<br><h3> Chapter One </h3> <b>Introduction</b> <p> <p> To clearly understand the essential dimensions of hazards and disasters, it is necessary to introduce basic concepts regarding these extreme events. This chapter is, therefore, devoted to providing both traditional and contemporary definitions of hazards as well as disasters. It will be evident from this and subsequent chapters that human actions play a major role in causing and/or exacerbating the effects of extreme events. The outcomes of such events arise in large part from human conditions and processes that differentially exposed or protect people and either limit or enhance their ability to appropriately respond to and recover from hazardous events or conditions. <p> Since both hazards and disasters are related to many disciplines and professional communities, there are many definitions of these two terms. An attempt will be made to provide definitions from an interdisciplinary perspective, which will help in arriving at a suitable definition of a term accepted by all dealing with extreme events. In most instances, the terms hazards and disasters, as used in this book, refer to natural hazards or disasters. In defining these two terms, a distinction will be made between them because people often use these terms interchangeably. In the hazard literature, however, each term has a precise and distinct meaning. <p> Subsequent to this discussion of definitions, an overview of hazard typologies will then be presented, followed by a discussion of important physical dimensions of natural hazards. Although three important components (definitions and distinctions of hazards and disasters, types of hazards, and physical dimensions of natural hazards) of extreme events are considered in this chapter, emphasis has been given to definitions and distinctions between hazards and disasters. Topics included in this introductory chapter will aid in understanding material presented in subsequent chapters. <p> <p> <b>1.1 Hazards and disasters: definitions and distinctions <p> 1.1.1 Hazards</b> <p> There are many definitions of hazards, but only one definition makes a distinction between hazards and disasters. According to Alexander (2000, p. 7), "a hazard is an extreme geophysical event that is capable of causing a disaster." The word "extreme" is used here to signify a substantial departure (either in the positive or the negative direction) from a mean or a trend. Although Alexander did not specify the distinction between these two terms in his definition, it does suggest that hazards may transform into disasters and thus become sequential events. That is, every disaster starts with a hazard (Thywissen, 2006). Alexander's definition, however, ignores the fact that human actions often play a major role in causing and/or exacerbating the effects of extreme events. Hazards represent the potential occurrence of extreme natural events, or likelihood to cause the severe adverse effects, while disasters result from actual hazard events (Tobin and Montz, 1997). Only after such an extreme event occurs may we term it a "natural disaster." A hazard is a threat not the actual event. <p> One of the earliest definitions of hazards is provided by Burton and Kates (1964) who maintain that natural hazards are those elements of the physical environment that are harmful to humans and caused by forces extraneous to them. That is, these events originated in the physical environment and are not caused by humans, but have consequences harmful to them. Burton and Kates' definition is correct in the sense that hazards are harmful to people, but it fails to recognize people's role in causing or amplifying the impacts associated with hazards. For example, floods can originate either from a natural variability in meteorological conditions or from human actions, such as deforestation, intensive use of land, or failure of dams constructed to control flooding (Haque, 1997). Similarly, landslides are commonly triggered by heavy rainfall (sometimes on hills and mountainsides previously denuded by wildfires), earthquakes, and volcanic eruptions, but also result from human activities such as logging, road building, and home construction, all of which can expose bare soil (Wisner <i>et al.</i>, 2004). <p> There is no doubt that humans affect natural processes in many ways and thus often contribute to hazards. Many physical aspects of natural hazards, however, are out of their control. This does not mean that people are just passive in facing hazards; they can and do construct defenses against and implement measures to mitigate the impacts of hazards. Still, many people, even in the United States, consider natural hazards to be "acts of God" or the result of some external force (Mitchell, 2000, 2003). A careful reading of digital and print media reports covering more recent events, including Cyclone Nargis in Myanmar (May 2, 2008), the outbreaks of tornadoes in the Midwest and Southeast United States (April 29 and early May, 2008, respectively), and the earthquake in China (May 12, 2008) all occurring within a time span of one month, found that these extreme events are typically characterized as acts of God or of Mother Nature that leave human victims in their wake. This perspective suggests – quite wrongly – that people have no role to play in creating/exacerbating disasters, nor in mitigating their impacts (Smith, 2001). This interpretation of natural hazards as acts of divine will or forces of Mother Nature exonerates people from sharing in the responsibility for the creation of such extreme events. <p> According to Cutter (1993), hazards are threats to people and the things they value (such as their homes and belongings and environment). Oliver (2001, p. 2) has provided a similar definition; to him "A hazard is a threat posed to people