Report on LPG infrastructure impact at the WUI microscale

Preprin

Using fuzzy logic to evaluate fire vulnerability of dwellings located at the wildland-urban interface

WUI fires are posing great challenges to firefighting services, which are overwhelmed by the need to not only suppress the fire, but also protect the community. The need for self-protection is therefore growing, as is the need for the creation of fire-adapted communities. A tool that can aid homeowners and residents of the WUI is therefore created, so that they can identify the vulnerabilities present on their properties and consequently reduce them in order to diminish the risk of damage due to a wildfire. This Vulnerability Assessment Tool is based on a fault tree analysis that includes possible structural vulnerabilities as well as the different ways a fire could spread on a property to finally enter and damage the building. The identification of the probabilities of the different events in the fault tree is obtained through the use of fuzzy logic, for which inputs, outputs and rules are identified. A questionnaire targeted to homeowners and based on the fault tree and linked to the probability identified with fuzzy logic is then developed. By filling in this questionnaire, homeowners at the WUI will be able to know what the probability of a fire entering their house is. The result of the questionnaire also indicates which are the issues on the property that need to be addressed in order to lower this probability. Finally, the tool is validated with a case study of several houses affected by a fire in Spain.Postprint (published version

Evaluating wildfire vulnerability of Mediterranean dwellings using fuzzy logic applied to expert judgement

Background. Wildland–urban interface (WUI) fires pose great challenges to firefighting services and there is a growing need for self-protection and the creation of fire-adapted communities. Aim. A tool that can aid homeowners and residents of the Mediterranean WUI was created so that they can identify vulnerabilities present on their properties and consequently reduce them in order to reduce the risk of fires igniting dwellings. Methods. This Vulnerability Assessment Tool is based on a fault tree analysis that includes possible structural vulnerabilities as well as the different ways a fire could spread on a property to finally enter and ignite a dwelling. The probabilities of the different events are obtained from fuzzy preferences of WUI experts. Key results. Our system was tested against real-world data taken from two WUI fires that occurred in 2021 and 2022 in Spain in which several dwellings were affected, with different degrees of damage (minor to major losses). Conclusions. The tool is able to show the vulnerabilities of the properties and to account for differences in building characteristics and vegetation management at the parcel scale. Implications. A planned use of this tool would be key to improving fire resilience at the community level.Peer ReviewedPostprint (published version

Methodology for the analysis of structural vulnerability of WUI settlements

As WUI fires have become a global concern, there is a growing need for engineering methodologies that lead to proactive fire management not only at the landscape level, but at all WUI scales. This paper presents a quantitative methodology for structural vulnerability assessment at the WUI settlement level that is based on 10 indicators, established for the different fire exposure phases a WUI area experiences (pre-impact, impact and fire transfer) as well as on other factors that can escalate vulnerability. As output, a Structural Vulnerability Index (SVI) for the entire analyzed area can be obtained. The methodology can not only assess vulnerability of WUI settlements in a quantitative way, but it can also quantify the effect of measures employed for the reduction of this vulnerability. Additionally, the methodology is suitable for comparison between different settlements or neighborhoods of the same area. A case study for the city of Barcelona, Spain, is presented, in which 9 WUI neighborhoods are analyzed and vulnerability reduction measures are prioritized.This research is funded by the Barcelona City Council and “La Caixa” Foundation (project WUICOM-BCN, 21S09274-001), the project PID2020-114766RB-100 of MCIN/AEI/10.13039/501100011033 and the project TED2021-130484B-100, funded by MCIN/AEI/10.13039/501100011033 and the European Union “NextGenerationEU”/PRTR. The authors also want to thank Bombers de Barcelona, the Consortium of the Natural Park of Collserola for their help in data gathering and the Pau Costa Foundation. A. Águeda is a Serra-Húnter fellow.Peer ReviewedPostprint (published version

