The Relationship between Intangible Cultural Heritage and Urban Resilience: A Systematic Literature Review

: The need to study and understand urban resilience has been defended by academics, justiﬁed by a new global context characterized by a growing urban population and a changing climate. Moreover, the importance of intangible cultural heritage (ICH) has been recognized by UNESCO since 2003. Nevertheless, the relationship between ICH and urban resilience discourses is recent, with academic studies on this topic seeing an exponential growth from 2017 onward. This article aims to develop a systematic literature review in order to answer the research question “how does intangible heritage relate to urban resilience?” and present current academic debates on this relationship. Following a methodology which entailed an academic database search and the application of exclusion criteria, 94 results from Scopus and Web of Science were retrieved and analysed. The article presents a discussion of results and showcases an existing linkage between both areas of study. This study demonstrates the fragmentation and diversity of the debates when addressing the relationship between the two topics, with an existing focus on sustainability discourses, built heritage and the role of local communities. Moreover, the article also shows a prevalence of discourses based on an engineering resilience approach. Considerations for future approaches to ICH and urban resilience are presented, namely, the need to better integrate ICH into urban resilience discourses. City, Culture and Society; International Archives of Photogrammetry, Remote Sensing and Spatial


Introduction
The aim of this article is to investigate and understand the relation between intangible cultural heritage (ICH) and urban resilience in the academic literature, while recognizing the role that such factors, both intangible heritage and urban resilience, presently have on contemporary issues that affect urban spaces, such as the threat of climate change. Existing literature reviews on urban resilience have so far focused on a theoretical discussion surrounding the definition of resilience, or the role of urban resilience in the face of climate change and sustainable approaches to cities; however, there is not yet a publication that has systematically reviewed the academic journal database across all disciplines to provide a comprehensive landscape of the relationship between urban resilience and ICH.
In order to attempt to fill this gap, this article performs a systematic literature review which crosses the topics of intangible heritage and urban resilience. By focusing on the research question "how does intangible heritage relate to urban resilience?" this review aims to unveil the main debates surrounding the topics at hand. Trends and possible gaps are identified, contributing to the development of future scientific related studies, which place intangible heritage at the centre of urban resilience discourses.
This systematic literature review was consolidated through the study of similar methodologies [1], comprising the definition of three stages: data collection (comprising the search strategy rationale and the definition of inclusion and exclusion criteria); bibliometric analysis (quantitative characterization and categorization of results); and qualitative analysis (assessment and comparison of results).

