The September earthquakes

In September 2017, one of the most important seismic sequences in the recent history of Mexico occurred. On the 7th, at 23:49 hours (local time), an earthquake with a moment magnitude¹ (M) of 8.2 was recorded, with an epicenter at 133 km southwest of Pijijiapan, Chiapas (^{SSN, 2017a}). This was the fourth earthquake recorded with a magnitude greater than M8, which was also associated with a significant number of aftershocks.² This series of events seriously affected the states of Chiapas, Guerrero and, mainly, Oaxaca, in the area known as the Isthmus of Tehuantepec. The repercussions were particularly acute in the isthmian towns of Juchitan, Santo Domingo Tehuantepec and Ciudad Ixtepec, where, according to the Belisario Domínguez Institute of the Senate of the Republic (2017), a total of 23,304 homes were recorded as affected. Impacts on cultural heritage were also significant, the Instituto Nacional de Antropología e Historia (INAH) reported 587 damaged historic properties in the state, which means that Oaxaca concentrated 25% of the national total (^{Islas & Sánchez, 2017}; ^{Prieto, 2018})³. The Ministry of Culture estimated the national cost of the damage, without specifying the percentage corresponding to cultural heritage, at 1,700,000,000 dollars (^{Islas & Sánchez, 2017}; ^{Torres, 2021}).

However, in terms of social impact, the earthquake of September 7th and the sequence of aftershocks that followed surpassed any other seismic event on record in the region (^{SSN, 2017b}). While the magnitude of the phenomenon was remarkable, what was exceptional was the extent of its effects on the condition of the heritage, as there was no equivalent record on previous events of similar behavior. This motivated us to inquire about the additional factors that eventually intervened in the aggravation of the damage, so, as we will see later in this academic report, we decided to adopt a multi-hazard approach that would allow us to extend the analysis of property risk beyond earthquakes.

The institutional response

During the early stages of the emergency of September 7th, 2017, when the need to assess the situation was pressing, the INAH deployed in the affected area a series of multidisciplinary brigades, comprising mainly architects and restorers, and on occasions, archae ologists and anthropologists, whose purpose was to identify and quantify the affected heritage and to record the type and severity of the damage as well as carry out emergency actions of evacuation, protection, rescue and/or immediate safeguarding of the affected property, or at risk of further damage, due to the existing conditions of vulnerability at the time.⁴

From the experience of the brigades in Tehuantepec, we de tected, primarily through direct observation and first-hand contact with the inhabitants, both the need to deepen the knowledge of the set of risks to which the cultural heritage of the region is exposed and the urgency of developing strategies and coordinated actions between the local population and institutions to prevent or reduce situations that compromise it. In this sense, for example, we observed that in the city of Tehuantepec there is only one specialist in historic buildings; in addition, there is no fire station in the town, nor is there proper equipment for civil protection corps, for an emergency response. The sum of these fundamental deficiencies represents an acute vulnerability factor in terms of both care and prevention. In view of this situation, during the subsequent recovery phase, the INAH, in addition to restoring the historic buildings and the cultural assets contained in them, articulated through its national coordinating brigades a series of research projects, mainly anthropological, which sought to study the different risks that cultural heritage faces.

It is in this context, taking the seismic events as a starting point, but in their articulation with other risk factors derived from the local social context, that the present project arose, which focused on the detection and analysis of the risks to which the heritage of the city of Santo Domingo Tehuantepec is exposed.

Case study: Santo Domingo Tehuantepec

The selection of the case study was based on a series of geo graphic, spatial, and social characteristics of the city, with particular interest both for the relevance of its historical heritage in the regional spectrum and for the conditions that impact its future preservation. In the first place, the city of Tehuantepec has historically occupied a paradigmatic place in the cultural map of the Isthmus region, being a center of commercial confluence of the different ethnic identities and of communication between the populations of the highlands and the coastal plain, as well as an axis of social, political, and administrative reference. It is also a settlement with a long history of disasters caused by environmental phenomena such as earthquakes, tropical storms, and floods. Between 1787 and 1911, more than 100 seismic episodes were recorded with significant effects in the region (^{García & Suárez, 1996}). An example is the earthquake of 1787, which, according to historical sources: “in Tehuantepec, the same tremor ruined the church of St. Sebastian and broke the walls of the temple of St. Dominic” (^{García & Suárez, 1996, p. 162}).⁵

In this sense, seismic phenomena have had an important impact on the urban configuration and the built space of Tehuantepec. Among other factors, the seismological conditions of the region have influenced the architectural conformation of the traditional house, which comprises thick adobe walls and light wooden roofs and has a single floor in order to endure seismic movements (^{FAHHO, 2020}).

