The Human Factor
Most hurricanes kill and destroy with a surge of seawater. Not Hurricane Andrewthe monster of 1992a storm that led to at least fifty deaths and more than $30 billion in property damage in southern Florida. Sufficient warning enabled people to evacuate from dangerous beaches even as the worst of the storm miraculously skirted downtown Miami. But Andrew pummeled south Florida with particularly intense air currents that leveled well-built homes and demolished Homestead Air Force Base. The damage from the winds was more severe than expected, given that the region's building codes had been considered among the best in the country. As it turned out, however, enforcement of those codes had grown lax during the region's recent building boom.
All the science-based predictions and warnings in the world will not mitigate a natural disaster made more devastating by human folly. Ironically, improved hazard warnings in the U.S. may be one of the factors encouraging more and more people to move to homes on the earthquake- and hurricane-prone coasts. As noted in a 1999 report by the National Research Council's Board on Natural Disasters, 80 percent of Florida's population now lives within 22 miles of the beacha fivefold increase since 1950. A steady rise in the migration to cities has also made more people more vulnerable to the effects of natural disasters as they live amidst aging infrastructures increasingly susceptible to the slightest ill wind or tremor. Urban growth also translates into more pavement and less exposed soil, which forces rain to run off rather than soak into the ground and tends to increase flood damage. All this means that the sharply upward trend in the costs of natural disasters is attributable not so much to the occurrence of more hazards but rather to human choices that place more of our structures and possessions at risk.
Sometimes, too, steps taken with the best of intentions to limit the dangers of natural hazards can turn out to amplify the problem. The intense rains and flooding that occurred in 1993 along the Mississippi River provide an example. The levees and dikes that had been built along the river to protect communities from the occasional mid-level flood allowed more development in the area and also effectively eliminated the flood plain, exacerbating the damage caused by the unusually massive surge of water in 1993.
"Disasters by Design: A Reassessment of Natural Hazards in the United States," a five-year-long NSF-funded study, was released in the spring of 1999. The study compiled the thoughts of 132 experts on how communities can better prepare themselves by evaluating potential local threats up to 200 years in the future, determining acceptable losses, and then planning for them.
Says study leader Dennis Mileti of the University of Colorado's Natural Hazards Research and Applications Information Center, "We need to change the culture to think about designing communities for our great-grandchildren's children's children."