THE CLIMATE CHANGE RELATED ADAPTATION AND RESILIENCE OF TRADITIONAL TRADICIONAL DWELLINGS: THE CASE OF THE YUCATAN PENINSULA

Mexico has been affected by extreme events such as storms, hurricanes, floods, and wildfires in the past ten years. In this paper, we will attempt to respond to the following questions: What are the climate change effects on the architectural heritage of Maya housing, and what are the adaptation and resilience practices of Maya housing and its environment? 
Maya houses have major climate variability adaptation potential. The building of a Maya home is conducted without architects, but with the intensive labor required for the planning, organization, technology and systematic knowledge of the climate on the part of the various artisans involved. These efforts, which we can observe to this day, implied invention, innovation and adaptation, as well as the oral transmission of knowledge for locating and orienting the home, preparing the terrain, seeking out and preparing construction materials, the actual work of building the house and conducting the related construction rituals. There exist various forms of adaptation, among them the form, design, materials and technology used. Here we review the housing’s adaptation and resilience to floods, and both water management and control. 
The principal objective of this text is to evaluate the adaptative and resilient processes of Maya housing to the effects of climate change, considering the principal criteria / indicators that might affect the habitat’s internal environment, its constructive structure, the materials and the inhabitant’s comfort, but without changing the Maya house’s basic design patterns.


Introduction
Hurricanes have been recurrent in the Yucatan Peninsula since pre-Colombian times and especially since the 1980s. Between 1980 and2005, 9 cyclones were considered disasters in the Gulf of Mexico and the Caribbean. Two of them, hurricanes Gilbert (1988) and Isidore (2002), were particularly destructive.
Over time, the traditional Maya house has deteriorated in some respects, but has yet to disappear. Its flexible structure and renewable materials (the guano palm for the roof, for instance) make for the Maya house's vulnerability to the effects of hurricanes, but it also has especially high adaptation potential. Rather, the traditional Maya house is being threatened by post-disaster reconstruction programs under which governmental authorities draw on a disaster fund (FONDEN) to rebuild such houses with cinder blocks, completely ignoring the patterns and traditional conception of the Maya house. Although the new 24 m2 house is more resistant to cyclones given its concrete slab roof, in the process traditional and local knowledge is lost along with the cultural elements of the dwelling and its adaptability to hydrometeorological hazards. The heritage of the Maya vernacular house is therefore in danger of disappearing because public reconstruction programs have failed to integrate the traditional elements of the Maya house into the new one. Thus, we are led to demonstrate the following hypothesis: The Maya houses that were destroyed by hurricanes were poorly maintained and poorly built; their replacements were able to withstand cyclones with limited damage.
The current problem is related to Maya housing's adaptation to climate change effects. In order to conduct this study various indicators were considered in relation to the dwelling and its relationship with the environment, geographic location, temperature, illumination, ventilation, orientation, construction systems and materials, sanitation, as well as the other social and economic conditions prevailing in the region, which would provide an approximation of the transformation and climate adaptation the house has experienced. There exists no "theory" of climate change adaptation, however the fields of anthropology and history have produced various theoretical postures on the subject such as that of Virginia García Acosta 1 , who proposes that "societies around the world and throughout history have formulated social and cultural paths for managing risk and confronting real and potential disasters. " Some groups have developed strategies for adapting to environmental, social, technical and cultural change. In this manner the dwelling has adapted to different contents. For that reason, disasters are non-linear, complex, multi-cause and multifactorial processes.