Also, that city is a territory historically hit by multiple hazards besides earthquakes (^{Torres, 2018}), mainly in its historic center. Although the entire region is considered of high seismicity, according to the national zoning of the Centro Nacional de Prevención de Desastres (^{Cenapred; National Center for Disaster Prevention, 2022}), other hazards are also parts of the city’s history, such as floods resulting from the rising of the Tehuantepec River and tropical storms (^{García, 2018}; ^{Reina, 2013}; ^{SSN, 2017b}). There are records of at least 14 floods or severe storms between 1599 and 1909 (^{García & Padilla, 2021}), for example, the heavy floods of 1599 caused by torrential rains that overflowed the main channel of the river and reached wide extensions of the town, recorded in the sources compiled by García:

the greatest flood that has been seen before or since [...] the floods caused such great havoc that it [sic] knocked down many houses, without sparing doors or roof beams [...] approaching the convent, which is half a league from the river, and on a hill or eminence, about twenty rods high [...] and the water was so strong that it kissed the steps of the churchyard, and the people who escaped by their feet [...] took refuge in the sanctuary of the church and convent; it took four days for the river to go down (^{Carriedo, 1847, pp. 83-84}).

More recently, from 2000 to 2021 alone, 27 emergency declarations for hydrometeorological phenomena were issued in the municipality of Tehuantepec, according to the Sistema Nacional de Información del Agua (Sina; National Water Information System) of the Comisión Nacional del Agua (^{CNA, 2022 [2000-2021]}).⁶

Equally important are anthropogenic hazards, such as fires, which have become frequent in the surroundings of the urban area due to intensive deforestation and the replacement of lowland rainforest with grazing land. These facts, together with the ac tual and potential occurrence of landslides, intense winds, and prolonged droughts, are high-risk factors,⁷ with the foreseeable effect of causing tangible and intangible losses in the Tehuano cultural heritage.

On the other hand, Tehuantepec is the city with the highest concentration of sites considered cultural heritage in the Isthmus region, with at least 26 registered religious precincts and more than 200 houses with cultural value, according to the Catálogo nacional de monumentos históricos inmuebles (National Catalog of Immovable Historic Monuments) of the Coordinación Nacional de Monumentos Históricos (^{CNMH, National Coordination of Historical Monuments, 2022}) of the INAH. Coincidentally, that city suffered a great deal of damage to its cultural heritage during the 2017 earthquakes. Speaking only of traditional houses with heritage value, 175 properties were counted with affectations (^{FAHHO, 2020}).

The sum of these geographical, social, and cultural conditions led us to consider Tehuantepec as the starting point of the proposed methodology, particularly in a post-disaster context, which showed an enormous vulnerability in the systems of management and care of cultural heritage. In fact, through the implementation of the first stage of the project, and the analysis of its results, we have sought to initiate a dialogue among diverse actors that will allow us to rethink institutional and citizen strategies for the protection and safeguarding of cultural heritage in the context of disasters, as well as to position the local population as the central element in emergency preparedness.

The pilot project: theoretical-methodological considerations

In Mexico, cultural heritage management and protection systems are often based on institutionalized notions of cultural practices and historic sites. Such practices assimilate the assignment of values (also understood as patrimonialization) as a centralized exercise exclusive to experts, but it leaves aside alternative visions or peripheral expressions of culture (Smith, 2009). However, the value system articulated in the discourse of cultural institutions, coupled with exploitation schemes based on tourism exploitation, has largely undermined broader social participation initiatives that had worked for decades. The loss of the notion of solidarity has produced an alienated version of individualism, without social responsibility, to the detriment not only of the conservation of tangible cultural assets, but also of intangible expressions. For this reason, the pilot project was built from an inclusive conception, starting with the local knowledge of what is considered heritage and the risks it faces.