Urban Resilience
The need to study and understand urban resilience has been defended by academics, justified by a new global context characterized by a growing urbanization and a changing climate. Much of the world's population now live in urban spaces, and the needs and risks that these areas are facing today must be addressed [13,14]. Resilience has also been adopted to urban planning because cities have been theorized as highly complex and adaptive systems, despite urban resilience being regarded as a controversial concept [15]. Nevertheless, and despite being increasingly used in science and policy circles, it is still a term that does not have a universally accepted definition [16][17][18].
In recent years there has been a number of studies which have discussed the meaning of resilience and its application to different fields. In fact, there is considerable variation in the ways in which resilience is understood, investigated and applied by the literature. According to [16], there has been a great deal of revisions to the concept of resilience and its meaning, applications, and functions, with a constant concern for response to change in several fields such as natural conservation, disaster management, climate change adaptation, human development, and urban planning. In addition, resilience discourses have evolved from a perspective centred on an objective analysis to a more integrated and holistic understanding of how subjective understandings of risk, and the socially differentiated experience of disasters, relate to social vulnerability and to intervention and support [16]. On the other hand, [14,18] refer to urban resilience as the ability of an urban system-and all its networks across temporal and spatial scales-to maintain or quickly return to desired functions in the face of a disturbance, but also to adapt to change, and transform systems that limit current or future adaptive capacity [14,18].
The academic literature has mainly explored three main approaches to resilience, referred by [19] as persistence, adaptation, and transformation. The first type of resilience, engineering resilience, is measured in terms of recovery-the sooner the functionality of a system is restored after being threatened by disturbances, the more resilient that system is. This interpretation is linked to the assumption that a system has a single steady state or equilibrium to which it must return, and thus, the engineering resilience approach emphasises the ability and speed a system adopts to bounce back to its original condition after a disturbance [20]. A second definition, socio-ecological resilience, expands the meaning of resilience by putting the emphasis not so much on resistance and how long it takes for the system to bounce back, but on adaptability and how much disturbance the system can take and stay within critical thresholds [21][22][23]. The qualitative difference between these two interpretations is that, whilst engineering resilience considers only one equilibrium and thus merely emphasises the persistence of its state-meaning the ability to remain stable within this single equilibrium-socio-ecological resilience recognises that a system can have multiple stable states, which may evolve and change, providing the system remains functional, and therefore values both persistence and adaptability [20].
The third type of resilience, according to [22], is evolutionary resilience, which challenges the whole idea of equilibrium and is based on an understanding of the world as chaotic and inherently unpredictable. The author suggests that the very nature of systems may change over time with or without external shocks. Evolutionary resilience expands the other two types of resilience to incorporate the dynamic interplay of persistence, adaptability and transformability across multiple scales and timeframes [22]. This perspective is also addressed by [24], who argues that, in the face of the different approaches to the concept of resilience, it is important to see resilience as a process likely to change over time, a fruit of the adaptative nature it must embrace in order to become efficient. Therefore, it cannot be a stagnated term or approach if it is to be successful. The resilience of a system depends on the context of the evolution of that system, which is non-linear and self-organizing [22]. This perspective urges urban planners to focus not so much on order and certainty, but on connectivity and contingency and on seeking opportunities out of crises [22].
According to [23], resilience implementation in cities usually follows an engineered and simplistic perspective framed around security and protection in the face of change, guaranteeing business continuity and socio-economic status quo. Such an approach has been embraced by policymakers since it does not threaten power structures. Nevertheless, [14] highlights the fact that a more transformative perspective of resilience has been integrated in most of the current definitions of urban resilience from academics and through policy implementation frameworks. Furthermore, and according to [25,26], in order to better integrate resilience discourses with sustainable discourses, urban planning needs to adopt new paradigms of both sustainability and resilience to further transform cities.

Methodology
To answer the research questions of this paper, a systematic literature review (SLR) is applied, with the aim of ensuring high-quality results, maximizing objectivity, and allowing the research to be duplicated. The SLR aims at mapping and evaluating the main literature to identify research gaps and present the limits of knowledge of the subject area. SLR differs from a traditional narrative review by adopting a systematic process that can be reproduced, in a scientific and transparent way, minimizing bias through exhaustive bibliographic searches of studies, and providing concrete steps for decision control [27]. A flowchart of the systematic literature process can be seen in Figure 1.
needs to adopt new paradigms of both sustainability and resilience to further transform cities.

Methodology
To answer the research questions of this paper, a systematic literature review (SLR) is applied, with the aim of ensuring high-quality results, maximizing objectivity, and allowing the research to be duplicated. The SLR aims at mapping and evaluating the main literature to identify research gaps and present the limits of knowledge of the subject area. SLR differs from a traditional narrative review by adopting a systematic process that can be reproduced, in a scientific and transparent way, minimizing bias through exhaustive bibliographic searches of studies, and providing concrete steps for decision control [27]. A flowchart of the systematic literature process can be seen in Figure 1. The search strategy entails an academic database search, blind to impact factor, on two search engines: Web of Science (WoS) and Scopus, with the aim of collecting studies which investigate the relationship between urban resilience and intangible heritage. Scopus was selected as it is the most extensive scientific literature database, covering studies from social sciences that are more relevant to urban issues [28,29]. Scopus focuses particularly on journals, rather than on other forms of scientific publication [30]. This specificity is in line with the authors' intention of avoiding literature review across reports and conference proceedings, which often have not been subjected to a rigorous peer-blind review process [30]. Additionally, the Web of Science complements the research with higher ranking journals.
The search was conducted throughout March 2021. Table 1 presents the keyword combinations used for each database, along with the total results gathered without limitation in any capacity besides the exclusion of duplicates. Excluding the duplicates, a total of 206 results were retrieved, with many papers found addressing rural heritage The search strategy entails an academic database search, blind to impact factor, on two search engines: Web of Science (WoS) and Scopus, with the aim of collecting studies which investigate the relationship between urban resilience and intangible heritage. Scopus was selected as it is the most extensive scientific literature database, covering studies from social sciences that are more relevant to urban issues [28,29]. Scopus focuses particularly on journals, rather than on other forms of scientific publication [30]. This specificity is in line with the authors' intention of avoiding literature review across reports and conference proceedings, which often have not been subjected to a rigorous peer-blind review process [30]. Additionally, the Web of Science complements the research with higher ranking journals.
The search was conducted throughout March 2021. Table 1 presents the keyword combinations used for each database, along with the total results gathered without limitation in any capacity besides the exclusion of duplicates. Excluding the duplicates, a total of 206 results were retrieved, with many papers found addressing rural heritage instead of urban heritage. Also, a significant number of other papers regarding resilience were related to climate change and sustainability issues, leaving aside the heritage topic.