Theoretical framework: adaptation and resilience to climate change
We need to reflect on the dialogue between "to inhabit" 2 and climate change effects. Since time immemorial there was awareness of the environment as a determining factor in the culture and development of peoples and that the dwelling formed part not only of the material culture of peoples but also served as an intrinsic element in their development. It is very difficult to deal with this issue without taking into account the various disciplines that have made major contributions to the science of architecture and urbanism.
We have learned from the field of architecture to dialogue with history and the environment. The dwelling, in particular, has to be located in space and time. The anthropologist of Polish origin Amos Rapoport 3 had posited that climate does not determine the dwelling, but rather represents an important component. In the field of sociology, we are indebted to P. Blaikie, F. Cannon, I. Davis and B. Wisner 4 , as well as Alan Lavell 5 and Omar Cardona 6 , who have considered both at-risk and vulnerable societies. In the field of disaster history studies, Virginia García Acosta 7 and her colleagues have argued for the importance of historical perspective in analyzing climate events.
Patrick Pigeon 8 , Jesús Manuel Macías and researchers from the del Instituto Mexicano de Technología del Agua (IMTA), such as Denise Soares 9 , have contributed methods and reflections regarding climate and hydrometeorological events. The work of these researchers demonstrates just how permeable are the transdisciplinary borders in relation to the dwelling and its relationship to the climate and "extreme" climate events. Nevertheless, from a theoretical point of view there exists a contradiction: the dwelling is a process whereas climate is a phenomenon. This is a methodological distinction; the dwelling is studied as a social and technical process, while climate variability is approached as a natural phenomenon in which anthropic actions have altered its development.
We can find the theoretical foundations relative to climate and the adaptation processes of vernacular housing, primarily in the writings of three authors: Amos Rapoport 10 , who regarded climate as a modifying factor of vernacular housing; Paul Oliver 11 , who revealed the need for a new focus on vernacular housing and climate change adaptation; and Valeria Prieto 12 , who conducted the first study on the importance of vernacular housing in Mexico.
Rapoport is constantly amazed by the knowledge and abilities displayed by builders in their choice of sites and climate-adapted materials, and in their adaptations of the traditional model to micro-local climate conditions. In the field of architecture there is a sustained theory of climate causality and of climate requirements determining the form. Rapoport questions this opinion, mentioning the determining role of climate in the creation of the built form while also recognizing that the role of culture is, on numerous occasions, more important than that of climate and, as a result, he questions in this way all extremely determinist opinions. However, the existence of adaptive climate solutions in traditional societies confirms that while climate might not be determinant, it serves as a modifying factor. Paul Oliver 13 emphasizes that "primitive construction" remains the absolute archetype and its forms are interpreted as precursors of the architecture of the great, so-called "civilized" societies, when they are product of a culture and of climate change adaptation. This archetype is linked to the concept of "primitive man, " hence their constructions are deemed "primitive. " The road to recognition of the mere existence of construction forms destined for domestic uses -now referred to as "vernacular architecture"-susceptible to being differentiated according to the location's cultures, environment and climate is one that we can more or less date back to the second half of the Twentieth Century. P. Oliver 14 recognizes that climate modifies the concept of some buildings with the problem being the extent to which it is possible to determine whether the response has been a success or failure as very few traditional constructions have been the subject of scientific studies for determining such results. 10 Rapoport A., House, form and culture, Prentice Hall, NJ, 1969. 11 Oliver P., Cobijo y sociedad, Blume, Madrid, 1978. 12 Prieto V., Vivienda campesina en México, SAHOP, México, 1978. 13 Oliver P., Cobijo y sociedad, Blume, Madrid, 1978. 14 Oliver P., Dwellings, Phaidon, Londres, 2003.
Valeria Prieto 15 believes that climate conditions constitute one of the main reasons for housing. She states that popular knowledge has been improving on housing designs for adapting them to each climate, and that the process of climate change adaptation is not the result of a sudden decision, but rather of a long process of trial and error.

The local context: climate and hazards
The Yucatan Peninsula has a 1,941 km coastline with 425 km corresponding to the state of Campeche, 340 km to Yucatan con and 1,176 km to Quintana Roo. (Fig. 1) In the case of the Yucatan Peninsula, Gilberto proved to be one of the most devastating hurricanes ever to affect the Yucatan given its intensity (category V), producing winds of over 225 Km/h. A compilation of climate events related to hydrometeorological phenomena on the Yucatan Peninsula between 1464 and 1900 identified a total of 19 extreme events were identified over that 436 year period including hurricanes, excessive rains, epidemics, hurricanes and hail storms; that is a relatively low number of such events excluding the damage inflicted during historical processes manifest over time. Between 1955 and 2016, 39 events consisting of hurricanes, and both tropical depressions and storms were registered in that 61 year period, which is a relatively minor count compared to the mere 19 such events that occurred over a period of 436 years. 15 Prieto V., Vivienda campesina en México, SAHOP, México, 1978.

