, LA-ICP-MS) provide evidence of changes in composition of dust with time. In all host rock samples, gypsum was detected but in various proportions. Good correlations were also found between water-soluble calcium and gypsum content and between sulphate and gypsum content both for black crusts and host rocks, forming two distinct fields in calcium vs gypsum and sulphate vs gypsum graphs. Gypsum was also found in the dust either as a primary or as a secondary mineral phase. Metals, transition metals and water-soluble ions also occur in various concentrations in different layers of dust. The detected elements primarily include  Fe, Mn, Zn, Cu, Cr, Pb, Ni. From soluble salts, chloride, nitrate and sulphate were also detected. The changes in elemental and ionic concentrations reflect temporal changes in dust composition and provide indirect evidence for air quality changes and air pollution levels.

How to cite: Török, Á.: Compositional changes of settling dust in time on buildings in Budapest: centennial evidence of air pollution trends, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-12113, https://doi.org/10.5194/egusphere-egu22-12113, 2022.

16:09–16:15
|
EGU22-2571
|
ECS
|
On-site presentation
Mathilde Ropiquet, Aurélie Verney-Carron, and Anne Chabas

Since the Industrial revolution, emissions of pollutant (gas, aerosols) due to human activities increased and modified the composition of the atmosphere, causing air pollution and climate change. However, pollution measurements are relatively recent. In order to know past air pollution and assess its impact on monuments, proxies need to be found and studied.

One of these potential local proxies is black crusts that are a chemical alteration pattern mainly found on limestone or marble monuments. They are forming a dark mineralogical layer composed of gypsum (CaSO4.2H2O) that results from the sulfation reaction between the calcite (CaCO3) of the stone and the sulphur dioxide (SO2) from the atmosphere. As gypsum is easily soluble, this pattern particularly affects sheltered area from the rain where particulate matter is trapped and accumulates. Therefore, black crusts act as passive sampler and could be used as an archive of air pollution.

To validate black crusts nomination as a new proxy and to find the best pollution marker, samples were collected at Père Lachaise cemetery on ancient tombs (dated from the 1820’s). A specific protocol was applied to separate strata from each other. Then, multiple analyses were realised using SEM-EDS, ICP-AES, and ICP-MS. The results show a different particulate content as a function of the depth, with different contributions of fly-ash typical of coal and oil combustion. This is confirmed by the chemical analyses as the trace metal concentrations are in agreement with the pollution sources. This study demonstrates that laminar black crusts have an internal stratigraphy that can be crucial to reconstruct past air pollution and provides precious data on pollution sources.

How to cite: Ropiquet, M., Verney-Carron, A., and Chabas, A.: Black crusts as past air pollution archives, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-2571, https://doi.org/10.5194/egusphere-egu22-2571, 2022.

ADAPTATION & PROTECTION
16:15–16:21
|
EGU22-5311
|
ECS
|
On-site presentation
Eda Kale, Marie De Groeve, and Tim De Kock

Historical buildings, which play a major role in shaping the urban fabric, are facing challenges due to climate change. Today the cultural values are considered among the main goals of sustainable development much like the social, economic and environmental values. Therefore it is important to discover the sustainable ways of conservation and maintenance practices on mitigating the impacts of climate change, so that the historical buildings can play an active role in achieving sustainable development goals without compromising their cultural and heritage values.

Nature-based solutions (NbS) are considered as sustainable and effective solutions on mitigating impacts of climate stressors. Exploring their compatibility to conservation practices can bring mutual opportunities to the urban fabric and to the historical buildings. However, nature has been considered as a threat amongst the conservation practices due to potential biodegradation of materials, obscuring the heritage structure and requiring an additional cost of maintenance. Nevertheless, many uses of nature-based solutions come across in history, e.g. in the form of turf or sod roofs that provide thermal insulation on extreme climate conditions. Today, there are some attempts to integrate NbS to heritage environments within the scope of retrofitting projects. Nevertheless, a comprehensive methodology of performance assessment on mitigating climate challenges without compromising the cultural and heritage values has not been developed yet.

This project aims to develop a decision making framework for heritage actors on evaluating the compatibility of NbS to conservation and maintenance practices of historical buildings that are exposed to adverse impacts of climate stressors in the urban context. For developing a general outline of the framework, various NbS will be evaluated and categorized based on quantitative data in the literature according to their aesthetic fit to historic buildings, their structural feasibility and their performance on mitigating the effects of climate stressors. Throughout the project, process and value based research will be conducted on carefully selected case studies. The selected case studies will be evaluated within the scope of determining the severity of the prevailing climate stressors in their context, their structural sensitivity and their adaptability capacity to the new interventions. Based on the results, the compatible NbS and design measures can be identified. In the later stages of the project, the feasibility of the proposed nature-based design for the case studies will be tested by monitoring and comparing the results before and after the implementation.

