NH9.10 | Natural hazards’ impact on natural and built heritage and infrastructure in urban and rural zones
EDI

The session welcomes papers dealing with disaster impact on architecture, landscape, urban and cross-border areas, territory, natural (protected) areas and infrastructure, including but not limited to:
- Digital photographic or 3D models reflecting pre-disaster state of affected areas, for example before and after disaster, before and after reconstruction surveys
- Decision methods to balance between the (landscape)architecture/artistic/historic value and vulnerability in order to select appropriate preventive retrofit or post-disaster repair methods
- Ways to consider regional characteristics when selecting the prevention measures or when rebuilding after disaster
- Local culture in vernacular architecture based on historic disaster experience
- Illustration of historic disasters in image and photography
- Post-disaster planning interventions (restructuring/reconstruction/reconfiguration/revitalization/ renaturation/restoration, etc.), which led to the positive/negative transformation of a landscape, an urban area or an architectural (heritage) construction
- Mapping techniques of landmarks perception for consideration in reconstruction after disaster
- Cultural Landscape elements associated genius loci - the memory of a place/architectural construction/urban area/landscape/territory, that went through a disaster or that developed as a result of post-disaster planning operations
- Nature based solutions for disaster resilience, including climate change effects
- Urban wildland interface for the forest and natural protected areas in the city, urban water interface by adapting in practice the solutions based on resilient planning in relevant cases
- Ecosystem-based fire risk reduction and adaptation in practice
- Solutions to minimize risk in areas with major infrastructure and utility networks, through design and urban planning
- Impact assessment on infrastructure systems with a particular interest in flooding on transportation network.
- Any other related topics.

Public information:

Special issue in Natural Hazards and Earth System Sciences open for submission

https://www.natural-hazards-and-earth-system-sciences.net/articles_and_preprints/scheduled_sis.html#1252

Convener: Maria Bostenaru Dan | Co-conveners: Adrian IbricECSECS, Margherita D AyalaECSECS, Orsolya Kegyes-Brassai, Mara PopescuECSECS
Orals
| Thu, 27 Apr, 14:00–15:45 (CEST)
 
Room 1.34
Posters on site
| Attendance Thu, 27 Apr, 08:30–10:15 (CEST)
 
Hall X4
Posters virtual
| Attendance Thu, 27 Apr, 08:30–10:15 (CEST)
 
vHall NH
Orals |
Thu, 14:00
Thu, 08:30
Thu, 08:30

Special issue in Natural Hazards and Earth System Sciences open for submission

https://www.natural-hazards-and-earth-system-sciences.net/articles_and_preprints/scheduled_sis.html#1252

Orals: Thu, 27 Apr | Room 1.34

Chairperson: Margherita D Ayala
14:00–14:05
14:05–14:35
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EGU23-11418
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NH9.10
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ECS
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solicited
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Highlight
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On-site presentation
Enrico Pigazzi, Riccardo Bersezio, Federica Marotta, Cristiana Achille, and Tiziana Apuani

Natural disasters, such as postglacial landslides in Alpine valleys, recurrently reshape the natural and human landscape, impacting on settlements, land-use and architecture. Historical catastrophes were sometimes narrated and painted, so that in these cases chronicles and artistic representations can be integrated to geological, geomorphological, geophysical and archaeological data to describe the co-evolution of the natural and cultural landscape. This is the case of the Piuro landslide that in 1618 almost completely buried this renown and rich trading town in the Bregaglia Valley (Italy), on the way to the relevant alpine Maloja pass. Since it totally modified the valley floor, the catastrophe represents a turning point that permits to i) attempt the 3D reconstruction of the natural and archaeological landscape before and immediately after the disaster, ii) unravel the post-1618 increments of evolution of the natural landscape and settlements, iii) retrieve the memory of the area that underwent the disaster. To accomplish these aims we integrated: a new detailed DTM; a reconstruction of the relative chronology of burial, erosion and stabilization of the landforms after natural and anthropic processes pre- and post-dating the 1618 landslide; some subsurface stratigraphic logs and images based on new boreholes and geophysical surveys; age determinations based on radiocarbon and archeological/historical data; chronicles and paintings depicting the Piuro area before and after the disaster. The images we could draw show how human settlements were continuously controlled by the occurrence of landslides and other catastrophic processes like debris flows, before and after the 1618 landscape turning point. In the valley center we could detect a pre-1618 landslide body, whose mega-boulder reliefs were settled at least since the 4th – 5th century AD, at present buried below the Middle-ages and Renaissance Piuro villages. These landslide bodies provided also favorable settings for food preservation, whose memory and usage survived and reached the present-day under the vernacular denomination of “crotti”. At the millennial time scale no stable geomorphological surfaces do exist on the valley floor and lower slopes, since we could map the chronology of building of the debris flow-fan lobes, demonstrating how they evolved before and after the 1618 landslide, burying and/or being buried by the two major landslide bodies and interfingering with the trunk river alluvial sediments. Radiocarbon age determinations, archeological findings and the known ages of historical buildings permitted to recognize the geomorphological surfaces that remained stable on a shorter, secular, time scale, where the settlements could resume still competing with catastrophic processes that led to repetitive burial of several buildings during the last three centuries. Based on these results we could draw the 3D models of the Piuro area predating and immediately postdating the 1618 catastrophe. Historical paintings and chronicles largely confirm the relative chronology of landscape changes that we propose.