by the natural environment." In its broadest sense, a hazard reflects a potential threat to humans and their welfare. A hazard is defined by the United Nations as an agent or threat that is "A potentially damaging physical event, phenomenon or human activity that may cause the loss of life or injury, property damage, social and economic disruption or environmental degradation" (UNISDR, 2004). This definition directly acknowledges the role of humans in causing/exacerbating hazards. It also makes the distinction between a hazard and a disaster by including the word "potentially," and it accounts for all possible hazard manifestations. <p> Hazards are also often defined in the context of vulnerability, which is a complex outcome of many factors, such as affluence, education, gender, demography, technology, and, above all, preparedness. Location can also act as a vulnerability factor. African Americans living in New Orleans were the most vulnerable segment of the population impacted by Hurricane Katrina in 2005, not only because they were poor but also because they inhabited (almost exclusively) areas below sea level. Low-income residents simply could not afford housing in areas above sea level. Another example of location as an important factor of vulnerability can be cited from Rio de Janeiro, Brazil. Many of the poor in this city occupy steep hillside locations above the reach of sewer, water, and power lines. Frequent heavy rains saturate the hillside and cause mudslides that destroy their rudimentary shelters. A combination of different factors, such as socio-economic conditions, geographic locations, political influences, and demographic characteristics, shapes the differing levels of vulnerability of different groups of people when an extreme natural event occurs (Wisner <i>et al.</i>, 2004). <p> Chapman (1999, p. 3) argues, <p> A natural hazard should be defined as the interaction between a human community with a certain level of vulnerability and an extreme natural phenomenon, which may be geophysical, atmospheric, or biological in origin, resulting in major human hardship with significant material damage to infrastructure and/or loss of life or disease. <p> <p> He further claims that a particular level or severity of a natural event becomes a hazard only in relation to the capacity of society or individuals to cope with the impacts of such events. In addition to incorporating an ability to cope with the impacts of hazards, this definition also suggests further classification of hazards based on their source or origin. <p> Strategies adopted to cope with hazards can be classified in two different ways: by making a distinction between indigenous and modern coping mechanisms, as well as between those strategies adopted purposefully and those which are incidental. Planting floating rice, which grows with the rise of flood water in lowland areas of rural Bangladesh, is an example of an indigenous coping strategy, while the flood warning system introduced in the early 1990s by the government in this South Asian nation can be considered a modern coping strategy. Further, coping adaptations can be separated into those that are purposefully undertaken and those resulting from incidental actions. Cultivating different rice crops in different elevation zones within the floodplain of Bangladesh is an example of a purposefully undertaken coping strategy, while constructing houses in the floodplain using materials such as thatch and bamboo, which can be readily moved by boats to safer places during abnormal flooding, is an example of incidental action. <p> Since the 1970s, hazards have been increasingly viewed as acts of human agency as well as the potential interaction or conflict between humans and one or more extreme natural events. Natural hazards lie at the interface between the (potential) natural event system and the (potential) human use system (Figure 1.1). Hazards thus exist within social, political, historical, and environmental contexts (Cutter, 2001). Hewitt (1983) and other researchers believe that hazards result more from social than geophysical processes. They eloquently argue that a "natural" hazard is a misleading term, as very little is natural about phenomena in which the danger results largely from human decision-making, land use, and/or socio-economic activities. Traditional explanations tend to emphasize hazards as processes of nature, their wrath inflicted randomly on unfortunate people. Contemporary hazard researchers blame many of the impacts associated with hazards on society and its varied institutions. <p> Hazards exist because humans and/or their activities are usually exposed to natural forces. As noted, we often create/exacerbate hazards, or modify hazard effects. For example, many wildfires are started by humans, either deliberately or unintentionally (Chapman, 1999). Hazards are in part socially constructed by individual perceptions and experiences. Thus, hazards can vary by culture, gender, age, race, socio-economic status, and political structure as well. For example, although the West Nile virus is usually fatal to the elderly, it is not to young adults, who often survive it. Normal flooding, which may inundate up to one-third of the total land area of Bangladesh, is seen by people of this country as a necessary and expected part of life; however, in the United States or most other Western countries, floods are generally seen as hazards. <p> The above example makes an important distinction between hazards and resources and supports the human ecology perspective of natural hazards proposed by Burton <i>et al.