How to cite: Kale, E., De Groeve, M., and De Kock, T.: Developing a Decision Making Tool for Evaluating the Compatibility of Nature-Based Solutions to the Built Heritage, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-5311, https://doi.org/10.5194/egusphere-egu22-5311, 2022.

16:21–16:27
|
EGU22-3476
|
Virtual presentation
Maria Krommyda, Nikos Mitro, Katerina Georgiou, Vassillis Nousis, and Angelos Amditis

Climate change has been proved to have negative impacts on historic areas hosting cultural heritage sites and monuments, which in turn yields significant adverse impacts on local economies, societies, and even politics. The first and necessary step of the process of confrontation of this challenge is the early detection and recording of the on-site inflicted damage by a monitoring tool. In order to achieve that, we developed a dedicated mobile application that aims to assist the assessment of the resilience and the deterioration of the historic areas and the potential impacts due to various hazards. Citizens and local authorities worldwide can directly use the developed application on their mobile phones to acquire photos of on-site damages and submit short reports based on them. This software component has been designed and developed in the context of the European project entitled “HYPERION”, which aims to deliver an integrated resilience assessment platform, addressing multi-hazard risk understanding, faster and efficient response, and sustainable reconstruction of historic areas.

With this application, we aim to create a user-friendly application with the latest user interface and usability issues/trends which is focused on museum enthusiasts and active citizens’ or travelers’ needs. It’s important to put the users of this targeted group at the center of our efforts and by understanding their needs to create an intuitive application for them and at the same time a useful tool for the local authorities.

Users download the application from the Google or Apple App store and they log in or create an account in the application through the PLUGGY platform, which was developed in the context of the “PLUGGY” European project. The main function of the application is to create and post an asset using PLUGGY’s REST API. An Asset is an elementary unit of content in PLUGGY, a media file with an identified owner, a title, a description, a set of tags, and a license, which specifies how this file can be reused. Initially, the user’s location is detected via GPS and corrected in case of miscalculation. The user is then prompted to select a photo (or directly to take a snapshot) that depicts the damage of a monument. To complete the creation of the asset, the user will also need to select a title that will accompany the photo, and some tags, not only for a better description of the event but also for correlation with other assets or exhibition points that already exist in PLUGGY.

The developed mobile application gives voice to citizens and encourages them to provide direct feedback to the relevant cultural authorities, in order to assist them in assessing the deterioration of the cultural heritage sites and determining the needed reconstruction actions. As a result, the communities can have a major role in the safeguard of their cultural heritage.

How to cite: Krommyda, M., Mitro, N., Georgiou, K., Nousis, V., and Amditis, A.: A Communities Engagement Mobile Application for Assessing the Resilience and Deterioration of Cultural Heritage Monuments, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-3476, https://doi.org/10.5194/egusphere-egu22-3476, 2022.

Coffee break
Chairpersons: Luigi Germinario, Alessandra Bonazza, Ákos Török
17:00–17:06
|
EGU22-5264
|
On-site presentation
Scott Allan Orr, Sebastiaan Godts, and Tim De Kock

Salt weathering is a complex and active area of research, with implications for tangible cultural heritage worldwide. A preventive conservation approach is often taken to limit salt crystallisation cycles, which requires an understanding of the relative risks of scenarios and their respective heritage characteristics, salts present, and the climate, including climate change. Equilibrium relative humidity is an important property that indicates this risk: typically, it is represented by specific RH% and temperature derived from a single salt. The behaviour of single salts does not accurately represent the behaviour of salt mixtures, which are far more common in cultural heritage contexts. To address this, 11412 salt mixtures present in the built environment have been analysed using the ECOS/Runsalt model to predict their mixture-based mutual relative humidity of crystallisation and deliquescence points, the salt mixture composition, as well as the relative humidity of crystallisation and deliquescence for individual salts in the mixtures. This dataset, although sampled primarily from Belgian cultural heritage sites, is representative of the general classes of salt mixtures found in the built environment globally. This analysis represents an important step in developing a generalised statistical method for parameterising environmental time series data for salt weathering risk within climate change scenarios, as well as progressing fundamental knowledge on the behaviour of salt mixtures in built cultural heritage.