Fire performance of residential shipping containers designed with a shaft wall system

seven story building made of shipping containers is planned to be built in Barcelona, Spain. This study mainly aimed to evaluate the fire performance of one of these residential shipping containers whose walls and ceiling will have a shaft wall system installed. The default assembly consisted of three fire resistant gypsum boards for vertical panels and a mineral wool layer within the framing system. This work aimed to assess if system variants (e.g. less gypsum boards, no mineral wool layer) could still be adequate considering fire resistance purposes. To determine if steel temperatures would attain a predetermined temperature of 300-350ºC (a temperature value above which mechanical properties of steel start to change significantly) the temperature evolution within the shaft wall system and the corrugated steel profile of the container was analysed under different fire conditions. Diamonds simulator (v. 2020; Buildsoft) was used to perform the heat transfer analysis from the inside surface of the container (where the fire source was present) and within the shaft wall and the corrugated profile. To do so gas temperatures near the walls and the ceiling were required, so these temperatures were obtained from two sources: (1) The standard fire curve ISO834; (2) CFD simulations performed using the Fire Dynamics Simulator (FDS). Post-flashover fire scenarios were modelled in FDS taking into account the type of fuel present in residential buildings according to international standards. The results obtained indicate that temperatures lower than 350ºC were attained on the ribbed steel sheet under all the tested heat exposure conditions. When changing the assembly by removing the mineral wool layer, fire resistance was found to still be adequate. Therefore, under the tested conditions, the structural response of the containers would comply with fire protection standards, even in the case where insulation was reduced.Postprint (published version

Fires at the wildland-industrial interface. Is there an emerging problem?

Over the past years, wildfires have raged with unprecedented intensity across the world, becoming a growing problem, as weather conditions conductive to wildfire ignition and spread will increase in frequency and severity worldwide. This, coupled with a growing human expansion, leads to an increase in wildfire risk and in the threat to wildland-urban interface (WUI) communities. Commonly, definitions for WUI areas consider homes, commercial facilities, office and public buildings. This excludes industrial installations, where wildfires can trigger accidents or cascading events leading to extremely dangerous situations for the population causing enormous economic losses. In this paper, the problem associated to the wildland-industrial interface (WII) is analyzed. A methodology to obtain a global WII map is described, and the first WII maps for Europe and Asia are provided. Results show that, in Europe, 2.5% of the land and 6% of vegetated areas are WII, while in Asia these are respectively 0.24% and 0.5%. An analysis of how wildfire triggered industrial accidents can be considered when performing quantitative risk assessments (QRA) in industrial sites is also performed, identifying the current state of the art and research gaps, with the aim of helping industry, public authorities and policy makers, for better accident prevention, preparedness and response.This research is funded by the project PID2020-114766RB-100 of MCIN/AEI/10.13039/501100011033 and the project 2021_SGR_00251 of Generalitat de Catalunya. A. Àgueda is a Serra Hunter fellow.Peer ReviewedPostprint (published version

Vulnerability analysis to wildland- urban interface fires in metropolitan areas: an integrated approach

Wildfires pose a growing threat to populated areas around the world and especially in the Mediterranean Basin. Numerous Mediterranean cities have typically developed neighbourhoods that expand into forest land in which basic aspects for an efficient WUI fire management have not been considered. In this paper, we present a holistic approach to analyse threats to metropolitan areas due to WUI fires, accounting for infrastructural, societal and ecosystems vulnerability at settlement scale. Based on design fires and the key parameters responsible of fire impact and percolation through communities of most probable WUI fire events, we define key indicators to describe how vulnerable structures are in WUI metropolitan areas. Following, urban and societal indicators are selected to account for population’s vulnerability and, finally, ecosystems potential losses are accounted by ecosystem vulnerability indicators such as ecosystem sensitivity and adaptability. We have implemented this methodology to analyse vulnerability in Barcelona WUI areas and identified those that can be more threatened in case of wildfire. Results of this study will be key to inform risk-reduction public policies, as they provide particular insights on those WUI areas within Barcelona municipality that should be prioritized along with the specific issues that should be tackled.Peer ReviewedPostprint (published version

The Herschel-SPIRE Legacy Survey (HSLS): the scientific goals of a shallow and wide submillimeter imaging survey with SPIRE