Research Expressions
"Cult* Heritage" Cit* Urb* Resilien* "Immaterial Cult* Heritage" Cit* Urb* Resilien* "Immaterial Heritage" Urb* Cit* Resilien* "Intangible Heritage" Urb* Cit* Resilien* "Intangible Cult* Heritage" Cit* Urb* Resilien* Total Results: 206 The asterisk is used on the research as an wildcard symbol that broadens the search by finding similar words that start with the same letters on the search engines.
For this research it was used to retrieve variations of the terms culture, city and resilience. The second step of the methodology is to apply exclusion criteria to the gathered results. Four criteria were adopted as listed in Table 2, in order to limit the number of results. The first criterion concerns the availability of results to the institution (University of Porto); the second criterion concerns results published in English; the third criterion relates to the suitability of results in relation to the research question-this means that the selection of results pertaining to this criterion was accomplished by the content analysis of titles, abstracts and keywords of the gathered results in order to verify the relation between urban spaces and heritage. Whenever this relation was not clear, the full text was analysed. Lastly, the fourth criterion pertained to the inclusion of results which were peer-reviewed, whether these were articles, published books or book sections. This criterion served to ensure that only results which guaranteed their scientific validation were considered. After the application of these selection processes, a total of 94 results were retrieved for further analysis. Table 2. Quantification of data.

Inclusion and Exclusion Criteria Number of Results
Availability to the institution 164 Results published in English 139 Suitability of results to research question 120 Inclusion of peer-reviewed results 94 Table 2 summarizes and quantifies the data retrieved through the search strategy rationale previously described, providing an overview of the main results obtained in each step, which lead to the final sample.
Following the gathering of results, their analysis ensued. This analysis was made using a mixed-methods approach. This approach entails a bibliometric analysis that allows for a quantitative vision of the gathered results, as well as a qualitative analysis made through VosViewer software (version 1.6.16) and a content analysis.