How to cite: Orr, S. A., Godts, S., and De Kock, T.: A data-driven approach to understanding the equilibria behaviour of salt mixtures in built cultural heritage, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-5264, https://doi.org/10.5194/egusphere-egu22-5264, 2022.

17:06–17:12
|
EGU22-7085
|
ECS
|
On-site presentation
Marie De Groeve, Eda Kale, Scott Allan Orr, and Tim De Kock

Due to hard coverage and building infrastructures, cities experience higher temperatures and higher pollution levels in their city centre relative to their less dense surroundings. This urban heat island effect is receiving an increasing amount of attention and concern. In response, cities are implementing green initiatives to mitigate elevated temperature and pollution levels, improving the health and well-being of their residents. However, the urban heat island is typically the largest in the historical core of the city, where the abundance of built heritage can make the implementation of green initiatives difficult. The dense urban fabric and the rules of conservation make such an implementation inconvenient. A major concern is how green initiatives might affect the condition of the historical building materials.

Therefore we scope the compatibility of vertical greening with built heritage, in terms of microclimatic changes, and considering impacts of salt crystallization, frost events, biodeterioration and pollutant deposition. The vertical greening represents vegetation growing along exterior walls. Either plants, rooted on the ground, climb up the facade by attaching themselves on the vertical surfaces or plants hang down from the top of the facade. Monitoring case studies in Antwerp and laboratory studies will help us investigate key changes, beneficial or adverse, in the material condition of heritage buildings. This project will develop our understanding of the relationship between the green initiatives and the historical materials in an urban area.

How to cite: De Groeve, M., Kale, E., Orr, S. A., and De Kock, T.: The effect of vertical urban greening on historical building materials, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-7085, https://doi.org/10.5194/egusphere-egu22-7085, 2022.

MATERIAL PROPERTIES & DURABILITY
17:12–17:18
|
EGU22-10024
|
Virtual presentation
Oliver Sass and Heather Viles

Water plays a vital role in the deterioration and conservation of built heritage and management problems might be aggravated by climate change. However, there is as yet no overarching framework for understanding the processes and impacts of water interacting with building materials. The term 'Heritage Hydrology' is a holistic way of conceptualising the flows and stores of water involved in deterioration of built and rock-hewn heritage. We distinguish the following basic types: (a) stone-built buildings, (b) ruins and free-standing walls, and (c) rock-hewn sites which include carved rock art and large rock sculptures. We focus on a key knowledge gap: The spatial and temporal characteristics of water flows/stores and the challenges of using currently available techniques to provide information on these characteristics.

In our selective review we provide examples of spatio-temporal patterns of moisture in stonework at different scales. We raise six key points about the state of research on heritage hydrology, from which we develop a future research agenda. (1) Three characteristics of moisture regimes are important to deterioration, i.e. presence, fluctuations and saturation thresholds. (2) There is a wide range of different heritage hydrological settings ranging from masonry building walls to natural rock slopes, and as yet no clear understanding of the commonalities vs specificities of these different settings. (3) While there is now a wide array of techniques available to measure and monitor moisture regimes in lab and field settings, the understanding of how comparable different measurement approaches are is still lacking. (4) There are now many measurements of the spatial patterning of moisture, but lack of clarity about the causes of these patterns. (5) There has been less research focusing on the temporal dynamics of moisture on heritage walls than on spatial patterns. (6) Studies combining measurement and modelling have proved particularly useful.

A research agenda for the future for heritage hydrology should focus on addressing the following broad questions: What are the best combinations of methods available to measure and model spatio-temporal patterns in moisture on built and rock-hewn heritage? What are the major factors controlling spatio-temporal patterns in moisture, also considering climatic changes? Which spatio-temporal patterns in moisture are most important for driving deterioration, and how do their respective scales interact? Tackling these research questions requires a coordinated approach, linking different research teams and methodologies. It should be based on a combination of data collected through laboratory experiments, detailed studies of test walls, and instrumented sections of walls at heritage sites. It should explore the causes and consequences of moisture regimes which provide fundamental links between climate and the deterioration of built and rock-hewn heritage.

How to cite: Sass, O. and Viles, H.: Heritage hydrology: A conceptual framework for understanding water fluxes and storage in built and rock-hewn heritage , EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-10024, https://doi.org/10.5194/egusphere-egu22-10024, 2022.