The Maya house and its setting
According to archeological sources, the Maya house has been in existence for 3,000 years. The choice of materials and the typology were the result of an extended evolutionary process. Despite the urban changes introduced since the Spanish Conquest, the Maya family unit and the solar have persisted throughout history, right up to the present. The solar encompasses the actual house, the kitchen, milpa plot, orchard, vegetable garden, and the corral for the livestock.
The Maya house can be defined by its architectural design and the materials employed in its construction. The following forms have been identified: Apsidal floors with waddle and daub (bajareque) walls, apsidal with stone-work masonry walls, apsidal with walls made of colox-che' 16 unfinished, a rectangular base and waddle and daub walls, a rectangular floor with masonry walls, and a rectangular floor with colox-che' walls unfinished.
The types of houses on the coastal zones include a rectangular floor with walls made of wood and guano palm, a rectangular floor with masonry walls and a guano roof, and a rectangular floor with masonry walls and Marseille style clay tile roof.
The traditional Maya house is closely linked to the local ecosystem. The traditional architecture not only responds to climate conditions, but also to various factors related to the socioeconomic and cultural environments. Studies have shown the persistence of a single model of construction from the pre-Colombian period to the present day. These include Shattuck (1933); Redfield and Villa Rojas (1934) and Wauchope (1938); and Dapuez and Baños (2004). The traditional type of construction can be found throughout the Yucatan Peninsula.
Diego de Landa did not leave us any description regarding the shape of the houses he encountered so we do not know whether just prior to the Conquest they were oblong or rectangular. However, he does mention in his Relaciones de las cosas de Yucatan (Yucatan Before and After the Conquest), the way they were built with the roofs made with abundant palm fronds to keep rainwater from seeping in, and affirms that they were resistant.
Her also mentions hurricanes that flattened high and low-lying houses alike 17 . However, some houses were consumed by fire as their inhabitants had built fires inside the houses as the hurricane hit in order to shield themselves from the cold, but under the impact of the intense winds the waddle of the walls caught fire. Nowadays, the threshold of traditional homes is not very high as a person must bend to enter, but the guano palm roof is well elevated (though they may still catch fire in the event of pyrotechnic displays) and it retains a level of thermal comfort within. There is a possibility the Maya house can be adapted for powerful winds.
While the walls of the Maya house may be built from trunks, stones or waddle and daub, both the guano palm roofs (Sabal mexicana, Sabal yapa and Sabal mauritiiformis) and the basic structure are comprised of diverse types of wood. The house is approximately 4.5 m wide, 8.0 m long and 4.5 m tall. The roof contains structural elements that allow it to resist hurricanes consisting of two pairs of thin crossbars that serve as roof bracings (called Alka' ch' o (belcho'). It is possible to use 45 different species of wood for the 22 structural parts (walls and roofs). These are divided into two groups: structural timber and the more flexible ones that are given non structural applications. In the coastal region of San Felipe, Río Lagartos and Las Coloradas, the wooden houses are made from pich (fam. Fabaceae, Enterolobium cyclocarpum) or black zapote wood (fam. Ebenaceae, Diospyros digyna).
The Maya house is adapted to the environment and to hurricanes. This adaptation is due to the: -Accessibility of local construction materials.
-The wood and guano palm fronds are appropriate for changing temperatures and humidity levels and they provide barrier against infrared and ultraviolet rays and radiation.
-The materials used in the walls maintain a comfortable temperature within.
-The houses can be dismantled and moved to a different location.
-It requires a collective effort.

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The climate change related adaptation and resilience of traditional tradicional [...] Fig. 2 Maya house with masonry and waddle-and-daub walls Traditional houses are resistant to the strong winds of hurricanes. Their structures afford the structural flexibility that allow them to resist intense winds, with the main probable damage consisting of the roof structure possibly leaning away from the wind gusts or the light guano palm fronds being stripped off. The apsidal base and the steeply pitched roof provide wind resistance, helping to easily deflect and divert the wind.

Maya housing's adaptation and resilience potential in relation to the climate and climate change effects
The two main consequences of climate change that impact the coastal areas of the Yucatan Peninsula are rising sea levels and changes to maritime climate (increasing frequency and intensity of storms and hurricanes).
The Fourth Assessment Report of the United Nations Intergovernmental Panel on Climate Change estimated that sea level rise for 2010 will range between 18-38 cm (in a low scenario) and 26-59 cm (in a high scenario), based on multiple emissions scenario models. Climate change will increase flooding and costal erosion going forward. Moreover, more frequent and intense tropical storms and hurricanes are expected, including major storm surges that could also contribute to sea-level rise of 4-6 m or more, which would have a major effect on the coastal states of the Yucatan Peninsula. Such tides could expand the extent of impacted areas by 11 km to 16 km inland in the case of low lying areas (1 -2 m above sea level).