Bibliometric Analysis
The second step of the systematic literature review is to make a bibliometric analysis of the 94 results, which allows for a quantitative characterization and categorization of results. The quantitative data analysis enables the study of scientific attributes of the publications' fixed parameters through an objective approach. With that in mind the following data was extracted and analysed: type of work; source; author(s); co-authorship; and year of publication.
Concerning the type of work, journal articles are the most present, with 76 results out of 94. These are followed by book sections, with 16, and books, with only 3. Regarding the sources of this publications, the results are very scattered. In fact, the majority of the journals don't have more than one associated publication. The exceptions to this are: Looking at the gathered results, most of the authors appear associated with only one publication. The exceptions to this are Katia Fabbricatti [31,32]; Antonia Gravagnuolo [15,33]; Alessandra Gandini and Leire Garmendia [34,35], whose names appear associated to two publications each in co-authorship with other authors. A co-authorship analysis of the authors with the greatest number of connections can be seen in Figure 2. This analysis corresponds to a single article [36] with the highest number of authors, in a total of thirteen authors. This network was created by using the VosViewer software. Concerning the type of work, journal articles are the most present, with 76 results out of 94. These are followed by book sections, with 16, and books, with only 3. Regarding the sources of this publications, the results are very scattered. In fact, the majority of the journals don't have more than one associated publication. The exceptions to this are: City, Culture and Society; International Archives of Photogrammetry, Remote Sensing and Spatial Information Sciences; Land Use Policy (2 results each); Historic Environment: Policy and Practice (3 results) and Journal of Cultural Heritage Management (4 results). With 12 results, Sustainability is the most prominent journal regarding the research topic.
Looking at the gathered results, most of the authors appear associated with only one publication. The exceptions to this are Katia Fabbricatti [31,32]; Antonia Gravagnuolo [15; 33]; Alessandra Gandini and Leire Garmendia [34,35], whose names appear associated to two publications each in co-authorship with other authors. A co-authorship analysis of the authors with the greatest number of connections can be seen in Figure 2. This analysis corresponds to a single article [36] with the highest number of authors, in a total of thirteen authors. This network was created by using the VosViewer software. Concerning the timeline of publications, the year with most published works is 2020, with 23 associated publications, followed by 2019, with 22. These are, by far, the two years with most publications. The gathered results date back to the year 2008 with only one associated publication. The years between 2008 to 2021 were taken as a time period, as the first publication focusing on "cultural heritage" dates from 2008, though its focus is on the relationship between cultural heritage vulnerability and seismic prone regions. This can be seen in Figure 3.
As is also shown in Figure 3, the year 2017 was when the publications concerning the topics of urban resilience and intangible heritage started to grow. This could be explained by an equally growing interest in recent times on the topic of resilience by academics alike, concerning the most diverse areas of knowledge. Concerning the timeline of publications, the year with most published works is 2020, with 23 associated publications, followed by 2019, with 22. These are, by far, the two years with most publications. The gathered results date back to the year 2008 with only one associated publication. The years between 2008 to 2021 were taken as a time period, as the first publication focusing on "cultural heritage" dates from 2008, though its focus is on the relationship between cultural heritage vulnerability and seismic prone regions. This can be seen in Figure 3.
As is also shown in Figure 3, the year 2017 was when the publications concerning the topics of urban resilience and intangible heritage started to grow. This could be explained by an equally growing interest in recent times on the topic of resilience by academics alike, concerning the most diverse areas of knowledge.
Furthermore, the graphic also demonstrates the growing trend of publications concerning the theme under analysis. All gathered results were published well after 2003, the year of the publication of UNESCO's 2003 Convention for the Safeguarding of the Intangible Cultural Heritage, which demonstrates that, despite intangible heritage being recognized as an important asset by key institutions such as UNESCO, it took almost two full decades for academic debates and research concerning its relationship with resilience discourses to catch up.  Furthermore, the graphic also demonstrates the growing trend of publications concerning the theme under analysis. All gathered results were published well after 2003, the year of the publication of UNESCO's 2003 Convention for the Safeguarding of the Intangible Cultural Heritage, which demonstrates that, despite intangible heritage being recognized as an important asset by key institutions such as UNESCO, it took almost two full decades for academic debates and research concerning its relationship with resilience discourses to catch up.

Qualitative Analysis
A qualitative analysis of the gathered results was employed in order to identify the clusters most related with the research question and the most recurring in the retrieved publications. This was achieved using VosViewer software and a content-based analysis.

VosViewer Analysis
VOSviewer provides a visualization of the relatedness between different text-based items-each corresponding to one publication-to better understand the relationships between the gathered results. The software achieves this purpose by grouping the different terms into clusters, allowing for a more efficient analysis. These clusters are assembled using the qualitative method of content-based qualification and are selected in line with the publications' keywords and main topics. Therefore, clusters are assembled by systematically inventorying and bundling each publication's keywords, abstracts and main topics. The closer two items are to each other according to an automated analysis of their text, the stronger their relatedness and, thus, the greater visual weight of each item [37], providing a visual representation of the weight of each semantic group, as well as the links between them. Figure 4 provides this analysis, from which three visual groups were formed (red, green and blue) based on interconnected content. Looking at the terms associated with each group, we can see that the thematic surrounding heritage-which is the most prevalent concept and plays a central role in the general discussion-relates with questions concerning built heritage and its vulnerability (red cluster), topics related with sustainability and climate change impact on heritage (green cluster), and thematic surrounding the relationship between heritage, community, development and disasters (blue cluster).

