Hazards and the Built Environment

Attaining Built-in Resilience

Lee Bosher

• Publisher: Routledge
• Year: 2008
• eBook ISBN: 9781134090471
• Edition: 1
• Topic: Business
• Subtopic: Business General
• Index: Business

As a specialist in disaster preparation, you have huge responsibilities: a failure to prepare for natural and human-induced disasters costs lives and money. When a natural or human-induced disaster hits a built-up area the amount of damage it does will depend largely on the extent to which the built assets in the area were developed to withstand it. To fail in this respect is therefore both ethically and financially negligent.

What kinds of structural and non-structural alterations can be made to protect buildings from large-scale disasters?

How can we reduce the threat of these disasters, as well as the damage they cause?

Presenting seven guiding principles, drawn from a broad range of disciplines and approaches, this book tackles the difficult questions about what can be done to attain built-in resilience. With contributions from many renowned experts and upcoming researchers in the fields concerned, it comprehensively assesses the wide range of issues faced by practitioners. Whether you're studying construction management, researching hazard resilience issues or working on construction projects in hazardous regions, this book is for you.

Part I
Introduction

Chapter 1
Introduction

The need for built-in resilience

Lee Bosher

Introduction

Recent natural and human-induced events have highlighted the fragility and vulnerability of the built environment to disasters. These physical systems have traditionally been designed, built and maintained by the myriad professions involved with the construction industry. Therefore, designing and constructing a built environment that can cope with the impacts of disasters demands an in-depth understanding of the expertise and knowledge on avoiding and mitigating the effects of hazards in order to secure a more sustainable future (Hamelin and Hauke 2005; Bosher et al. 2007).

This introductory chapter provides an insight into the prevalence and impact of disasters that occur globally and questions whether ‘natural disasters’ are really natural events. The observed shift in the way disasters are being managed is also discussed, explaining the move away from the reactive attributes of Disaster Management towards the more proactive Disaster Risk Management (DRM) approach that should be ‘mainstreamed’ into developmental initiatives. The function of a multitude of disciplines responsible for how the built environment is delivered is therefore a critical aspect required for the mainstreaming of DRM into long-term development. This chapter will discuss why the attainment of built-in resilience is important, highlighting the structural and non-structural aspects of hazard mitigation and justifying the need for the multi-disciplinary approaches advocated by this book.

The prevalence and impact of disasters

A ‘disaster’ is defined by the United Nations International Strategy for Disaster Reduction (UN/ISDR 2004: Appendix 1) as:

A serious disruption of the functioning of a community or a society causing widespread human, material, economic or environmental losses which exceed the ability of the affected community or society to cope using its own resources. A disaster is a function of the risk process. It results from the combination of hazards, conditions of vulnerability and insufficient capacity or measures to reduce the potential negative consequences of risk.

Threats to society and the built environment are diverse and include extreme natural hazards (such as earthquakes, floods and storms) and human induced hazards (such as terrorist attacks, explosions at industrial facilities and mass transportation accidents). Natural and human induced hazards may not only threaten the lives of those unfortunate to become affected by them but can result in disasters that can also threaten economies, businesses and in some cases political regimes. The impacts of disasters also drain millions of dollars every year in relief, rehabilitation, reconstruction and insurance costs for many nations.

Figure 1.1 illustrates the huge figures related to the estimated damages caused by disasters by continent over the period between 1991 and 2005, with the total reported damages totalling nearly US$ 1,193 billion and the worst hit continent being Asia (EM-DAT 2007).¹ The costs of these damages averaged US$ 79.5 billion per year (EM-DAT 2007) and had a particularly devastating effect upon the economies of underdeveloped nations and their development strategies.

However, the economic costs of disasters are only one part of the problem, with the impacts on human life being the most fundamental and distressing elements of the effects. Figures obtained from EM-DAT (2007) indicate that between the years 1991 and 2005, on average 231 million people per year (approximately 3.5 per cent of the world’s population)² were affected by various types of disasters. Disasters wreak havoc on nations irrespective of a country’s wealth or resources but invariably it is the least developed nations that suffer the most.

Figure 1.1 Total numbers of reported disaster related damages by continent (1991–2005), figures in US$ millions

Palakudiyil and Todd (2003) make the observation that during the decade between 1992 and 2001, the least-developed countries³ lost on average 1,052 lives per disaster; while the average deaths per disaster for countries with medium or high development were 145 and 23 respectively. In addition, of the total number of people reported killed by disasters during the same period 75 per cent of the deaths were in Asia and 67 per cent were in the least-developed countries while only 4 per cent of the deaths were in nations with high levels of development (Palakudiyil and Todd 2003). The statistics indicate that people who live in countries with a low level of development are (on a global scale) the most likely to be affected and killed by disasters.

Natural hazards

Natural hazards are typically split into two categories, namely; (1) geohazards, and (2) hydro-meteorological hazards. Figure 1.2 provides a list of the key geo-hazards and hydro-meteorological hazards that occur globally. The magnitude of natural hazards tends to be determined by key factors such as meteorology (which is influenced by the changing seasons), topography, hydrology, geology, biodiversity (of flora and fauna) and tidal variations (caused by lunar and meteorological influences, coastal topography and influenced by the type and locality of coastal developments). These processes are typically benign and provide the basis for people to exist in harmony with their natural environment. However, infrequently (and some would suggest more frequently) natural hazards impact upon the built environment, causing damage, deaths, disruption and financial losses. There is now a broad scientific consensus (including from the Intergovernmental Panel on Climate Change) that the global climate is changing in ways that are likely to have a profound impact on human society and the natural environment over the coming decades (Solomon et al. 2007). Commentators have posited that the impact of global climate change (which is arguably both natural and anthropogenic in nature) has increased the frequency of disasters, and will further increase the frequency of such events in the future (Munich Re 2003). The impacts of these natural events can be psychological, sociological and political but are typically reported in economic terms⁴ and as such, economic losses due to the impacts of natural hazards have increased ten-fold in the last 40 years (Munich Re 2003).