The present work was co-funded through the EU, Regional Development European Fund, by Italian State, Helvetic Confederation and Cantons under the Interreg V-A IT-CH 2014-2020 Cooperation Program - A.M.AL.PI.2018 “Alpi in Movimento, Movimento nelle Alpi. Piuro 1618-2018", ID 594274 – Axis 2 “Cultural and natural enhancement”.

How to cite: Pigazzi, E., Bersezio, R., Marotta, F., Achille, C., and Apuani, T.: Impact of historical landslides on natural landscape and human settlements in the core of the Alps: the Piuro 1618 disaster in the Bregaglia Valley., EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-11418, https://doi.org/10.5194/egusphere-egu23-11418, 2023.

14:35–14:45
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EGU23-806
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NH9.10
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ECS
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On-site presentation
Paulo Cabrita, Enrico Duo, Juan Montes Pérez, Riccardo Brunetta, and Paolo Ciavola

Extreme events can cause damage to coastal defences resulting in overtopping, breaching, or their total destruction. The resulting flood can impact the population and assets, causing short- to long-term losses to the economy. Two examples of extreme coastal storms are the Katrina Hurricane (2005) in the USA, and the Xynthia storm (2010), in France. The Northern Adriatic Sea is often impacted by coastal storms, impacting residential and commercial areas. The region of Emilia-Romagna (Italy) is so often affected that it is common practice to create an artificial dune on the beach during winter to protect the properties.
On 22 November 2022, a coastal storm developed in the Northern Adriatic Sea, impacting the coasts of Veneto and Emilia-Romagna Italian regions. This storm, coming from ESE, was characterised by non-extreme waves, but coincided with spring tides, producing an extreme surge, reaching a total water level of 1.48 m above MSL, recorded for the first time by tide gauge at Porto Garibaldi (Comacchio), which corresponds to a return period greater than 100 years. The Saint Agatha storm that hit the same areas in 2015, reached a TWL of 1.2 m at the same location. The event of November 2022, caused damages on the coast, erosion of beaches, artificial and natural dunes, damage to coastal infrastructures, and flooding of residential buildings and local business activities. 
While this storm represented a success for the MOSE, which succeeded in protecting the lagoon of Venice against one of the most hazardous events of the last decades, its effects on the Ferrara coasts were, in some cases, devastating. The most affected area was the Lido di Volano (Comacchio), where the extreme event caused a dike breach in the inner part of the Po di Volano mouth, leading to the recurring flooding of the town, due to the high spring tides that followed the storm. Indeed, the breach remained open for several days after the event. The event required the heavy involvement of first responders.
The site was surveyed on 23 and 25 November 2022. The research team measured flood extension and flood markers with the use of DGPS and aerial images, while UAV aerial surveys were implemented on the emerged beach to assess the morphologic impacts.
The flood associated with the extreme event was simulated using a hydrodynamic model (LISFLOOD-FP) to verify the causes and evolution of the flood event. The model was set up using topo-bathymetric data from 2019, water levels from the tide gauge of Porto Garibaldi.  A thorough calibration was implemented using the fieldwork data. The model was used to simulate scenarios considering different dike-breach configurations and/or forcing it with other recent events (e.g. Saint Agatha, 2015). 
The model was able to properly simulate the flooding event of November 2022. The tested scenarios highlighted the role of the magnitude of the event and the effects that a breaching dike can have on the associated areas. This is a contribution to the ECFAS project (EU H2020 GA 101004211).

How to cite: Cabrita, P., Duo, E., Montes Pérez, J., Brunetta, R., and Ciavola, P.: Coastal flood pathways driven by extreme storm surge and dike failure in the Northern Adriatic, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-806, https://doi.org/10.5194/egusphere-egu23-806, 2023.