17:18–17:24
|
EGU22-8814
|
ECS
|
On-site presentation
Tomáš Weiss and Oliver Sass

Weathering is a key component of the geomorphological process system and poses a major threat to cultural heritage, such as building structures and rock art sites. Since almost all rock decay is enhanced by the presence of water, research on moisture content and flow is crucial to understanding weathering processes. Nevertheless, measuring rock moisture and its fluctuations is difficult as there is no universally used sensor that meets the requirements of non-destructiveness, reliability, repeatability, and applicability at field sites. Therefore, this work aims to evaluate several moisture measurement techniques under different natural conditions and to provide recommendations for their use. We tested seven types of methods (1D resistivity, 2D resistivity, TDR, borehole humidity, microwave reflectance, IR thermography, and uranine probes) under controlled conditions in a sandstone block that was subject to a slow wetting and drying cycle and to a series of freeze-thaw cycles.

Overall, the methods measuring dielectric properties of the rock (TDR, microwave) can be generally recommended for their reliability, repeatability, and applicability at field sites. Precise observation of moisture dynamics in deeper subsurface however remains a challenge, especially when moisture contents are close to drier states. Therefore, to get reliable water content data, it is vital to drill inside the rock rather than to use surface sensors, which are particularly sensitive to surface moisture and surface roughness. Nonetheless, out of the non-destructive surface methods, dielectric sensors using the microwave spectrum with a greater penetration depth (>10 cm) should be considered as they have the advantage of interacting the transmitted signal into a larger volume of material, therefore making the influence of surface less pronounced. Furthermore, the use of electrical resistance methods is less recommended because of mainly two factors: they need to be calibrated for each sensor pair, and they are prone to erroneous measurements in the presence of salts. Concerning the other methods, probes using a reactive dye, and borehole humidity sensors can be used to determine the location of the subsurface evaporation front where salt crystallisation takes place, and the IR imaging for studying evaporation dynamics needs either highly controlled environment or continuous measurement. In conclusion, this work provides new insights into rock moisture measurements and further research should focus on subsurface moisture measurements and the improvement and calibration of available techniques.

How to cite: Weiss, T. and Sass, O.: The challenge of measuring rock moisture: A laboratory experiment using eight types of sensors, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-8814, https://doi.org/10.5194/egusphere-egu22-8814, 2022.

17:24–17:30
|
EGU22-5806
|
Presentation form not yet defined
Chiaki Oguchi and Yukina Ikeda

Tuff is rich in color and is used as a stone material, and it is also a rock that forms a unique landscape in Japan, a volcanic country. However, since it is generally a fragile rock, it is susceptible to weathering and deterioration. The present study conducted an experiment to confirm the effectiveness of the surface protectant using tuff with different physical characteristics. Sodium sulfate aqueous solution was used to determine the effectiveness of protective agent application for 5 types of tuff (Oya stone, Nikka stone, Ashino stone, Tatsuyama stone, Towada stone) An experiment was conducted in which the lower 3 cm of a 5 cm × 5 cm × 15 cm specimen that had been oven-dried at 110 ° C was immersed in a salt solution, and 20 ° C-40 ° C was repeated for up to 20 cycles in a 48-hour cycle. When the weight and P-wave velocity of each specimen were measured every cycle, the solution reached the surface of the uncoated stone material for comparison, salt crystals were deposited. The surface of the specimen was peeled off, and the P-wave velocity gradually decreased.  On the other hand, in the stone material coated with the protective agent, salt crystallization was not observed even when the solution reached the top surface shortly after the start of the experiment.  The P wave velocity did not decrease, despite cracks occurred as the experiment progressed. As a result, the P-wave velocity began to decrease and the surface layer fell off. In Ashino and Tatsuyama stones, the coated specimens were more severely destroyed than the uncoated specimens. In Oya stone and Towada stone, which contain clay minerals (miso) in the form of patches, crushing proceeded from the miso part. This experiment suggests that the effect of the protective agent may depend on the rock structure and the pore diameter. In other words, for rocks containing miso, the use of a protective agent is likely to increase deterioration regardless of the pore structure. For rocks with a large proportion of micropores and low durability against salt weathering, the use of a protective agent is used. Therefore, the start time of surface exfoliation can be delayed. In addition, in rocks with a large proportion of large gaps (> 10-0.5 μm), even if crystallization occurs on the surface of the specimen. The  peeling does not occur for a while, but the protective agent penetrates deep into the thick protective agent penetration area. It is considered that the crystallization of the salt occurs more internally and the deterioration is more severe than it should be. 

How to cite: Oguchi, C. and Ikeda, Y.: Influence of rock pore structure on the protective coating against weathering, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-5806, https://doi.org/10.5194/egusphere-egu22-5806, 2022.