A large sub-mm survey with Herschel will enable many exciting science opportunities, especially in an era of wide-field optical and radio surveys and high resolution cosmic microwave background experiments. The Herschel-SPIRE Legacy Survey (HSLS), will lead to imaging data over 4000 sq. degrees at 250, 350, and 500 micron. Major Goals of HSLS are: (a) produce a catalog of 2.5 to 3 million galaxies down to 26, 27 and 33 mJy (50% completeness; 5 sigma confusion noise) at 250, 350 and 500 micron, respectively, in the southern hemisphere (3000 sq. degrees) and in an equatorial strip (1000 sq. degrees), areas which have extensive multi-wavelength coverage and are easily accessible from ALMA. Two thirds of the of the sources are expected to be at z > 1, one third at z > 2 and about a 1000 at z > 5. (b) Remove point source confusion in secondary anisotropy studies with Planck and ground-based CMB data. (c) Find at least 1200 strongly lensed bright sub-mm sources leading to a 2% test of general relativity. (d) Identify 200 proto-cluster regions at z of 2 and perform an unbiased study of the environmental dependence of star formation. (e) Perform an unbiased survey for star formation and dust at high Galactic latitude and make a census of debris disks and dust around AGB stars and white dwarfs

Fire risk analysis framework at the wildland-urban interface

Tesi amb menció internacional(English) Wildfires that reach the border between the wildland and urban areas, defined as the Wildland-Urban Interface (WUI), have rapidly expanded in frequency and severity over the past few decades, and the number of structures lost each year has increased significantly. As WUI fires pose great management challenged in terms of civil protection and fire mitigation, self- protection has become a growing necessity and focus must be placed in creating fire-adapted communities that can safely co-exist with wildfires. At the WUI microscale (i.e., homeowner level), susceptibility of a home to wildfire depends on the management of its surroundings and the hardening of the structure itself. The goal of this thesis is to develop a risk analysis framework based on the analysis of the fire hazard posed by the fuels located in the surroundings of a building and on the identification of building vulnerabilities for Mediterranean WUI scenarios. To meet this goal, an analysis of the different types of fuels present on a property and of the vulnerable elements of a building is performed and three scenarios are selected for further analysis with performance-based strategies. Performance criteria are identified for each of the selected scenarios and an analysis of the available information on the fire characteristics of the different types of fuels located at the microscale is presented, which highlights a lack of quantitative knowledge on WUI fire hazards. Real-scale tests of four fuel packs that contain artificial fuels that could be present in WUI environments have therefore been performed, and the obtained results can be used for the analysis of WUI fire scenarios. A methodology for the quantitative analysis of the vulnerability of building and property sub-systems based on a Performance- Based Design (PBD) approach is presented and applied to the three selected WUI scenarios. The methodology includes the modelling of the scenarios with the Computational Fluid Dynamics tool FDS (Fire Dynamics Simulator). Results obtained from this modelling can be compared to the previously set performance criteria. When it comes to building vulnerability, a Vulnerability Assessment Tool (VAT) for Mediterranean WUI structures is developed, based on the results obtained from the sub-system scenario analysis and an extensive literature review. The tool is presented in form of a checklist and is intended to be used by homeowners, with the goal of identifying home vulnerability in a quantitative way by highlighting the main issues of a property by analysing the building and its surroundings. The application of the VAT is presented for three different case studies located in Mediterranean landscapes. Finally, a WUI specific PBD guideline is presented for the quantitative risk analysis of WUI scenarios. Within the guideline, performance criteria are presented for both life safety and property protection and suggestions on the choice of design fire scenarios for WUI environments are given, together with the different variables that should be included, such as fire, environmental and property characteristics. The methodology presented in the guideline is applied to a case study, which is modelled in FDS, based on the strategies identified for the analysis of the sub-system scenarios. The application of the methodology to the case study shows how fire safety at the WUI can be quantified and gives an example of strategies that can be implemented to reach the desired fire safety level.