ENVIRONMENTAL PLANNING

Environmental Planning

Environmental Planning

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 bodily 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 damaging resources (Blaikie & Davis, 2004).

Building on these studies of flood hazards, the hazards field expanded to include not only a wide variety of geological, hydrology 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 remains 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 physical causes.

Geographic study has tended to concentrate on the hazard itself, or the spatial patterns of disaster, while societal response and disruptions resulting from disasters are typically studied by sociologists. In studying hazards, geographers consider both the physical event and the human response or adjustment to it, as it is the complex interactions of the physical and human systems that create and determine the intensity of the hazard. Changes in technology, human occupancy, and timing provide the context that can either accentuate or ameliorate hazards. While some geographers have emphasized hazards resulting from specific physical threats, others have focused on human responses, including perception, hazard mapping, land use planning, evacuation, and reconstruction, among other mitigation topics.

Risks

Risks have been loosely described as environmental threats, but risk can be viewed as a function of hazard and vulnerability. Risk is defined as a measurement of the probability of experiencing an extreme event or an event of a certain magnitude. Although the public misconstrues probability information, much geographic study of and societal response to floods have dealt with the concept of the 100-year flood, or a flood with a 1% probability of occurrence in any given year (Hewitt, 1997). Flood Insurance Rate Maps display those areas of the United States with this flood risk, in which flood insurance and land use regulation are ...