The first phase of the project focused on strengthening the understanding of the risks to the cultural heritage of the first square of the city, based on Priority 1: Understanding disaster risk, of the Sendai Framework for Disaster Risk Reduction 2015-2030 (2015).⁸ To this end, participatory assessment and mapping methods and instruments were implemented, complemented by qual itative methodological tools, such as interviews, surveys and field observations, which, as mentioned above, made it possible to work based on local awareness of existing hazards. The tools will be discussed in more detail below.

Through the use of participatory tools such as risk mapping, the identification of sites of cultural relevance and the application of interviews, we sought to generate a change in the institutional discourse and, as a result, in the way in which the conservation of cultural heritage is perceived. Thus, throughout the project, the incorporation of notions such as co-responsibility, inclusion and representativeness related to the different local cultural expressions has been promoted from a horizontal viewpoint, with the aim of boosting a more sustainable practice of cultural heritage protection.

Finally, it should be noted that, although the primary hazard in the region undoubtedly comes from seismic activity,⁹ a multi-hazard approach was maintained throughout the project. This is based on previous research that has shown that cultural heritage sites often face losses due to unconsidered secondary hazards-for example, fire, landslides or floods-and the concomitance of several of these in compound disasters (^{Bosher et al., 2019}).

In this context, the work developed in 2019 was oriented, mainly through the identification and assessment of vulnerability factors based on community vision, to the analysis of the risks to which the Tehuano heritage is exposed. This sought to establish a solid foundation that would allow informed decision-making on possible solutions for risk reduction.

Participatory workshop

While conservative approaches have maintained a disaster response and recovery-based view of risk management, at an international scale (including the Sendai Framework itself)¹¹, the need to create strategies focused on risk prevention, reduction and mitigation before calamities occur has been raised. Based on this principle, a methodology initially developed by researchers in countries such as Japan, Georgia and Italy (^{Chmutina et al., 2021}; ^{ICCROM, 2020}) was implemented and transferred to the Mexican context as part of the Risk Management Subprogram for Cultural Heritage,¹² which allows obtaining information on local empirical knowledge about cultural heritage and its risks, as well as responses and forms of adaptation and perception of these and other contextual elements (^{Bayes et al., 2019}; ^{Chambers, 1994}; ^{Jigyasu, 2010}).

Thus, in July 2019 a workshop based on qualitative methods, consisting of the creation of a series of maps and other graphic resources, was launched in conjunction with key actors and members of the community (Figure 1). The municipal directorates of Built Heritage, Civil Protection and Works, and a representative of the Restoration Workshop of the Fundación Alfredo Harp Helú de Oaxaca (FAHHO), which was involved in the restoration of several damaged sites in the city, participated in the workshop. The workshop was applied by the authors, together with the MSc Mitzy Quinto-Cortés, who was invited to participate in the 2019 season. The main purpose of the workshop was to identify, analyze and discuss the possible vulnerability factors affecting the cultural heritage in the area of study, which was limited to the first square of the city, known as the historic center. The participants worked on the construction of three layers of information, namely:

(Photograph: David A. Torres, 2019).

FIGURE 1 Creation of participatory maps during the workshop. 

Vulnerability matrix

To conclude the workshop, a vulnerability matrix was created jointly by facilitators and participants through tfigurehe analysis and discussion of the information generated in the maps. This activity made it possible to unify criteria, problems, and areas of greatest cultural value, as well as to identify the main risks and red flag areas. As a result, a table (or matrix) was obtained, concentrating the information generated, including the critical risk nodes, the main hazards identified and both the challenges and areas of strength. Based on the knowledge and personal experience of the participants, lines of work, priority areas of attention and possible mitigation measures in the short, medium, and long term were also outlined (Figure 2).