Qualitative Analysis
A qualitative analysis of the gathered results was employed in order to identify the clusters most related with the research question and the most recurring in the retrieved publications. This was achieved using VosViewer software and a content-based analysis.

VosViewer Analysis
VOSviewer provides a visualization of the relatedness between different text-based items-each corresponding to one publication-to better understand the relationships between the gathered results. The software achieves this purpose by grouping the different terms into clusters, allowing for a more efficient analysis. These clusters are assembled using the qualitative method of content-based qualification and are selected in line with the publications' keywords and main topics. Therefore, clusters are assembled by systematically inventorying and bundling each publication's keywords, abstracts and main topics. The closer two items are to each other according to an automated analysis of their text, the stronger their relatedness and, thus, the greater visual weight of each item [37], providing a visual representation of the weight of each semantic group, as well as the links between them. Figure 4 provides this analysis, from which three visual groups were formed (red, green and blue) based on interconnected content. Looking at the terms associated with each group, we can see that the thematic surrounding heritage-which is the most prevalent concept and plays a central role in the general discussion-relates with questions concerning built heritage and its vulnerability (red cluster), topics related with sustainability and climate change impact on heritage (green cluster), and thematic surrounding the relationship between heritage, community, development and disasters (blue cluster).
It is perceivable, through Figure 4, that a high number of links exist amongst each term, despite the lack of any close relationship between them (seen by the lack of any major proximity or overlap of any icon). Furthermore, heritage is not related specifically to ICH, being most connected with the terms community and city.
After the VosViewer analysis, and in order to aid the results analysis, a content-based qualification was made based on the full reading of the gathered results. This categorization allows for an understanding about which are the most consigned debates, the most specific topics addressed, and the most transversal thematic within the gathered results. It is perceivable, through Figure 4, that a high number of links exist amongst term, despite the lack of any close relationship between them (seen by the lack of major proximity or overlap of any icon). Furthermore, heritage is not related specific to ICH, being most connected with the terms community and city.
After the VosViewer analysis, and in order to aid the results analysis, a content-b qualification was made based on the full reading of the gathered results. categorization allows for an understanding about which are the most consigned deb the most specific topics addressed, and the most transversal thematic within the gath results.

Content-Based Analysis
For this section, the gathered results were read in their entirety in order to retr the main debates presented by the literature associated with ICH and urban resilience reading the results in its entirety, and taking the VosViewer analysis into consideratio was possible to perceive three main areas of debates in the gathered results concer intangible cultural urban heritage and resilience: sustainability and climate change; b heritage and its vulnerability; and heritage, community and development.
Due to the high number of retrieved results, not all papers will be referenced in section of the article, with only the most relevant results to each category being addres (a) Sustainability and climate change: Discourses related with disaster risk and climatic hazards are the most preva within the group of results, with 51 results addressing related issues. The discour characterized by the general recognition of the vulnerability of cultural heritage to disa risks and its associated consequences [38][39][40][41].

Content-Based Analysis
For this section, the gathered results were read in their entirety in order to retrieve the main debates presented by the literature associated with ICH and urban resilience. By reading the results in its entirety, and taking the VosViewer analysis into consideration, it was possible to perceive three main areas of debates in the gathered results concerning intangible cultural urban heritage and resilience: sustainability and climate change; built heritage and its vulnerability; and heritage, community and development.
Due to the high number of retrieved results, not all papers will be referenced in this section of the article, with only the most relevant results to each category being addressed.