</i> (1978). They noted that when a natural event exceeds a threshold point or upper limit, a resource turns into a hazard. In the context of flooding in Bangladesh, 33% of the total land area of the country under water would be considered a threshold point. The specification of a threshold level for a given place or society, however, poses significant problems for hazard researchers. A threshold level for crippling snowfall in Toronto, for example, is much higher than the threshold for Norfolk, Virginia. Similarly, a temperature of 20°C is considered "freezing" in Tonga, but "scorching" in Baffin Island, Canada. <p> Any discussion of hazards must cover several essential attributes of such events. First, extreme natural events that do not affect (harm) people do not constitute a hazard. An earthquake in an uninhabited desert area, for example, cannot be considered a hazard, no matter how strong its intensity or how long its duration. Second, what is considered a hazard in one society may not be considered as such in another. It will be evident from the excerpt (below) from the poem "Floods in Bulozi," by O.K. Sibetta [translated by Charles and Slater (1995)], that floods are not considered hazards in Zambia, but they are in Western countries. Third, a hazard to some is to others a business opportunity or even a joyful experience. Drought is a hazard to farmers, but not to those engaged in construction – they can build houses and repair roads without interruption. Similarly, global climate change is likely to benefit some regions of the world while detrimentally impacting others. <p> <p> <b>Floods in Bulozi (Western Zambia)</b><br> <br> It is floodtime in Bulozi<br> There is the floodplain clothed in<br> the water garment<br> Everywhere there is water!<br> there is brightness!<br> there are some sparkles!<br> Waves marry with the sun's glory<br> Birds fly over the floods slowly,<br> they are drunken with cold air<br> they watch a scene which comes<br> but once a year<br> floods are tasty (nice, beautiful)<br> Bulozi is the floods' place of abode<br> every year the floods pay us a visit.<br> we do not fear floods ...<br> A Lozi does not beg for floods<br> We do not turn the herbs to have floods<br> We do not practice witchcraft whatsoever<br> They are floodwaters indeed!<br> The floods know their home area.<br> Floods are ours<br> the floods themselves<br> they (floods) know their own route<br> they know their home area<br> they know where they're needed<br> they know where they are cared for<br> And when we ourselves see them<br> we are inflated with happiness<br> our hearts become lighter<br> <p> <p> To say that a hazard to some may be a completely different experience for another is a subjective position. Whether or not one perceives driving without a seatbelt as hazardous, it can result in fatalities; whether or not one perceives smoking as a hazard, countless studies show that health is negatively affected by smoking (Mitchell and Cutter, 1997). However, a final attribute is that natural hazards constitute a threat to all societies, and these societies must cope with the hazards they encounter in one way or another. The type of hazards may vary from place to place, but no area is free from extreme natural events. Californians, for example, may not experience hurricanes, but they are vulnerable to earthquakes, mudslides, and wildfires. <p> In defining hazards, some researchers (e.g., Cutter, 2001; Cutter <i>et al.</i>, 2000) advocate inclusion of a technological dimension. They consider hazards on a continuum of potential interactions among physical, social, and technological systems (Montz <i>et al.</i>, 2003). According to them, this dimension is important because technology may affect the extent of damage – particularly the number of deaths. A tropical cyclone in Bangladesh killed more than 500 000 people in November 1970, while Hurricane Agnes along the east coast of the United States caused the deaths of only 12 people in June 1972. Bangladesh introduced a cyclone warning system after the 1970 cyclone. For this reason, not a single person was evacuated from coastal areas prior to the landfall of the 1970 cyclone. In contrast, prior to the landfall of Hurricane Agnes, 250 000 people were evacuated and this evacuation undoubtedly saved many lives. <p> Another example in support of the effect of technology on hazard impacts is the comparison between the 1998 Armenian earthquake and the 1989 Loma Prieta earthquake in California. Despite being of similar magnitude – the Armenian earthquake measured 6.9 on the Richter scale, while the California quake exceeded 6.9 – these two events caused very different numbers of deaths. At least 24 000 people died in Armenia, while the Californian quake killed only 63 people. The difference is often explained in terms of the different levels of technology in Armenia and the United States. <p> It is important to note that hazards are also a consequence of development and industrialization, which are directly associated with technology. In Europe, experts believe that countries such as France and Germany are more adversely affected by floods today because major rivers, such as the Rhine, have been straightened to ease commercial traffic. Interference with the natural flow of river water is thought to increase flood frequency in these countries. In addition, some hazard researchers stress that culture should be identified as an independent component, not a part of the human use system as shown in Figure 1.1. <p> <i>(Continues...)</i> <p> <!-- copyright notice --> <br></pre> <blockquote><hr noshade size='1'><font size='-2'> Excerpted from <b>Environmental Hazards and Disasters</b> by <b>Bimal Kanti Paul</b> Copyright © 2011 by John Wiley & Sons, Ltd. Excerpted by permission of John Wiley & Sons. All rights reserved. No part of this excerpt may be reproduced or reprinted without permission in writing from the publisher.<br>Excerpts are provided by Dial-A-Book Inc. solely for the personal use of visitors to this web site.