Final thoughts

After analyzing the risk maps prepared at the workshop, the participants identified fire and seismic activity as the main hazards to cultural heritage, followed to a lesser extent by flooding. In terms of vulnerability factors, it was detected that the most important for a large part of the historic properties-which at the time of the study were at a very high risk of partial or total collapse-is the lack of maintenance, generally due to the absence of residents or users, or to the damage caused by the 2017 earthquakes. Some sites worth highlighting among the properties identified are the Santo Domingo convent complex, which includes the former 16th century convent and a historic buildings group for religious and residential use that surround it. At the time the workshop was conducted those had not been restored. It is appropriate to carefully analyze the fact that some historic properties that had already been restored at the time of the workshop, particularly residential houses, were also classified by the participants as vulnerable heritage. This is important because it reflects the mistrust that persists regarding traditional construction systems-in this case, adobe, biliguana,¹⁴ and tile (cf. ^{Cortés & Cruz, 2014}), which are closely related to the perception of risk. It will be necessary to assess this phenomenon in later phases of the project once the restoration buildings are done and reappropriated by the community. During the simulation of an emergency scenario, the participants also recognized the blockage of streets and main avenues caused by the irregular deposit of debris as a relevant risk factor. It was established that, if it is not avoided, it could represent a major cause of vulnerability during the emergency, since it would delay both humanitarian attention and cultural heritage rescue and protection efforts.

On the other hand, the routes of cultural importance that have to do with the course of the processions, the sites of celebration of the neighborhood festivities and the meeting points of the different territorial sections were identified as an essential part of the intangible heritage of the community. For this reason, they were established as a fundamental element, which at all costs would have to avoid being substantially modified or altered-to the extent of losing its symbolic value-by the processes of reconstruction and urban reconfiguration in the post-disaster recovery stage. This fact demonstrates that the tangible elements of Tehuantepec maintain a cultural value for the community due to their associations with immaterial components, but not intrinsically. Overlooking these latter components during the recovery process and throughout the preparation for future emergencies, would represent stripping the heritage of the very essence that makes it a necessary factor for conservation and rescue. As mentioned earlier, in addition to the seismic activity in the region, vulnerability to fires as a result of a lack of urban planning was identified by the participants as a priority. This vulnerability was detected in different points of the first square of the city, including the building that houses the municipal market, a fundamental axis of the daily life of both Tehuantepec and neighboring towns, also identified in the maps as a place of cultural relevance, owing to its relationship with the gastronomic identity of the inhabitants. The area was rated as particularly at risk, as it concentrates a large number of informal businesses that use gas stoves without adequate safety measures-mainly to prevent fires-, increasing the likelihood of an incident. This, together with poor management of waste and residues, accumulated both by the inhabitants and by the poor organization of the local municipality, considerably increases the vulnerability to fires and enlarges the area exposed to this hazard.

The above shows that the municipal market is not only an important element for the life and continuity of activities in the town, but that if it is affected by an incident resulting from a fire, or if it is severely damaged by an earthquake, it could trigger a series of cascading effects, escalating to a situation of greater severity and territorial extension. To this, it must be added that the participants indicated that Santo Domingo Tehuantepec does not have a fire station: emergencies are attended by the station located in the neighboring city of Salina Cruz, at least 30 minutes away, which represents another acute vulnerability factor.

In summary, participants identified the areas of greatest vulnerability to the hazards addressed, where earthquakes and fires are the most important around the convent complex and the municipal market, and although some others of lesser impact were discussed, such as floods, what was proposed to reduce them ended up focusing on reducing vulnerability to earthquakes and fires.

Regarding heritage care specifically, the creation of specialized brigades was proposed, as well as the creation of a warehouse or storage room for materials and for the temporary protection of heritage objects (such as the images of the saints in the neighborhood chapels). In addition, it was proposed to disseminate information among the inhabitants about existing risks and emergency activities on the one hand, and on the other, to create training activities aimed to different strata and sectors of the population, so that they can join the emergency tasks if necessary. Both proposals are strategies to strengthen preparedness.

Similarly, the urgency of addressing the damage caused by the 2017 earthquakes in historic buildings-many of them without a restoration project at that time-was detected in order to avoid greater losses. Of special attention was the recommendation to underpin and recover historic properties that were in apparent abandonment within the first square of the city, as is the case of the building known as the Chalet of Juana C. Romero. This pro posal was based on the recognition of the building’s cultural importance, despite the fact that it is in a state of semi-abandonment.

Another important element observed was the need to take action to improve the public electrical system, which due to its poor condition was identified as one of the main risk factors that may cause a fire and, with it, trigger other cascading effects, which would have the potential to cause even greater destruction. In contrast, the creation of a fire station in the city was not proposed, perhaps because it was perceived it was beyond the reach of the participants.