(a) Sustainability and climate change:
Discourses related with disaster risk and climatic hazards are the most prevalent within the group of results, with 51 results addressing related issues. The discourse is characterized by the general recognition of the vulnerability of cultural heritage to disaster risks and its associated consequences [38][39][40][41].
The debate also presents an empirical approach to the challenges of disaster risks and climatic hazards, with many authors developing specific studies and tools with the aim of understanding and increasing resilience levels within specific case-studies, with the main goal of risk prevention and the elaboration of mitigation strategies [16,35,[42][43][44][45] The importance of local architecture preservation is the main approach within this speech, often associated with the bonds that buildings represent towards the preservation of specific cultural and natural characteristics of a community [46,47]. The authors of [41,48] define the sense of belonging and local identity as the link between inhabitants and a physical space, introducing the idea of "place attachment" and local communities as the safeguard of important values such as authenticity and identity, seen by the literature as intangible aspects of heritage. According to the same authors, the attachment to a site can also be defined as a sense of community, which has relevance once a territory is affected by disturbances such as natural disasters. The economic role played by the cultural built heritage is also addressed as a justification for the need to preserve it and make it more resilient in the face of disaster risk [48][49][50][51][52]. However, the weight of economic activities and the role of developers can have a destructive effect on a long-term basis, affecting the immaterial cultural heritage by disrupting a specific urban life through a process of gentrification, or through interventions that might be inadequate and intensify already existing injuries [53].
Concerning the role of cultural resilience in the face of urban sustainability and climate change, and the aim of overcoming its challenges, cultural heritage is often presented as a very valuable resource. Additionally, other topics, such as food heritage [46,56] and ecosystem services [57][58][59], are studied as tools for urban public health improvement, achieved by giving more attention to the specific environmental characteristics of heritage cities and its impact on local residents [60].

