Vulnerability, Risks, and Hazards

Hazards

Hazards represent threats of potential damage or destruction to individuals and society. The actual hazard event, such as a flood, earthquake, wildfire, blizzard, or nuclear reactor accident, may result in a disaster if the incident results in substantial human disruption, whether measured by property damage, injury, or loss of life. An event must have the potential to be sufficiently disruptive of human activities to be considered a hazard, thus the physical magnitude of the event that is considered a hazard varies geographically and temporally. For example, several centimeters of winter snow would be considered routine in the northern Midwest, while it would pose a significant hazard in Southern Florida. Likewise, routine moderate precipitation is not considered a hazard but a valuable resource. However, too little or too much rain results in drought and flood hazards, respectively. Indeed, hazards are sometimes termed negative resources.

Geographic study of natural hazards grew out of the pioneering work of Gilbert White, nearly three quarters of a century ago, dealing with river flooding. Because flood losses were increasing even though substantial investments had been made in the construction of dams and levees, White saw the need to fully explore how human activity was related to flooding. To appropriately understand flood hazards, the complex interrelationships between the natural environmental systems that led to flooding and the web of human activity that resulted in lives and property being placed at risk needed to be thoroughly understood.

Natural and Technological Hazards

Building on these studies of flood hazards, the hazards field expanded to include not only a wide variety of geological, hydrological, and meteorological events but also many technological hazards, including those related to industrial and transportation accidents, releases of toxic chemicals and radiation, and pollution. At the same time, the study of hazards spread from American or European settings to less industrialized non-Western societies—although such studies remain in the minority. Hazards related to global warming are increasingly being considered, and studies have considered the consequences of such warming on drought, wildfire, and hurricane hazards, among other hazard threats. Furthermore, growing world populations have led to both overgrazing and deforestation, both events that may increase the likelihood of flood, drought, and landslide hazards. Thus, hazards may have either natural or human causes.

Recent research has included Natech hazards, those in which natural hazard events trigger technological disasters. Natech hazards include events such as flooding or seismic activity that spills toxic chemicals. The definition has expanded to include disruption of critical infrastructure, such as water supply lines, electrical transmission systems, or transportation networks, resulting from natural hazards.

Geographers have also studied the risk and distribution of various diseases from a hazards perspective, yet diseases and pollution have often been studied from other perspectives. Furthermore, geographic study and teaching about hazards often excludes disease and pollution hazards. While Ken Hewitt has proposed the geographic study of hazards of war, and others have studied terrorism hazards, these topics are ignored by the majority of hazards geographers. Nevertheless, urban violence, poverty, and street crime can all be studied from a hazards perspective.

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