14:45–14:55
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EGU23-12737
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NH9.10
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ECS
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On-site presentation
Amalia Gutierrez, Marc-Henri Derron, Li Fei, Christian Gerber, and Michel Jaboyedoff

The effects of climate change on ageing infrastructures, due to temperature variations, insolation, and especially increased runoff due to extreme precipitations, are not insignificant. In addition,  expected changes in land use and increased impact of anthropic activity, as well as  the degradation of infrastructures due to age, will potentially impact the utility lifespan of a great variety of works. Whether it be retention walls for vineyards, near roads or next to railroad tracks, it is important to determine to what extent climate change and anthropic activity will accentuate the hazard of failure of protective or retaining infrastructures and their backfills. Especially when these are located along busy routes (pedestrian, automobile, railroad, etc.) and can potentially impact moving objects (for example trains with passengers). Even though these events are not so rare, and  the damages caused are easily repaired or managed, their global costs and impacts are very seldom quantified. In order to gain a better overview on the global cost of these types of events and the associated impacts, in particular in areas where maintenance is not so frequent, an inventory of events for the Western Alpine Switzerland was carried out. The associated costs were ascertained either in prevention and maintenance work or in emergency measures and reparation. Examples of events having a significant impact, include those of La Conversion (2021), Châtillens Ecublens-Rue (2013), Col de la Croix (2021), L’Etivaz (2018), La Forclaz (2018, 2022), Col des Mosses (2015), route d'Oron (2014, 2021), Ollon (2021), and Belmont-sur-Lausanne (2021); which were studied in more detail. Information on these events were gathered from various sources including newspaper articles, official reports, and interviews with witnesses and experts. And the conditions leading to such events, such as antecedent precipitation, age of the structure and structural condition, were investigated and analyzed. The results of the analysis were then used to identify a few sites susceptible to this kind rupture in the future, via reports, aerial images, and fieldwork, and subsequently mapped and communicated to the corresponding authorities.

How to cite: Gutierrez, A., Derron, M.-H., Fei, L., Gerber, C., and Jaboyedoff, M.: What is the real impact of instabilities and ageing infrastructure along roads and railways ? Analysis of an event inventory in the Western Alps, Switzerland, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-12737, https://doi.org/10.5194/egusphere-egu23-12737, 2023.

14:55–15:05
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EGU23-3275
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NH9.10
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On-site presentation
Quantitative disaster risk assessment for railway:challenges and a promising solution based on BIM+GIS
(withdrawn)
Yiming Cao, Hengxing Lan, and Langping Li
15:05–15:10
15:10–15:20
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EGU23-468
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NH9.10
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ECS
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On-site presentation
Nurullah Bektaş, Kevin Karanja Kuria, and Orsolya Kegyes-Brassai

One of the critical research areas of engineering science is the assessment of existing buildings' seismic vulnerability. Since the existing building stock is made up of structures that were built before design codes were developed, taking into account low or moderate design codes may make them vulnerable to an upcoming earthquake. To this end, rapid visual screening (RVS) methods can be used to identify building vulnerability before or after an earthquake. A number of RVS methods have been developed; however, it's critical to assess their accuracy in terms of their ability to reliably classify the state of building vulnerability. Therefore, this study offers an application of conventional RVS methods (FEMA P-154, RISK-UE Project, JBDPA), as well as a comparison of the results of the building safety level classification of 20 existing reinforced concrete buildings from Győr, Hungary. Pushover analysis was used as a detailed vulnerability assessment technique in addition to the RVS methods to evaluate one more reinforced concrete building. The findings of pushover analysis and RVS methods are contrasted to demonstrate how effectively RVS methods can be utilized to determine building vulnerability. Additionally, the findings of this study can be used to select an RVS method for commencing a pre-earthquake building assessment of the existing reinforced concrete building stock in the investigation area.

Keywords: earthquake; existing buildings; vulnerability assessment; rapid visual screening; machine learning; building damage state

How to cite: Bektaş, N., Kuria, K. K., and Kegyes-Brassai, O.: A comparative vulnerability assessment of reinforced concrete buildings using rapid visual screening methods and pushover analysis, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-468, https://doi.org/10.5194/egusphere-egu23-468, 2023.