Geo- hazards	Natural hazards
	Earthquakes
	Volcanic eruptions
	Tsunamis
	Landslides (incl.all kinds of mass movements,cavity collapses and ground failure)
Hydro- meteorologal hazards	Floods
	Coastal erosion and flooding
	Wind storms (incl.cyclones, hurricanes and typhoons)
	Extreme temperatures
	Storm surges
	Droughts
	Wild fires

Figure 1.2 Types of natural hazards that are experienced globally

Table 1.1 shows the average yearly occurrence, impact and death rate associated with disasters that have occurred between 2000 and 2005. The figures suggest that disasters are not rare events but that they actually occur relatively frequently (on average more than one disaster per day) and affect a significant proportion of the world’s population. Floods and wind storms are the most prevalent events, droughts and floods affect the most people on average, while earthquakes and tsunamis/storm surges on average cause the most fatalities. These figures are important because, to paraphrase a popular saying, ‘natural hazards don’t kill people, unsafe buildings do’.⁵ It is therefore clear that future construction practice needs to be more sensitive to mitigate the impacts of a wide range of hazards. This needs to be achieved through proactive measures. These proactive measures are likely to have a bearing on the professional training (formal and informal) and day-to-day activities of a vast range of construction professionals.

Table 1.1 Average annual occurrence and impact of disasters globally, 2000–5

Are ‘natural disasters’ really that natural?

The human influences upon the causes of disasters are too often overlooked because sometimes these influences can be discrete and driven by very different socio-economic factors. For example, in many high-income countries, people like to live near rivers (and are prepared to pay for the benefit in many cases), for the aesthetic and recreational benefits that rivers can offer. For example, upstream, along the non-tidal stretch of the River Thames in England, some 12,000 houses are within 500 metres of the riverbank, and their riverside location adds £580m (approximately £48,000 per house) to the value of these properties (McGlade 2002). Therefore, a flood event that occurs in the non-tidal stretch of the River Thames, inundating people’s homes, businesses and lifelines will typically be referred to as a ‘natural disaster’ but the flood event manifests itself as a disaster because society (and this is predominantly the case in high-income societies) has chosen to build homes, infrastructure and businesses in an area vulnerable to floods.

Socio-economic factors that affect people’s exposure to hazards can manifest themselves differently in low-income nations, with key factors being related to poverty (low access to assets), marginalisation (poor access to public facilities) and powerlessness (low access to political and social networks) (Bosher 2007). These factors will have an influence on the choices that people have regarding where they can live (for instance the landless squatters that live on the flood plain of the Buriganga River in Dhaka, Bangladesh and the informal slums (favelas) situated on the steep landslide-prone hills of Rio de Janeiro in Brazil). These factors will also influence the levels to which people can provide themselves with adequate shelter to protect themselves from local conditions; therefore geographic proximity and exposure to hazards will affect levels of individual and social resilience (Wisner et al. 2004). Consequently, unlike the case of higher-income nations where many people choose to live in areas that are exposed to hazards, in low-income countries it is more the case of a ‘lack of choice’ that forces people to live in areas that are exposed to hazards.

Another human aspect that influences the prevalence of disasters is related to how the built environment is planned, designed, built, maintained and operated. Urban areas that are constructed (whether formally or informally) without due regard for natural and human induced hazards are unlikely to provide the levels of resilience that are required to ensure settlements are safe and sustainable. This concern is related not merely to residential properties but also associated infrastructure and institutional/governmental and commercial built assets and is a problem that will be discussed in more depth in the forthcoming chapters.

It is therefore pertinent, if not somewhat contentious and provocative, to suggest that ‘natural disasters’ are actually quite rare occurrences⁶ and that most of the events that are labelled as ‘natural disasters’ are actually a combination of natural and human induced events.⁷ To help clarify and illustrate the point it would be worthwhile considering the following examples:

• Carlisle, in northern England, was flooded in 2005 because it is located on a flood plain and historical attempts to restrict development on the flood plain had achieved limited success. The fact that many critical support services (such as the city council offices including the emergency planning department, plus the police station, the fire station and the electricity substation) were located on the flood plain and therefore severely affected, exacerbated the impact of the floods by impeding the ability of the city to cope with, and recover from, the event.
• New Orleans, USA, was devastated by Hurricane Katrina in August 2005 because it is located in a hurricane zone, situated on land that is largely below sea level and was protected by substandard and under-maintained flood defences. The US Army Corps of Engineers admitted that faulty design specifications, incomplete sections and substandard construction of levee segments, not the hurricane, was the primary cause of the f...

Table of contents

• Cover Page
• Title Page
• Copyright Page
• List of figures
• List of tables
• About the editor
• List of contributors
• Preface
• PART I Introduction
• PART II Structural adaptation
• PART III Non-structural adaptation
• PART IV Conclusions