Museologia Social e Urbanismo XXXVII

How do cities accumulate risk exposure?

Discussion prompts:

  1. What are the various components that constitute urban risk?
  2. How do these components get accumulated in urban areas?
  3. How can risk be reduced, considering the various components of urban risk?

Economic losses from disasters such asearthquakes, tsunamis, hurricanes or cyclones and flooding are now reaching an average of between 250 to 300 billion dollars each year. The global average annual loss to just urban infrastructure is estimated to increase to over 400 billion by 2030 with a massive expansion of urbanisation over the SDG implementation period. Cities not only concentrate economic opportunity, wealth, jobs, infrastructure, institutions and culture but they also concentrate risk and vulnerability that further exacerbates poverty, inequality and conflict. To understand how cities concentrate and accumulate risk over time, we first need to unpack what risk is composed of and how it is constructed.

Then we’ll talk more about how each of these risk components manifest in urban areas, we will then explore how cities offer the opportunity of reducing both everyday risk and the impacts of extreme events. For centuries disasters were understood as natural phenomenon or an act of god. Over the last few decades the global community has come to understand that most charismatic disasters also called intensive risks, from climate-induced storm surge like during Hurricane Sandy in New York to the earthquake and tsunami induced nuclear accident in Fukushima in Japan – all have anthropogenic causes. Everyday disasters or extensive risk from fires and household accidents are even more closely tied to vulnerability and human related causes that can be addressed by effective risk reduction processes.

Disaster risk can be understood in terms of its four primary components. First, hazard risks: Hazards are external forces from earthquakes, volcanic eruptions, cyclonic wind, typhoons and hurricanes and associated storm surges, avalanches and landslides, drought and extreme rainfall leading to flooding that arise from a variety of different sources acting in combination.

This could be ranging from geological, metrological, hydrological, biological and even technological sources. Many hydro- metrological events are becoming more frequent and intense owing to climate change. A recent analysis of over 600 major metropolitan areas with about a population of 1.7 billion people, that’s about a quarter of the world’s total population and approximately half of the global GDP, found that flood risk threatens more people than any other hazard. River flooding for example, poses a threat to over 375 million urban residents, while earthquake and strong winds could potentially affect over 275 million or 150 million respectively. Yet we must stop to reflect that the occurrence of an external hazard does not always lead to a disaster. The April 2015 Gurkha earthquake in Nepal of magnitude 7.8 killed over 9000 people and left the poor nation with economic losses of over 10 billion dollars, which is about half of its GDP. A much higher magnitude – 8.3 magnitude earthquake in Chile in September 2015 left only 14 dead with minimal losses.

Most losses in Kathmandu and Nepal are linked to poor-preparedness and lack of planning; high vulnerability with dense concentrations of people living in poorly constructed buildings. Systemic disaster loss, mitigation processes and investments in preparedness institutionalised in Chile over the last few decades, led to rigorous building codes and safer building and well-prepared evacuation systems which then limited vulnerability and loss.

Exposure to single or more usually multiple hazards is the other critical component of risk. People, property, infrastructure and economic activity are physically present in hazard prone areas and are therefore, subject to potential losses. If they were not in those locations they would not be exposed to those losses. With increasing urbanisation, cities concentrate both people and economic assets accumulating increasing hazard exposure over time.

Historically people have inhabited locations such as riverbanks like that of the Mississippi and New Orleans, highland cities (such as Shimla) and port cities (such as Istanbul) since they offered resource access, economic and socio-political advantages. Many of these locations were inhabited without enough long-range information about the hazards that they were exposed to. While it is difficult and hugely expensive to shift the location of an entire city because of hazard exposure, the more practical approach is to reduce exposure within the city by controlling land use that restricts building for example along exposed shore lines, flood plains or locations that are earthquake or landslide-prone. Cities particularly in low and middle-income countries often accentuate risk, especially for poor and vulnerable people who’ve limited choices of safe sites to live on. As the global population living in informal settlements continues to grow, risk exposure increases as low-income households are forced to occupy hazard exposed area with lower land values, deficient or non-existent infrastructure and absence of social protection and poor environmental quality. Large-scale urban infrastructure and economic investment decisions rarely consider the level of hazards in these locations or if they do; tend to discount the economic impact of their risk excessively so that short-term profits can be made.

This has led to large flows of capital into hazard prone areas and a vast increase in the exposure of the economic assets to earthquakes, storm surges, floods and other hazards. The concentration of investment in urban centres drives intensive risk while high levels of urban income inequality, shapes patterns of extensive risk. The third and potentially, the most significant, component of risk that can be managed and reduced through systematic policy action is vulnerability. Vulnerability is the inherent characteristic and circumstances of a community, asset or system that makes them susceptible to the damaging effects of a hazard.