15:20–15:30
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EGU23-1805
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NH9.10
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Highlight
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On-site presentation
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Chi-Tung Hung, Wen-Yen Lin, and Shao-Hsien Lu

The past literatures regarding hazard risk cases and theories generally lack of risk-oriented spatial planning and dialogue, which induce so called “weakness policy” phenomena. The research contents and objectives of this study are to construct an all-hazards river basin governance index system under the impact of COVID-19 pandemic as the mean of research methodology, and applying AHP and GIS overlays as the analysis tools, to assess the disaster social-economic vulnerability and mitigation response on the case study site of Da-an river basin townships in central Taiwan. This study has found: 1) the noise and environmental pollutions caused by religion activities has decreased owing to the pandemic impact; 2) the Central Government’s "Stimulus Voucher" policy and tourists’ “retaliatory consumption” are benefiting local tourism industry under the pandemic.

How to cite: Hung, C.-T., Lin, W.-Y., and Lu, S.-H.: The All-Hazards River Basin Governance Risk Assessment Strategy Under Covid-19 Pandemic Impact: A Social-Economic Vulnerability Case Study of Da-an River Basin Area in Central Taiwan, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-1805, https://doi.org/10.5194/egusphere-egu23-1805, 2023.

15:30–15:40
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EGU23-3726
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NH9.10
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On-site presentation
Assessment the Influence of Social Capital on the Promotion of Resilient Community and preservation of Cultural Heritages in Taiwan
(withdrawn)
Kuo-Chen Ma and Mo-Hsiung Chuang
15:40–15:45

Posters on site: Thu, 27 Apr, 08:30–10:15 | Hall X4

Chairperson: Nurullah Bektaş
Earthquakes
X4.77
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EGU23-16953
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NH9.10
Orsolya Kegyes-Brassai and Md Faiz Shah

Being part of the expert team sent by Hungarian National Directorate General for Disaster Management to Tirana after the 6.4 magnitude earthquake in 2019, and experienced the fear of residents living in slightly or heavily cracked buildings raised the question of preparedness to against seismic events in other moderate seismic regions such as Hungary. Recent earthquakes within the moderate range have proved that moderate seismicity does not necessarily equate to moderate damage suffered.

Vulnerability to earthquakes has increased due to extending urban areas. This paper presents lessons learnt after medium-sized earthquakes and examines the adaptability of measures taken afterwards and the possibility to apply these methods to other regions in Hungary and throughout Europe where the seismic hazard is not great, but cannot be ignored. To reduce the potential damage, a comprehensive assessment of the seismic risk followed by a package of relevant remedial measures is needed. Methods developed for Hungary is presented compared to methods applied in other regions to determine local site effects, vulnerability, and preparedness, being the main components responsible to risks. Based on the results, engineers can better plan to make improvements to infrastructure, and authorities can better plan for emergency activities in case of a seismic event.

How to cite: Kegyes-Brassai, O. and Shah, M. F.: Adaptability of lessons learnt from recent medium-sized earthquakes to moderate seismic zones – disaster management perspectives for unprepared societies, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-16953, https://doi.org/10.5194/egusphere-egu23-16953, 2023.

Floods
X4.78
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EGU23-11862
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NH9.10
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ECS
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Margherita D Ayala, Marcello Arosio, and Mario Martina

Flooding constitutes the most frequent and one of the most destructive natural disasters, and every year it affects millions of people worldwide causing loss of life, disruption of many essential services. Even in Italy, floods represent one of the most widespread extreme events, increasingly common and hazardous.

Due to the big discrepancy, highlighted in an Italian recent report, between funds spent before and after the occurrence of a flood event, respectively for risk prevention and for recovery, it is of major interest understanding where money is spent both from a geographical perspective and from a risk level area point of view.

Through a deep analysis on the economic and technical criteria used to design infrastructures for flood risk protection, based on the Italian ReNDiS database (Repertorio Nazionale degli interventi per la Difesa del Suolo – National Database of soil protection measures) a comparison between type of hydraulic infrastructures and their cost, and official risk maps produced in accordance with the EU flood Directive (2007/60/EC) have been done.

Moreover, this work also aims to understand if the current criteria with which flood risk maps are produced catch the effects in terms of benefit of the flood risk mitigation measures.

The authors want to prove the importance of a risk-based design for mitigation measures instead of a simple application of the current legislation that does not catch all the components of the risk.

How to cite: D Ayala, M., Arosio, M., and Martina, M.: A comparison between investment in hydraulic infrastructures and the consequent risk reduction: a case study in Italy, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-11862, https://doi.org/10.5194/egusphere-egu23-11862, 2023.

