Culture, risk and the built environment
The principal aim of this chapter is to draw attention to the built environment as an arena for disaster risk reduction and to highlight the advantages of indigenous knowledge and vernacular architecture.
All disasters affect the built environment and many, like the earthquake that devastated Haiti in 2010, also exacerbate a housing crisis. The state of the built environment is a major determinant of risk.
Vernacular architecture is increasingly being replaced by structures built with non-traditional materials, especially reinforced concrete and concrete blocks. The result is often a deterioration in the structural integrity of buildings, a decline in traditional building skills and a loss of heritage.
The predicted scale of urbanization in the 21st century and the concomitant changes in livelihoods and technologies pose a challenge to the provision of safe, sustainable and affordable buildings. A particular feature of this rapidly changing built environment is the sprawling conglomerations in mainly the high-growth markets of East Asia.
People adapt the built environment over time to accommodate risk. This cultural adaptation, however, is shown to depend on three crucial factors: that the hazard is repetitive; that it allows forewarning; and that it inflicts significant damage. Most natural hazards reflect these criteria.
Vernacular architecture is often a trade-off between multiple hazards, as most communities are exposed to a variety of dangers and have to prioritize risk. But no architecture can be attributed to a single environmental threat. The main point is why, in hazard-prone areas, a particular method of construction is retained, able to adapt, often for generations.
If properly maintained, vernacular architecture continues to perform well under extreme conditions. The high death tolls in the earthquakes in Izmit, Turkey in 1999, Bam, Iran in 2004, and Haiti in 2010 were due more to the failure of contemporary buildings than to vernacular constructions.
The focus of government and NGOs after a disaster is often on building a large number of units with limited resources in the shortest possible time. However, to be successful, reconstruction needs to include local community input.
Culture is enshrined in the core values that inform the UN guidance that owners of destroyed houses should decide how they are rebuilt. Housing is a matter of rebuilding communities, restoring social and cultural capital, and livelihoods.
Poor decisions about the site of temporary settlements disrupt livelihoods and increase vulnerability. An owner-driven approach that involves community input and culturally acceptable building techniques is the foundation for reconstructing communities.
Cultural considerations are embedded in long-term reconstruction. Vernacular architecture can provide an important guide for building new houses, while the salvaging of materials preserves architectural heritage and community identity.
With earthquakes, the issues surrounding culture and tradition have often been neglected at great cost to responders and affected populations. Earthquakes are the principal naturally occurring force that buildings are designed to resist, and they occur without warning.
Many building codes are influenced by those first developed in the United States. Up to 95 per cent of the population in North America live in timber structures. There and around the world, timber construction is less vulnerable to collapse in earthquakes.
This contrasts sharply with most earthquake-prone regions of the world where the predominant form of construction is a frame with rigid joints between beams, and columns designed to resist lateral forces with unreinforced masonry infill. Reinforced concrete frame construction represents a transformation of the building industry around the world – a change so common that its risks are rarely discussed, despite the increasing earthquake casualties in reinforced concrete structures.
But what makes criticism of reinforced concrete moment frames as a system difficult is its proven strength and resilience on occasions.
The 2010 earthquake in Haiti revealed the urgent need to address the risks of reinforced concrete moment frame construction. The perceived failure of notable buildings in the capital, Port-au-Prince, created the impression that the death toll in the dense hillside settlements largely built of concrete block must be catastrophic, but more self-built slum housing survived than buildings of recent reinforced concrete construction.
If the reinforced concrete frame is top quality, its performance can be extraordinary, but this standard can only be expected in a small percentage of buildings now that such construction has become so common.
Interest in many different forms of vernacular construction is growing. In earthquake areas it has focused on traditional construction that demonstrates resistance to collapse greater than expected.
The embrace of concrete as the only ‘modern’ option often has been destructive of tradition. Restoration of the crafts needed in vernacular architecture can also help preserve culture.
New construction in Turkey increasingly includes reinforced concrete walls designed to resist shear. Confined masonry is a viable alternative. But retrofitting existing moment frame buildings with shear walls is very costly and involves the removal of the occupants for extended periods. Other less disruptive methods are proposed for these buildings.
During the relief phase, the emphasis by external assistance agencies on needs rather than capacities and the importation of standardized solutions can be counter-productive to local recovery. Likewise the control of resources and assumption of responsibility by external relief actors on issues such as shelter and housing recovery can inhibit the initiative of local households, leaders and institutions.
But the IFRC’s Sahel shelter project, for example, responded to the need for more culturally appropriate shelter solutions following concern about the poor performance and cost of imported tents and shelters.
Building cultures are always evolving. In particular, the shift from rural to urban culture has been a change from agriculture and subsistence to a largely cash-based system. Rural cultures are also in transition.
Disasters occur within this context of transition and may accelerate urbanization, adoption of new materials and change from joint to nuclear family households. A major crisis may also precipitate, for example, masons devising solutions to address weaknesses in buildings.
There is a risk in this accelerated period of change that valuable assets, knowledge and skills are lost, including through the demolition of traditional buildings. Local building culture may be undermined.
The time following a disaster is critical in the definition and redefinition of building cultures. It is a period of focus on construction issues – a process that can either promote traditional skills or reject them.
Assistance agencies and technical professionals involved post-disaster are key participants deliberation about building cultures and choices. External experts generally arrive to right the wrongs of inferior technology. But while many experts quantify losses, few investigate damaged buildings qualitatively, and fewer still document the ones that performed well.
There are exceptions when agencies have successfully regenerated local knowledge. One example is the use of quincha, a traditional system of lightweight cane panels, for both shelter and permanent construction post-earthquake in Peru by Practical Action.
A disaster may galvanize political and social will to take action to improve environmental management.
Critics of traditional construction on environmental grounds tend to miss the environmental impact and often poor climatic performance of modern materials, their relative energy efficiencies, and the potential increased lifespan of buildings through improved construction.
It is important that external assistance and interventions serve to help people make informed decisions about the built environment, but not at the expense of cultural criteria they value more highly than outsiders do.