a) Resistance to hurricanes and precipitation
Since the pre-Colombian era the inhabitants of Mesoamerica suffered the adverse effects of tropical storms or hurricanes. The god of rain, Tlaloc, appears in one form or another in all Mesoamerican cultures, from the Olmecs at the dawn of the Preclassic period through to Classic Maya culture. In the state of Yucatan and the larger Maya region, hurricanes were the protagonists of cosmogonic myths, as well as in their religions and calendar rituals. From there these myths extended north and south, to wherever there were tornados, dust storms, whirlwinds and waterspouts.
Bartolomé de las Casas interestingly observes in his Apologética historia sumaria that "the Indian's houses with woven vines, which is to say their huts, proved more resistant to hurricanes than those built by Spaniards with boards, heavily festooned with nails". This suggests an early technological adaptation strategy by the indigenous Caribbean peoples against hurricanes.
In this rainy tropical climate, a roof that quickly sheds water is essential for Maya homes: there are two to four sides to the steep pitched roofs to allow water to be quickly repelled from the house. In some cases, builders leave openings along the ridge beam to allow hot air within the house to escape 18 . Surrounding plantations, including palm and banana trees and bamboo, also provide protection from hurricanes. The guano palm has a degree of wind resistance. The Maya house is generally located in the lower part of a relief to limit the potential impact of a hurricane.
On most of the peninsula you see four sided roofs that are rounded in an apsidal pattern to provide the greatest possible wind resistance. The roof 's height allows it to trap heat while affording cooler temperatures below. (Fig. 3) Dr. Damaso Rivas, a researcher who was born on the Yucatan Peninsula, has recognized the importance of the relationship between the climate within Maya housing, stating that the structure of the ancient Maya's houses includes articulated and flexible characteristics that make them resistant to natural phenomena such as hurricanes 19 . He has worked to revive and develop a new appreciation for Maya housing, citing characteristic elements such as the use of wood and guano that are regarded as sustainable.

b) Adaptability to drought. Ancient and current rain ceremonies
Ceremonies in the Yucatan for attracting rain have been mentioned by various authors 20 . In this context it is understood that there were ceremonies for conjuring the rain. When periods of drought proved to be prolonged it was necessary to conduct rituals for the god of rain Chac. The Maya turned to their priests.
In contemporary Yucatan some rain ceremonies persist (Chak-Chak) such as the one described by Mario Humberto Ruz 21 in the village of Tixhualahtún in eastern Yucatan: The h-men prepare the scenario: an altar-table that represents the communal space (Fig. 4), covered with jabín leaves and with the feet of the altar-table firmly rooted in the ground, thereby affording communication with the underworld. Vine arches are erected at each corner. The arches are erected at each of the cardinal points to represent the abodes of the chaako' ob, the rain lords. A cross is placed in the center of each arch from which to hang the gourds that will hold the offerings. The gourds are symbolically linked to the celestial sphere that is symbolically extended on the altar. Once the scene has been arranged, the ceremony is held primarily to assure enough rainfall for the crops and the milpa.
The work of looking for the timber, vines, and water from wells is a community effort reserved for the men. The ritual liquor and the bread made of think layers of maize and ground pumpkin seeds are prepared. The second day the h-men pinch the maize dough brought by each of the participants, and place a bit from each. In each of the arches are placed offerings of vegetables, maize, cacao, balché 22 , tabaco, squashes and leaves. Later, the h-men begin their incantations to the rain god. At the conclusion of the ceremony, the altar is dismantled. No one doubts that the rains needed to nurture the milpas are far off.

The Ka' anche'
Is a 3 m2 bed made using trunks from the region as well as vines, agaves and grasses to an elevation of 1.50 m. The construction techniques are based on traditional knowledge transmitted from generation to generation. It is generally built as a rectangle ranging from 1.50 m to 2.00 m in length, 1.00 m to 1.50 m in width, and 1.50 m to 2.0 m in height. It is a form of drought adaptation, allowing for cultivation of fruit and vegetable species in a confined and controlled space protected from insects and animals as well as drought. It is one component of the traditional Maya dwelling, integrated as it is into the family compound and is generally located near the family well to facilitate irrigation.
Several authors 23 mention the Ka'anche' , which is used as a ritual table used in the Chak-chak ceremony conducted each August to beseech the rain gods to deliver rainwater to the milpa. The existence of this ceremony is testimony to a history of extended drought in Yucatan. Herman W. Konrad argues that the destruction of the Yucatan Peninsula forests was caused not only by tropical storms and hurricanes, but also by slash and burn agriculture. He also suggests that the success or failure of subsistence strategies in this region depended on the Maya's effective adaptation to the ecological effects of drought and both tropical storms and hurricanes, as suggested by the Ka'anche' technology.
We should also take into account that in pre-Colombian times the Yucatan Peninsula experienced extended droughts. For example, Gill's hypothesis 24 is based on an explanation for the disappearance of Maya culture resulting from drought in the lowlands between 800 and 1000 CE, and is supported by data and confirming evidence from various disciplines: meteorology, volcanology, paleoclimatology, geology and hydrology. More recently, and possibly in response to climate change effects, there were prolonged droughts during 2008-2011. 22 Balché is an alcoholic beverage made using fermented balaché bark and wheat. 23