X4.79
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EGU23-11765
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NH9.10
Meng-Hsuan Wu and Wei-Cheng Lo

The causes of inundation in urban areas were numerous and complex. Even though there were flood mitigation facilities, once the rainfall intensity and the downstream tidal level were exceedingly high, the flood in drainage could not be drained in time or even overflow. Detention pond was an important flood mitigation facility in recent years. However, the detention efficiency might be affected by the timing of the operation. The harmful runoff that cannot be drained caused flooding in the urban areas. In order to avoid the problem of flooding in the local area caused by the superposition of runoff, it was necessary to analyze the surface runoff of the urban areas caused by the storm events on the basis of the current flood mitigation facilities.

The establishment of the PHD model was carried out to test the calculus of Typhoon Nesat in 2017, extremely heavy rainfall events 0823 in 2018 and 0813 in 2019 as a verification case. The water level between the simulated and measured results of the typhoon and rainfall events was compared. These results shows a good agreement in the peak value of water level, and the PHD model can reasonably calculate the runoff.

Analyze the optimal conditions of the detention facilities. Based on two consecutive 10-year heavy rain events (with an interval of 12 hours), and start pumping at different delays, calculate the water depth to analyze the flood reduction effect of the detention facilities. Analysis of the flood reduction effect based on the average reduction of water depth, the results show that when the pumping is started about 4 hours after the flood peak, the effect of lowering the water level of the detention pond can be better.

How to cite: Wu, M.-H. and Lo, W.-C.: Application of Urban Inundation Model in Flood Mitigation of Detention Pond, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-11765, https://doi.org/10.5194/egusphere-egu23-11765, 2023.

Stormsurge
X4.80
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EGU23-2184
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NH9.10
Hee Jung Ham, Sungsu Lee, and Ho-Jeong Kim

Investigations of flow separation regions on building roof surfaces in turbulent wind flows are important because of the large aerodynamic loads that the flows cause (Fig. 1). The extreme pressure occurred in separation bubbles makes roof components of buildings vulnerable (Fig. 2).

          

Various methods have been applied to determine the mean size of roof separation bubbles by evaluating the reattachment length through wind tunnel experiments. Among them, the mean reattachment length evaluated using Particle Image Velocimetry shows high accuracy (Fang and Tachie, 2019). However, there are limits to the method of estimating the mean reattachment length only with the measured pressure data without flow measurement. Recently, a methodology for estimating mean reattachment length using a database of previously evaluated pressure coefficients and mean reattachment lengths has been proposed (Akon, 2017). However, with this method, it is difficult to evaluate the mean reattachment length for cases with different geometries of building model or flow characteristics that are not in the database.
 
The Proper Orthogonal Decomposition (POD) can decompose physical fields according to the variables they affect. If the variables decomposed by the POD have physical meanings, separation and reattachment phenomena occurring on the roof can be identified using these variables. 

In this study, the eigenmode of the roof pressure measured in the wind tunnel experiment is identified using the POD, and based on this, the mean reattachment length of roof-separation bubbles is evaluated (Figs. 3 and 4). The POD results are also validated by comparing mean reattachment lengths evaluated using the POD and aerodynamic database.

               

In the case of the roof centreline, it can be seen that the mean reattachment length based on the POD is in good agreement with that using the aerodynamic database with a difference of within 5%. It can be concluded that the application of the POD proposed in this study is useful when the mean reattachment length needs to be evaluated using pressure data.

ACKNOWLEGEMENTS
This research was supported by a grant (RS-2022-00155691) of Disaster-Safety Industry Technology Commercialization R&D Program, funded by Ministry of Interior and Safety (MOIS, Korea).

REFERENCES 
1.  Akon, F. A., 2017. Effects of turbulence on the separating-reattaching flow above surface-mounted, three-dimensional bluff bodies. Ph.D. Dissertation, Western University.
2. Fang, X. and Tachie, M. F., 2019. Flows over surface-mounted bluff bodies with different spanwise widths submerged in a deep turbulent boundary layer. Journal of Fluid Mechanics 877, 717-758.
3. Simiu, E., 2011. Design of Buildings for wind: a guide for ASCE 7–10 standard users and designers of special structures. Wiley.
4. Stevenson, S. A., Kopp, G. A., and El Ansary, A. M., 2018. Framing failures in wood-frame hip roofs under extreme wind loads. Front. Built Environ.

How to cite: Ham, H. J., Lee, S., and Kim, H.-J.: Determination of Mean Reattachment Length for Roof-Separation Bubbles using Proper Orthogonal Decomposition, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-2184, https://doi.org/10.5194/egusphere-egu23-2184, 2023.