There’re many aspects of vulnerability rising from physical, social, economic and environmental factors. Composite risk to all of these elements at risk can be reduced through a range of interventions-first, by reducing vulnerability: economic, social and environmental which is what much of the SDGs are targeted at, especially via the commitment to leave no one behind. Second, by reducing exposure by ensuring that people, buildings, infrastructure and economic activity are in safe locations, for example, by implementing planning regulations, discouraging habitation and economic activity in low-lying flood-prone areas. Third, by modifying hazard risk by moving settlements to less risk-prone locations for example outside a landslide or avalanche-prone zone or by constructing dams or enabling water recycling and conservation to reduce drought risk. A core challenge is not only to address all key risks as most locations are exposed to multiple risk but also think through trade-offs between them.

Another challenge is to systemically address every day or extensive risks that make up much of the losses experienced across the world especially by the poor and vulnerable.

These are often hidden, not reported by most official systems and the media, and are difficult to address through top-down means. Extensive risk manifests as large numbers of recurrent, small-scale, low severity disasters, community and local government led SDG processes are usually more effective at dealing with these small and localised events but they often add up to higher losses than the big earthquakes and storms that tend to grab the headlines. Growing global inequality, increasing hazard exposure, rapid urbanisation and the over consumption of energy and natural capital threatened to drive risk to dangerous and unpredictable levels with systemic global impacts. This presents a challenge to the achievement of the SDGs in areas that already experience social inequality and exclusion. This also makes extensive risk an important poverty attribute. The application of land-use and building standards that exclude low-income household is a common method of encoding social segregation into apparently technical planning criteria, for example, until its revision in the mid-1990’s the main building code system in Kenya continued the application of top-down colonial standards and paid too little attention to the affordability of these regulatory provisions. Prior to the enactment of Code 95 the cost of conventional building materials was beyond the reach of low-income and vulnerable groups, many of whom did not have access to housing finance and credit. No wonder that they were at risk!

More recently voluntary segregation has become a growing force with the proliferation of gated communities and the concentration of commerce in new shopping and business centres providing increased security against crime but also minimising the residents interaction with other social groups in the city. In urban centres risk is amplified by the interaction between multiple hazards, interdependence between economic activities, utilities and lifeline infrastructure, particularly in those cities that act as key nodes in the global economy and national markets.

For example, in cities with little built-in redundancy, failures in the power grid quickly spill over into telecommunications and transportation which in turn impact production, banking and even the informal sector. Urban areas however offer the opportunity for significant and systemic risk reduction and building resilience, particularly small urban centres and areas that are yet to be fully built up. Planning for integrated risk reduction, improved building and infrastructure standards, improved basic service delivery and lower poverty and vulnerability and significant improvements in institutional and community capacities can help mitigate future losses in a cost-effective and a viable manner. Many internationally accepted frameworks are also available to help local governments mitigate risk effectively. Through the Framework For Action – HFA contributed to a growing awareness of disaster risk. More than 2,000 cities had signed up for this by 2015. Under priority for Action 4, the HFA provided detailed guidance on the role of urban planning as well as building standards and the regulation of disaster risk reduction including the design of infrastructure and critical facilities such as hospitals and schools. Tools such as UN-Habitat City Resilience Profiling Program or the UNISDR Local HFA monitor and 10 Essentials offer municipal governments the means to better understand the strengths and weaknesses of the current approaches of managing disaster risks.

So what we’ve learned in the session?

Cities accumulate hazard exposure and vulnerabilities due to growing populations, increasing concentration, poor land use management, poor building and infrastructure specification and the lack of capacities to cope with the growing inequality and risk that we find in them.

The combination of speculative urban development and weak regulatory capacity leads to an increasingly social and spatial segregation of risk in cities especially in low and middle income countries. Apart from high-intensity, low-frequency intensive risks such as earthquakes and cyclones, extensive risk manifest as large numbers of recurrent, small-scale, low severity disasters which are mainly associated with local events like flash floods, landslides, urban flooding, storms, fires.

Unlike intensive risk, extensive risk is more closely associated with inequality and poverty than with earthquake fault lines and cyclone tracks. Risk is both constructed and amplified in urban areas due to the interaction between multiple hazards, interdependencies between economic activity, utilities and lifeline infrastructure, concentration and physical proximity. Urban areas offer the opportunity for significant and systemic risk reduction and building resilience particularly in small urban centres which are yet to be fully built out.

Planning for integrated risk reduction, improved building and infrastructure standards, improved basic service delivery and lower poverty and vulnerability along with significant improvements in institutional and community capacities can help mitigate future losses in a cost effective and a viable manner.



Sobre Pedro Pereira Leite

Investigador do Centro de Estudos Sociais da Universidade de Coimbra onde desenvolve o projeto de investigação "Heranças Globais: a inclusão dos saberes das comunidades como instrumento de desenvolvimento integrado dos território".(2012-2107) . O projeto tem como objetivo observar a relevâncias no uso da memória social em quatro territórios ligados por processos sociais comuns. A investigação desenvolve-se em Portugal e Espanha, na zona da Fronteira; em Moçambique e no Brasil. (FCT:SHRH/BPD/76601/2011). É diretor de Casa Muss-amb-iki - espaço de Memórias. Intervém no âmbito de pesquisa de redes sociais de memoria.
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