Chultuns
One of the Maya's main technological responses to drought were the canals used to drain excess water from flooded land while retaining the soil's humidity, and the harvesting of rainwater. The storing of water in underground chambers called chultuns, and the systems leading to canals depended on permanent drainage and the capture of seasonal runoff. It has been shown that the two main components of water exploitation, canal building, and construction of irrigation ditches and reservoirs predated the rise of monumental architecture.
Brainerd proposed that the chultuns were already functioning by the Early Classic period (250-600 CE) and that at least by the Late Preclassic (300 BCE -CE 250) they were being built, which is to say that the chultuns already existed in the period when the greatest droughts were experienced, 800-CE-1000 CE. The term chultun, which means a cistern carved from rock to retain rainwater, is made by a contraction of the words chulub (rainwater) and tun (carved stone), according to the Maya Cordemex dictionary.
According to Zapata Peraza a chultun is comprised of (a) a catchment area; (b) mouth; (c) neck; and (d) bed. The catchment area consisted of a slightly inclined apron surrounding the mouth and extending five meters in diameter, thereby guiding the rainwater inward. The mouth generally consists of a monolithic circular ring through which the water enters.
It has a lid made of rock or wood. The neck is divided into two parts: the upper level consists of a ring of stucco-bound stones, and the lower level of bedrock. The neck's entire surface is encased in stucco. The bed comprises the deposit and its walls are always covered with stucco. Maya builders observed that sandy limestone rock was to be found below the superficial layer, and therefore most chultun cavities were formed out of this easily managed material. (Fig. 5)

c) Flood adaptation
Like other countries, Mexico experienced in 1998 and 1999 the warm phase of the El Niño-Southern Oscillation in the form of torrential rains that led to flooding. A study conducted by the Centro de Investigaciones and Estudios Superiores en Antropología Social (CIESAS) has recorded drought and flooding phenomena from the Pre-Colombian period up to the late Nineteenth Century. In that context, the inhabitants of Mesoamerica have had to adapt their houses to recurring floods, especially those located in humid tropical zones. Rainfall averages 760 mm per month in Mexico, but 68% of normal precipitation falls between the months of June and September (CONAGUA).

Conclusions: the traditional Maya house's adaptability
The dwelling does not control the climate, however, it is possible to control and modify the climate within the dwelling even when it is being affected by an adverse outside climate. The inhabitant can control the climate inside the house by means of the materials employed in its construction, as well as its form, and adjacent services and systems. When we speak of climate change adaptation, we are refering to an action taken to affect the conditions within the home, thereby drawing a clear distinction between internal and external space.
One indicator that allows us to understand the habitat/climate relationship is directional orientation. Mesoamerican societies position themselves facing west, with north situated to their right and south to their left, in contrast to the European tradition of using North as the key cardinal point (by which convention cartographers draw standard maps with north at the top). In this tropical forest terrain, hunters can get their bearings in relation to rivers. It is a hydrographic means of orientation rather than the cardinal points used by people in deserts and on the plateau or Antiplano.
The house's orientation depends on the same spatial concept 26 . The geomantic site corresponds to the geographic one, as explained by Pézeu-Masabuau 27 with regards to the Japanese house.
The social adaptation strategies identified within a contemparaneous Maya family from Cobá shows that the technological adaptation processes were linked to social processes: family or community management of chultuns could only be effective in an organized society sharing an autonomous technologial process. Hence, the combination of social and technological drought adaptation strategies would have made it possible for the Maya to subsist up until the time of the Conquest.
The traditional dwelling is under threat of extinction. Maya housing is being replaced, little by little, with homes built of cinder blocks and concrete slab. In fact, everything is converging toward erasing this heritage: Few strategies exist for the protection of the Maya habitat from hurricanes. In the absence of a specific home improvement program, and despite the inhabitants recognizing that traditional homes are more inhabitable and better adapted to the tropical heat, they plan to rebuild them with walls made of cinder blocks and concrete roofs. As we have been able to show, walls made of such concrete masonry units lack resistance to saltpeter, but the inhabitants do not clearly perceive this phenomenon.