Volcanoes
X4.81
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EGU23-6926
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NH9.10
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ECS
Ana Miranda-Hardisson, Luis González de Vallejo, José A. Rodríguez-Losada, Luis Hernández-Gutiérrez, Ernaud de Villepreux, Aarón Álvarez-Hernández, Germán Cervigón-Tomico, Héctor de los Ríos Díaz, David Afonso-Falcón, and Nemesio M. Pérez

Between September and December 2021, a Strombolian fissure eruption with phreatomagmatic pulses occurred in the Westside of the Island of La Palma (Canary Islands, Spain), giving rise to a volcanic edifice called Tajogaite and whose cone reached a height of 1121 m. above sea level (200 m above the pre-eruption topography) with a volume of 34 Mm3 consisting of the alignment of 6 different craters of 557 meters in length, direction N130ºE.

In order to analyze the stability of the volcanic edifice and estimate the possible risk of lahars from pyroclastic materials lying on the slopes of the volcano and the surrounding areas, a series of investigations have been carried out consisting on historical series of rainfall data, thickness estimation  of the ashes deposits, laboratory tests on in situ samples, density, friction angle and cohesion of the soils determinations, as well as a geophysical survey using MASW seismic technique geotechnical properties of the slope layers in the first 30 meters of the volcano slopes. Based on these investigations, a stability analysis of the slopes of the volcanic edifice has been carried out considering different rainfall scenarios. Slope stability calculations were carried out using the Slide V6 program, from geotechnical data obtained in laboratory and from limit equilibrium back analysis conditions. Two main scenarios were analyzed including the most probable and the least probable rainfall, corresponding to the return period of  10 years and 50 years respectably.

Risk of lahars had been indentify as possible for the 50 years return period, as a consequence of both the instability of the cone slopes and the surrounding ash deposits, associated with very intense rains. These data has been incorporated to the land planning of reconstruction development, particularly the adoption of preventive measures in case of intense rainfall, as well as for the design of drainage infrastructures.

How to cite: Miranda-Hardisson, A., González de Vallejo, L., Rodríguez-Losada, J. A., Hernández-Gutiérrez, L., de Villepreux, E., Álvarez-Hernández, A., Cervigón-Tomico, G., de los Ríos Díaz, H., Afonso-Falcón, D., and Pérez, N. M.: Stability analysis of the Tajogaite volcano slopes and lahar hazards for reconstruction and land planning in the affected areas, La Palma, Canary Islands, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-6926, https://doi.org/10.5194/egusphere-egu23-6926, 2023.

X4.82
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EGU23-7752
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NH9.10
Cooling rates and thermal-geomechanical properties of the lava flows of Tajogaite eruption (La Palma, Canary Islands) for land use planning and infrastructures reconstruction.
(withdrawn)
Luis González de Vallejo, Ana Miranda-Hardisson, Aarón Álvarez-Hernández, José A. Rodríguez-Losada, Pedro A. Hernández, Luis E. Hernández-Gutiérrez, Germán Cervigón-Tomico, Ernaud Villepreux, Héctor de los Ríos Díaz, David Afonso-Falcón, Antonio J. Álvarez Díaz, and Nemesio M. Pérez
X4.83
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EGU23-13809
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NH9.10
Jose Antonio Rodríguez-Losada, Luis E. Hernández-Gutiérrez, Ana Miranda-Hardisson, Luis I. González de Vallejo, Germán Cervigón-Tomico, Héctor de los Ríos Díaz, Ernaud de Villepreux, Aarón Álvarez-Hernández, and David Afonso-Falcón

The Tajogaite volcanic eruption took place at the west side of La Palma (Canary Archipelago) from september 19 to december 13 of 2021. Around 200 million cubic meters of lava emitted by the volcano ended up burying an area of 12.2 km2, destroying around 1,700 buildings and causing the displacement of roughly 7,000 people. In order to promote the recovery of the affected territory, the regional authorities commissioned to the Volcanological Institute of the Canary Islands (INVOLCAN), a report consisting on a Evaluation of the slopes stability in the new lava field and nearby areas which is summarized in this work. The results were applied to a three selected areas called reconstruction sectors with the following names: 1) La Laguna, 2) La Asomada and 3) Las Norias-La Majada. These sectors were divided into 250 x 250 m grids on which a susceptibility estimation was carried out.

The field reconnaissance and aerial photography, allowed the identification of a series of surfaces and slopes within those sectors whose stability was valued based on the Slope Susceptibility Index in Volcanic Terrains (ISTV). The stability was scaled into four main categories according to the ISTV value: very high (ISTV ≥80); high (ISTV 60-79); moderate (ISTV 35-59) and low (ISTV <35).