(b) Built heritage and its vulnerability:
The need for conservation and rehabilitation of the built heritage is another prevalent category in the gathered literature. Academics argue that preservation should be considered for the building of a sustainable city, since the conservation of cultural heritage has several positive impacts to long-term community sustainability. These impacts correspond to an increase in property values; the development of heritage tourism and the reuse of buildings and structures; the enhancement of the local economy and a tool to foster a sense of pride [61][62][63][64]; and for the enhancement of both tangible and intangible heritage [61]. In fact, the negative impact of urban planning on local culture can be avoided with the use of cultural heritage policy practices as tools to better bridge the gap between the traditional conservative vision of protection and a new forward-looking perspective of urban planning, living heritage, which includes more dynamic and intangible aspects. Therefore, urban heritage needs a city planning strategy to protect valuable landmarks, preserving monuments and the cultural identity of a place, which are constantly threatened by processes of urban development. However, most of the retrieved literature focuses on the destruction of the built heritage, while disregarding the role of ICH in their conservation approaches.
The recovery of the built environment can also be seen as a strategy aimed at preserving and enhancing cultural heritage and improving the quality of life, while favouring actions of community involvement [32]. The role of the local community is present on several conservation discourses, with [65] defending the idea that the new use of a repurposed historical building should be to attend to the immediate needs of the local community while providing users with a feeling of belonging and attachment to the place. However, the author believes that socio-cultural aspects are less prioritised for adaptive reuse projects since they are challenging to measure. On the other hand, [62,64] assert that a holistic approach must exist, one which empowers people to repurpose historic centres, and broadens the perspectives of interventions.
Cultural heritage-intended policies focused on conservation are also addressed and presented as a growing field in the literature. In [51], is an assertion that cultural heritage must be recognized as a feasible enabler for social welfare (legitimizing public expenditure for its protection and enhancement), while [66] defends that a sites abandonment and the physical decay of the built heritage poses problems about the policies to be adopted to manage and maintain historic buildings. In the face of these challenges, [67] states that a proper analysis of the built heritage will enable decision makers to better judge on matters of demolishing and adapting a building block and thus reduce building waste and increase sustainability levels.
The topic of post-conflict reconstruction is addressed in [68], while other authors present and proposes several preservation models such as an HBIM model [69] and the GIM system [70].
(c) The relationship between heritage, community and development: Even though heritage resilience discourses are still characterized by being heavily fragmented, it is possible to perceive two main lines of discussion present in the literature: the active role of local communities as representatives of intangible cultural heritage, and the need for a more holistic approach to dealing with cultural heritage issues.
Concerning the holistic aspect, the management of cultural heritage should be regarded more through an urban approach, since built and cultural heritage is usually not seen as part of the urban environment. On the other hand, conservation efforts are taken towards a perspective of specific buildings rather than a holistic perspective where cultural heritage is seen as an integrated part of urban environments [16,36,71,72]. In fact, and according to [69], urban heritage today aspires to address cities more holistically as inhabited and used places, characterized by a continuous process of change. Being managed sustainably with this perspective in mind allows the safeguarding and enhancement of their individual identities and competitiveness [72,73].
In respect to community participation discourses, heritage is articulated as both tangible and intangible, and the communities that inhabit historic cities are increasingly acknowledged by the literature as its primary stakeholders and custodians [72]. A more focused and strategic action must be taken by all concerned stakeholders, in a spirit of cooperation, to ensure that heritage is protected and that its role in reducing the risk of disaster and building resilience is recognized and promoted, since community-based approaches to cultural heritage are the most effective and sustainable [16,74,75]. Furthermore, the recognition of a complementarity between community and institutions is useful for the success of heritage-led practices [33].
Considering the role cultural economy and other related activities-such as tourism or festivals-have on ICH, the literature focuses heavily on the strategic role of culture as an economic development tool, used for the sustainable development of a place and the preservation of its cultural heritage [61,[76][77][78][79][80].
The role that the design of cultural and environmental goods has in valorising both material and immaterial cultural heritage at different scales is also addressed [77], with the merchandising product, often the victim of production stereotypes, being described as a collaborative actor with a disruptive force.
Also, the role of festivals is referenced by the literature since they provide one emblematic example of immaterial cultural heritage, by expressing artistic innovations in the cultural field and drawing on previous cultural background, perceived as accumulated cultural capital [80]. Furthermore, festivals are special events with a strong cultural component that can play a significant role in community life and economic development by being perceived as tourist attractions that revitalize local traditions, positively impacting living standards as well as the image of the city or region [79] related to its branding.
The role of museums as safeguards of cultural heritage and places to properly transmit cultural knowledge to the populations is also addressed [50,81,82]. Cumulatively, digital technologies are referred [78] to as a form of facilitating new ways of engagement with heritage and to allow local areas to highlight their history, potentially extending it to a wider audience, and to act as a driver of cultural and economic resilience, thus emphasising the role of stakeholder involvement. Considering the downside of economic activities in cultural heritage, [83] addresses the issues of the declining rural settlements in the face of globalization and growing urbanization, and the loss of a cultural landscape which it entails. The author proposes an innovative thinking to address the demographic, economic and cultural impacts on rural areas and its cultural heritage through more holistic and synergistic approaches to rural revitalization.

