1998 Year of the Ocean Mitigating the Impacts of Coastal Hazards 



INTRODUCTION 



Coastal Hazards — ^Increasing Populations and Higher Costs 



Destructive natural system events that impact coastal areas can be either episodic or 

 chronic. Together, these types of events define what is meant by natural coastal hazards. The 

 destructive potential of such events is often made much worse by the increasing amount of 

 development along the nation's coastline. 



A variety of natural hazards regularly threaten the nation's coastal inhabitants. Severe 

 meteorological events such as hurricanes, tropical cyclones, and nor' casters are particularly harsh 

 on coastal areas, often resulting in damages from high winds, storm surge, flooding, and 

 shoreline erosion. Tsunamis, whose destructive force is characterized by potentially devastating 

 flood inundation, are uniquely coastal events resulting from offshore earthquakes, landslides, or 

 volcanic activity. Coastal locations are also subjected to the impacts of long-term hazards such as 

 chronic coastal erosion, potential sea-level rise, and global climate change. Other hazards 

 impacting coastal areas include biological events such as red tides and harmful algal blooms. 



Coastal hazard events can significantly affect or even alter the natural envirormient, but 

 their impacts are generally not considered to be "disastrous" unless they involve damages to 

 human populations and infrastructure. Many of the coastal ecosystems that are particularly 

 fragile and sensitive to the cumulative impacts of human development are also naturally fluid and 

 generally capable of adapting to hazard impacts over time. When people and property are not 

 present, hazards are merely natural processes that alter the environment as they have throughout 

 the earth's history. When people and property are present, however, the impacts of hazards on 

 the developed and natural environments are viewed quite differently. The primary focus no 

 longer is on the natural processes associated with a major hazard event, but instead on the 

 disastrous results that can be measured by lives lost, property damages, and economic and 

 environmental impacts. Hazard impacts on the natural environment become more devastating 

 because human development has altered the ability of natural systems to recover from such 

 events. Natural hazard events can also spawn secondary hazards such as sewage releases or 

 hazardous materials spills that are particularly damaging to coastal environments. 



The impacts of natural hazards are becoming increasingly costly and devastating. Experts 

 believe that the statistics on disaster losses continue to rise worldwide due to a combination of 

 factors that include a rise in the number of hazard events due to global climate change or natural 

 cyclical trends, and an increase in human exposure in hazardous locations. Some of the increase 

 in disaster damages worldwide could also be the resuh of improvements in disaster monitoring 

 and reporting capabiUties, particularly in developing countries. Worldwide, all three factors may 

 come into play, but disaster loss increases in the United States seem to be most closely tied to 

 increased human exposure in high risk areas such as the nation's coasts. 



Growth trends in coastal areas have the obvious consequences of increasing human 

 exposure to natural hazards. The . United States has an expansive and diverse coastline that 



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