In La Laguna sector, of four study points, two of them were classified as moderate, one as low and another one as high. In La Asomada sector, only one study point could have been evaluated as high and finally, in Las Norias-La Majada sector, of twelve study points, eight of them were classified as moderate, two as low, one as high and another one as very high, being the moderate ISTV the most dominant in this sector.

How to cite: Rodríguez-Losada, J. A., Hernández-Gutiérrez, L. E., Miranda-Hardisson, A., González de Vallejo, L. I., Cervigón-Tomico, G., de los Ríos Díaz, H., de Villepreux, E., Álvarez-Hernández, A., and Afonso-Falcón, D.: Evaluation of the slopes stability in the lava field of the 2021 Tajogaite eruption (La Palma, Canary Islands) in order to recover the territory for the development of new infrastructures, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-13809, https://doi.org/10.5194/egusphere-egu23-13809, 2023.

Multihazard
X4.84
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EGU23-745
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NH9.10
Saad AlHumidan

AlUla, is a city in the Medina Region in north-western Saudi Arabia. The city lies within the governorate of Ula, one of seven in the Medina Region, covering an area of 29,261 square kilometres. The city is 110 km southwest of Tayma and 300 km north of Medina. The city (municipality) covers 2,391 square kilometres. The population of the city is 5,426.

The walled city of AlUla was founded in the 6th century BC.It was located along "Incense Road", the network of routes that facilitated the trading luxury items through Arabia, Egypt and India. AlUla stands on the site of the Biblical city of Dedan but was founded with the ancient North Arabian Kingdom of Lihyan, which ruled from the 5th to 2nd century BC. The older history of the oasis has been divided into several phases. The Dedanite kingdom spans the seventh and sixth centuries BC. It is thought that around the turn of the fifth century BC the kingdom became hereditary. In the 20th century the new town centre was established beside the old town and eventually the people left the old buildings. The last family left in 1983. Both the ruins of the town and the site of the Liyhanite settlement now lie within the limits of the modern town. AlUla has the potential to be one of the most important archaeological destinations for tourists from around the world. AlUla’s Hegra archaeological site (Al-Hijr / Mada’in Salih) was the first world heritage property to be inscribed in Saudi Arabia. A major integrated archaeological survey of AlUla valley and beyond was launched by the royal commission for AlUla (RCU). AlUla is a unique and extraordinary landscape because of the distinct geological eras packed together in one region. The earliest of the geologic ages which formed the rocks during the Precambrian Arabian shield rocks, marked by different layers of sedimentary rock. Second, the area’s underlying sandstone created during the Cambrian period and tectonic activity has helped further shape its dramatic geology, creating volcanic landscapes, basalt plateaus and sandstone massifs. These geological features enable the area to act as a water catchment basin allowing the valley to flow southwards towards AlUla’s settlements. Trilobite trace fossils discovered in sandstone date to at least 252 million years ago. The soft and porous rock, perfect for carving, also acts as an aquifer that can store the vital fresh water resources required to sustain life in an arid environment. Following that the black basalt layer formed by volcanic eruptions creates the dramatic plateaus called the Harrat. The desert of AlUla is famous for its several geological rock formations, formed over millions of years by wind and water, to form natural shapes untouched by human hands. geological and geophysical studies show that Geohazards in the area may include weathering and erosion processes, rock falling or sliding, and collapse of the carved architectonic structures.

How to cite: AlHumidan, S.: Geo-Hazardous of AlUla Ancient City, Saudi Arabia, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-745, https://doi.org/10.5194/egusphere-egu23-745, 2023.

Posters virtual: Thu, 27 Apr, 08:30–10:15 | vHall NH

Chairperson: Maria Bostenaru Dan
vNH.6
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EGU23-6703
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NH9.10
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ECS
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Maria Bostenaru Dan, Adrian Ibric, and Mara Popescu

Following the current digital transition pillar of societal transformation, there is an opportunity in using new technological developments and large-scaling up of digitization instruments in the field of heritage assessment. Such tools may include digital humanities methods of image annotation and mapping, architectural volumetric analysis and collecting and analyzing heritage databases. At the same time, urban and landscape heritage is also facing increasing threats from climate changes and there is immediate need of built heritage protection from natural hazards. In this context, from a higher education institutional point of view, it is advisable to align both the tertiary education curriculum and the strategic research activity in order to increase and adapt the expertise of future graduates, of the academic community, teachers and researchers.