17:30–17:36
|
EGU22-8670
|
Virtual presentation
David Martin Freire-Lista, Rebeca Blanco-Rotea, Maria do Rosário Costa, and Jorge Sanjurjo-Sánchez

This study aims to characterise the decay due to black patinas of Santalla de Bóveda Monument (Lugo, Northwest of Galicia, Spain).

Manganese is one of the most abundant elements on Earth, and the granite on which Santalla de Bóveda Monument was built (used as building material of the monument) has considerable amounts of Manganese. This monument shows black patinas on the surface of its building materials (mortars and granites).

Mortars and granite with Mn-rich black patinas were analysed in their chemical, mineralogical and petrographical properties (polarizing and scanning electron microscopes, X-ray diffraction and X-ray fluorescence). In addition, the water from springs near the monument was analysed.

According to the experimental study results, it was observed that rich Mn-oxide crusts are presumably induced by bacteria. That is, the oxidation of Mn fuels the growth of chemolithoautotrophic microorganisms, which need water to live. These patinas of biogenic Mn-oxide minerals presented different shapes, nano-dimensions, with low degree of crystallinity, and appear to be composed of manganese oxides such as birnessite, ramsdellite and groutellite. They were associated with large amounts of extracellular polymeric substances exuded by filamentous bacterial communities, which serve as nuclei for preferential precipitation of manganese oxides on the extracellular sheaths, as seen in scanning electron microscope analyses.

Mn required for patina formation likely derives from the reductive dissolution in water of Mn-rich minerals, as suggested by the mineralogy and chemistry of Mn-rich phases present in the building granite and mortars. Mn migrates to the exposed surface of building materials, where they are re-oxidized via biological processes. Patinas developing over time result from the alternation of wetting-reducing and drying-oxidizing cycles.

Water absorption, dampness and black patinas are among the most common and critical problems when it comes to decay of both cultural heritage and modern buildings. The climate and specifically the humidity are determinant for the development of Mn-rich black patinas. Results revealed that chemical composition and porosity played a major role in the development of biological activity that generates the black patinas of manganese oxides on mortars and granite.

How to cite: Freire-Lista, D. M., Blanco-Rotea, R., Costa, M. D. R., and Sanjurjo-Sánchez, J.: Mn-rich Black Patina Formation on Built Heritage in Humid Areas, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-8670, https://doi.org/10.5194/egusphere-egu22-8670, 2022.

17:36–17:42
|
EGU22-5301
|
ECS
|
On-site presentation
Laurenz Schröer, Tim De Kock, Sebastiaan Godts, Nico Boon, and Veerle Cnudde

During the 21st Century, climate change and improving air quality will alter biological communities and their influence on building stones. While air pollution used to be a principal factor of stone deterioration, it is diminishing in many parts of the world. These environmental changes affect the aesthetics of building stones, and fewer black gypsum crusts will form, while more biological-induced discolorations could occur. Within the British Isles, it resulted in the “greening” of monuments after increased algal growth. Besides aesthetical damage, the formation of biofilms could affect water transport and retention. Changes in the water-stone relationship should be studied in detail because moisture is the most significant facilitator of stone alteration, leading to physical, chemical and further biological weathering.

This topic was intensely studied on soils. However, knowledge of the effect of biofilms on water transport and retention of stones is limited. For this reason, three porous natural building stones: Ernzen, Euville and Savonnières, were biofouled at the outer surface with the cyanobacteria Phormidium autumnale. The colonization was estimated by spectrophotometry, and their relationship with the stones was studied by Scanning Electron Microscopy (SEM), Environmental SEM (ESEM) and optical microscopy on thin sections. Based on the European standards, the water transport properties were determined of biofouled and untreated samples.

Microscopy showed that the biofilms covered the surface while they spanned over and closed numerous pores. They had a measurable effect on water transport and retention and reduced the rate of capillary water absorption and drying in combination with higher moisture content after (vapor) sorption. Moreover, the biofilms changed the surface wettability and induced near hydrophobic conditions in a dry state while no effect was measured on the water vapor diffusion and air permeability. These changes can alter the material properties and other processes like salt weathering and freeze-thaw damage. As swelling and shrinkage were observed by ESEM, the properties and physical effects of biofilms are expected to change with fluctuating relative humidity.

How to cite: Schröer, L., De Kock, T., Godts, S., Boon, N., and Cnudde, V.: The influence of biofouling on water transport inside porous stones, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-5301, https://doi.org/10.5194/egusphere-egu22-5301, 2022.