Facts of the Matter
Facts of the Matter
Natural dangers make
total safety difficultThere is no question that natural events can cause both tragedy and trauma, but it is us and not Mother Nature that is out of place. We tend to see ourselves as occupying a special place in nature, while nature has no partiality for us. Nature does what she does, what she has been doing throughout the earth's long history, long before humans evolved within her bounds. Only when we get in the way of her impartial processes do we call it "disaster."
Rockslides are a type of gravity-driven movement of earth materials that geologists call mass movements. Worldwide there is more loss of life and property from mass movements than from any other type of geologic event, mostly in the form of mudflows and landslides associated with heavy rains and volcanic eruptions.
Not all mass movements are as spectacular. Their scale ranges from the continual and imperceptibly slow downhill creep of surface rocks and soil at a rate of a few inches per century to rapid and catastrophic landslides, slumps, soil avalanches and the rockfalls that have been in our local news recently.
Although mass movements are sometimes disastrous, they are an important and ongoing part of the development of the landscape. The scenic valleys and spectacular cliffs that please our eyes owe their existence to mass movements. How else could a tiny stream cut a valley that is thousands of times its own width, or ocean waves create cliffs hundreds of time higher than the waves themselves? Gravity will ultimately drag the weathered remains of rocks downhill, where streams or waves carry the debris away to be deposited elsewhere.
We can not help but to be exposed to a certain amount of risk from nature, since we can not isolate ourselves from it. Our island lifestyle centers around activities that put us face to face with the hazards of the outdoors, yet much of the injury and death that are attributed to nature result from our own arrogance or lack of awareness of the associated risks and hazards of being outdoors.
Because there is danger in the natural world, it is desirable that we should be protected from nature to some degree. But it is not entirely clear who should be responsible for protecting us, how much we should be protected or who is liable when there is injury to person or property.
On one hand, property owners should bear some responsibility, but on the other hand it is virtually impossible to analyze each and every boulder on every square foot of hillside. On one hand, one cannot reasonably assess every rock on the hillside before we set out our picnic, but on the other hand we should be aware that talus slopes at the base of a cliff are there because rocks accumulate there after tumbling down from above.
Hazard prevention at any level is a balance between cost and risk. Everyone is willing to accept some level of risk, and an acceptable level of risk is built into every civil engineering design.
Problems arise when the level of acceptable risk by engineers or public officials is different than our own, yet complete satisfaction can never be possible because no two people will prioritize risk the same way. In all cases the likelihood of occurrence must be weighed against the severity of danger and the cost of mitigation. For example, no one would favor making a building invincible to earthquakes if it made it too expensive to build it.
Comparatively speaking, the risks of most natural hazards are quite small compared with other, more manageable risk that we choose not to ameliorate. Our priorities are sometimes puzzling.
Smoking, alcohol consumption, inattention to driving, unhealthy diets, unprotected sex and lack of exercise are more risky than living on a hillside, yet attempts to regulate them are met by great opposition while we expect to be protected against the inevitability of rocks rolling downhill. We routinely accept tens of thousands of deaths annually from drunk drivers, yet a handful of deaths or injuries from a natural event such as a rockslide is front-page news.
It is good to see state and private efforts being made to mitigate potential disasters, but within limits and only to the extent that a solution is feasible. No decision concerning how much time and money should be spent will be universally acceptable.
The opinion of one who has been devastated by a disaster that might have been preventable if only a few more dollars had been spent will likely be quite different from one who has not. Although there is no value that can be placed on a life, it just isn't possible to protect against everything that might cause us harm.
Like it or not, there is no way to be 100 percent safe 100 percent of the time, and some things are nobody's fault.
We could all be a little smarter, no? Richard Brill picks up
where your high school science teacher left off. He is a professor of science
at Honolulu Community College, where he teaches earth and physical
science and investigates life and the universe.
He can be contacted by e-mail at rickb@hcc.hawaii.edu