In 2021, revisions for strategic research pillars were conducted at the University of Architecture and Urban Planning in Bucharest. As part of this revision process, five draft strategic framework documents were developed, as final results of short research projects that received funding through either internal or national grant competitions. These constitute the basis for formulating and updating the research policies of the university, for the 2021-2027 timeframe. Of the five documents, two analyze research in the field of the protection of built heritage and research dealing with protection of general built environment from disasters - investigating national, european and international policies, the institutional expertise and human capital, and also the funding potential for future projects. 
In 2022, new projects in these fields were awarded grants and started to be implemented, including one of fundamental research about which this presentation will be. The project proposes to transform the collection of photographs of early 20th century architecture (Art Nouveau and Modernism across Europe), into a database by answering the research question on how threats from the hazards of earthquake, flood and fire can be answered taking into account the local culture in the European countries covered. Answering this research question will help defining criteria which underpin decisions in order to prioritise the retrofit interventions depending on the geographic positions of the buildings, at different scales, from the neighbourhood to the region. In particular the project looks at the Mediterranean region for Modernism, as the simple vernacular shapes inspired this current and at the national romantic and similar styles at the time of the so-called Art Nouveau in particular in Eastern Europe. Areas with buildings of these styles experienced at least historic earthquakes and it will be investigated in how far the national "other Modernisms" and Art Nouveau variations were adapted to this or not by following the local seismic culture. Further research will investigate the same for flood and fire. For this purpose digital humanities methods of image annotation (including architectural volumetric analysis) and mapping are employed. The subject is innovative as only recently the role of humanities in the fields of history and art history started to deal with the subject of catastrophes, following social sciences which entered this field of engineering and natural sciences, including in this session block.

How to cite: Bostenaru Dan, M., Ibric, A., and Popescu, M.: Strategic decisions for retrofit of heritage buildings in different geographic areas of Europe, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-6703, https://doi.org/10.5194/egusphere-egu23-6703, 2023.

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EGU23-3953
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NH9.10
Luis Hernández-Gutiérrez, José A. Rodríguez-Losada, Ana Miranda-Hardisson, Luis González de Vallejo, Germán Cervigón-Tomico, Héctor de los Ríos Díaz, Ernaud de Villepreux, Aarón Álvarez-Hernández, and David Afonso-Falcón

The eruption of the Tajogaite volcano occurred between September and December 2021 in the westside of the island of La Palma (Canary Islands) buried an area of 12,19  km2, and destroyed about 1700 buildings. The need of recovering the territory, led the regional authorities to commission a work to the Volcanological Institute of the Canary Islands (INVOLCAN), consisting on the elaboration of a geotechnical map with a classification for the aptitude of the terrain in terms of bearing capacity of buildings foundations and other structures, summarized in this work. The results were applied to 3 pre-selected areas called reconstruction sectors: La Laguna, La Asomada and Las Norias-La Majada. These sectors were divided into 250 x 250 m grids on which the classification was carried out.

From the field reconnaissance, and the support of photogrammetric tools, 5 geotechnical units were identified with similar geomechanical and geotechnical behavior: Unit 1, very scoriaceous "aa" lava flows with channels and levees of moderate unevenness; Unit 2, very scoriaceous "aa" lava flows with channels and levees of steep slopes; Unit 3, "pahoehoe" surfaces with cracks and cavities; Unit 4, pyroclastic cone of the Tajogaite volcano and proximal ash deposits; Unit 5, Scattered and distal ash deposits of the main cone. Based on the geomechanical quality of the materials, they were classified into four categories according to the value of the RMR index (Rock Mass Ratio): bad (RMR 0-25); moderate (RMR 26-50); good (RMR 51-75); very good (RMR 76-100).

Within the La Laguna sector, of the 19 grids analyzed, 17 were classified as "moderate" and 2 as “good”. In the La Asomada sector, 6 grids that compose it were classified as “moderate” and in Las Norias-La Majada sector, made up of 17 grids, 15 of them were classified as “moderate” and 2 as “bad”.

How to cite: Hernández-Gutiérrez, L., Rodríguez-Losada, J. A., Miranda-Hardisson, A., González de Vallejo, L., Cervigón-Tomico, G., de los Ríos Díaz, H., de Villepreux, E., Álvarez-Hernández, A., and Afonso-Falcón, D.: Geotechnical zoning of the new lava field of 2021 Tajogaite volcano (La Palma, Canary Islands) and its application in the recovery of the territory for new urbanization, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-3953, https://doi.org/10.5194/egusphere-egu23-3953, 2023.