(Català) Els incendis forestals que arriben a la frontera entre les zones amb vegetació i les àrees urbanes, definides com la Interfície Urbana-Forestal (IUF), s'han expandit ràpidament en freqüència i severitat durant les últimes dècades, i el nombre d'estructures perdudes cada any ha augmentat significativament. Com que els incendis IUF suposen grans desafiaments a nivell de gestió en termes de protecció civil i mitigació d'incendis, l'autoprotecció s'ha convertit en una necessitat creixent i cal centrar l'atenció en la creació de comunitats adaptades al foc que puguin coexistir amb els incendis forestals de manera segura. A nivell micro-escala de la IUF (és a dir, al nivell del propietari de l’habitatge), la susceptibilitat d'una casa als incendis forestals depèn de la gestió dels seus voltants i de la resistència de l'estructura en si mateixa. L'objectiu d'aquesta tesi és desenvolupar un marc d'anàlisi de riscos basat en l'anàlisi del perill d'incendi que presenten els combustibles situats als voltants d'un edifici i en la identificació de les vulnerabilitats pròpies dels edificis per als escenaris de la IUF mediterrània. Per complir aquest objectiu, s'analitzen els diferents tipus de combustibles presents en una propietat i els elements vulnerables dels edificis, i es seleccionen tres escenaris per a una anàlisi més detallada amb estratègies basades en prestacions. Es defineixen criteris de prestacions per a cada un dels escenaris seleccionats i es presenta una anàlisi de la informació disponible sobre les característiques d'incendi dels diferents tipus de combustibles situats al micro-escala, la qual mostra que hi ha una manca de coneixement quantitatiu sobre els perills dels incendis a la IUF. Per tant, s'han realitzat proves a escala real de quatre conjunts d’elements que contenen combustibles artificials i que solen estar presents en entorns de la IUF. Els resultats obtinguts es facilitaran l'anàlisi d'escenaris d'incendi de la IUF. Es presenta i s'aplica una metodologia per a l'anàlisi quantitativa de la vulnerabilitat dels sub-sistemes d'edificis i propietats basada en l'abordatge del disseny basat en prestacions (PBD) als tres escenaris IUF seleccionats. La metodologia inclou la modelització de l'escenari amb l’eina de dinàmica de fluids computacional FDS (Fire Dynamics Simulator). Els resultats obtinguts d'aquesta modelització són comparables amb els criteris de prestacions establerts anteriorment. Pel que fa a la vulnerabilitat dels edificis, s'ha desenvolupat una Eina d'Avaluació de la Vulnerabilitat (Vulnerability Assessment Tool - VAT) per a les estructures IUF mediterrànies, basada en els resultats obtinguts de l'anàlisi dels escenaris de sub-sistemes i en una extensa revisió bibliogràfica. L'eina es presenta en forma de llista de verificació i està destinada a ser utilitzada pels propietaris de les cases, amb l'objectiu d'identificar la vulnerabilitat dels habitatges de manera quantitativa, analitzant l'edifici i el seu entorn, el que permet identificar els principals problemes de la propietat. L'aplicació de la VAT es presenta per a tres casos pràctics diferents situats en zones mediterrànies . Finalment, es presenta una guia específica per a IUF-PBD per a l'anàlisi de riscos quantitatius en escenaris IUF. Dins de la guia, es presenten criteris de prestacions per a la seguretat dels ocupants i la protecció dels béns, i s'ofereixen suggeriments sobre selecció dels escenaris d’incendi de disseny per als entorns IUF. La metodologia presentada a la guia s'aplica a un exemple pràctic, que es modela en FDS, basat en les estratègies identificades per a l'anàlisi dels escenaris de sub-sistemes. L'aplicació de la metodologia a l’exemple pràctic mostra com es pot quantificar la seguretat contra incendis a la IUF i mostra les estratègies que es poden implementar per a aconseguir el nivell desitjat de seguretat contra incendis.DOCTORAT EN ENGINYERIA DE PROCESSOS QUÍMICS (Pla 2012

WUI fire risk mitigation in Europe: A performance-based design approach at home-owner level

Fires at the Wildland-Urban Interface (WUI) are becoming increasingly hazardous for life safety and property protection. Guidelines and standards for fire practitioners are needed in order to help WUI communities face this threat and become fire-adapted. A performance-based design approach (PBD) is proposed to deal with the complex issues present at the WUI homeowner scale, which entails the use of Computational Fluid Dynamics (CFD) tools such as FDS in order to identify vulnerabilities in a quantitative manner. An analysis of recent European WUI fires is presented, along with the definition of several pattern scenarios that can be derived from these. Based on this analysis, examples of PBD fire scenarios specific for the Mediterranean WUI microscale are presented, involving glazing systems, roofing and gutters, external structures adjacent to the main building, and gaps present in the building envelope. A worked example to show the implementation of the proposed PBD method is provided in which the fire impact of residential fuel on a glazing system is quantitatively analysed.Award-winningPostprint (author's final draft