Discussion
The current study presented the results of a detailed examination of the literature concerning the relations between ICH and urban resilience. We have used a mixed-methods approach to evaluate the results and better understand which are the main areas of debate. Studies employing quantitative methods have been used, as well as qualitative evidence on content validity, which has been obtained from an SLR. This chapter discusses the main findings of this research.
Taking into consideration the research question and the three different types of resilience previously presented, all three categories showcased similar results. It can be concluded that the relationship between ICH and urban resilience is mostly characterized by an engineering resilience approach. This type of resilience is measured in terms of recovery, translated in the literature through ideas of heritage prevention, architectural preservation and recovery, a focus on the built environment, and an emphasis on conservation and rehabilitation as solutions to enhance and protect cultural heritage in the face of external hazards or exacerbated economic development. On the other hand, the evolutionary resilience approach is the least addressed by the literature, with only [33,41,57,63,82] embracing ideas related to the need of change and adaptation.
Nevertheless, the role of cultural heritage in supporting urban sustainable development and disaster risk reduction is recognized, along with the need for a heritage-driven resilience. There is a major emphasis of the debates on the material aspects of cultural urban heritage, as seen in the prevalence of the results concerning the impact of climatic hazards in built heritage, as well as the results concerning the debates of heritage conservation, which also justifies the prevalence of an engineering resilience discourse.
Furthermore, the idea of community participation is a cross-sectional thematic, where the community is seen as the representative and the main custodian of intangible urban heritage and its associated values, translated by the academics through references to identity and authenticity. The involvement of the local community is the focus of the debates in general, with the acknowledgment that urban cultural resilience is a shared project between local inhabitants and their elected representatives, while institutions are recognized as crucial elements for dialogue.
Moreover, despite the existence of a wide number of references concerning the need to inform and integrate populations, the role of education in valuing cultural heritage and understanding it as a tool towards urban resilience is lacking. Besides [84], the role of education is strongly attached to economic and cultural activities through publications focused on the role of museums as safeguards of heritage knowledge and its transmission. Even though the digitalisation processes and innovative methodologies applied by museums serves as an important tool to easily transmit knowledge through culture in an accessible way, it is essential for the literature to explore other ways of integrating intangible cultural elements as a way of educating local communities for the improvement of urban resilience discourses.
The debate is also characterized by being heavily empirical and focused on the elaboration of datasets, tools and frameworks applied for specific case studies in order to improve urban resilience and sustainability. However, here there is also the lack of a general framework which can aid the integration of ICH as a tool for interested parties to improve urban resilience approaches and methodologies.
Several gaps can also be identified on this field by the literature analysis. Firstly, the heritage issues are not integrated into larger political and urban environmental agendas [82] and cultural heritage is not taken as a factor when managing and dealing with urban resilience plans, although it brings a unique character and sense of identity and belonging for local communities and urban sustainability [85,86]. Moreover, there is a common sense of inefficiency when dealing with cultural heritage management, with customized methodologies and tools failing to properly integrate the concept of resilience and lacking a proper involvement of the population in the application of these same tools [41,43,87].

Conclusions
The current article aimed at answering the research question "How does intangible heritage relates to urban resilience?". The quantitative analysis showcased how intangible heritage related research is recent, with academic publications seeing an exponential growth from the year 2017 onward. It did so through a systematic literature review which identified 94 key publications classified in three categories: sustainability and climate change; built heritage and its vulnerability; and the relationship between heritage, community and development.
It is possible to conclude that a relationship between ICH and urban resilience exists based on the three different categories analysed in chapter 3. This study demonstrates the fragmentation and diversity of the debates when addressing the relationship between the two topics, with an existing focus on sustainability discourses, built heritage and the role of local communities. Moreover, there is a prevalence of discourses based on an engineering resilience approach. Most of the gathered literature which addresses this relationship focuses on the importance of conserving the local architecture and preserving monuments in the face of climate change and economic development. The relationship between ICH and urban resilience is also seen through the role of the local community, with community participation discourses articulating heritage as both tangible and intangible and being acknowledged as the primary stakeholders and custodians of heritage, safeguarding its authenticity, attachment and identity, and making them the main actors in urban resilience discourses. Economic elements of heritage are also considered, since these can translate the implicit cultural value of the intangible by making it something tangible and comprehensible through meaningful products and experiences that reference a common group of values.
The development of an SLR aims to minimize bias and improve the quality of literature data. However, some limitations may be taken into consideration, based on the selection of the databases used to export data and the search terms used. Furthermore, the selection process of the most important documents for full review is based on qualitative criteria of relevancy to the research questions which is subject to bias.
This study shows that there are still very limited perspectives on the topic of intangible heritage, specially concerning the already heavily recognized and important role that ICH plays when dealing with debates concerning sustainability and resilience. The authors recommend that future research takes into consideration this important role of ICH if this is to be properly integrated in urban resilience approaches, going beyond the idea of architectural preservation or community participation. Other expressions of ICH that can contribute in a positive way to urban resilience must be considered by urban actors, as well as researchers. This could be done by elaborating general frameworks which integrate definitions and recognising intangible heritage as a tool used to improve urban resilience, or by simply broadening and better integrating intangible heritage into urban heritage management and urban resilience plans, since its benefits are well documented by scientific research and international institutions such as UNESCO. This article proposes the recognition of the importance of ICH, and its use as a new paradigm for urban planners to achieve both urban sustainability and resilience, transforming urban planning approaches in the future. Data Availability Statement: The study did not report any data.