Gambling with Nature

Natural disasters are a fickle opponent because there is no completely predictable process or enemy to counter. Instead, we rely upon historical information, intuition, and a sense of risk. Before we can even address good or bad design issues, we can look at how we even choose what level of disaster to design for. A great example is the recent catastrophe in Japan when a large earthquake wrecked some regions, but perhaps the greatest damage came from the resultant tsunami spilling over the sea walls and causing the nuclear reactors to dump radiation onto the surrounding civilians.

Why weren't the sea walls designed to withstand such a tsunami? The answer is in cost/benefit and risk analysis during the designing of the sea wall. Sure, engineers could have designed an impressively robust sea wall that could withstand the entire ocean hurling at it, but such an undertaking would be costly. Engineers must balance the cost of the measure with the benefit of it succeeding. If a disaster causes $5 billion in damage, and there's a 1/1000 change of the disaster occurring, then it makes sense to spend about ($5B/1000) or $5 million dollars to assure that event is mitigated. This damage prediction also includes the loss of life -- and yes, you can place a dollar value on a life; after all, that's what insurance companies do. There is also the matter of risk. Looking at historical data, engineers can extrapolate the likelihood of certain size events. Using that probability curve, they choose an event size to design for. Of course, a larger event may happen that has never occurred previously, and that is a risk that comes with gambling with nature.

A popular area of engineering R&D is in earthquake proof buildings. There are many systems out there, such as the one currently being developed at Stanford to absorb the energy of a building's motion during quakes. Unfortunately, like many other systems, it is not in wide spread use because of the relative youth of these designs, and thus not many buildings are equipped to handle earthquakes. The systems are more common, and necessary, in new skyscrapers where the building can sway even during normal days yet alone during an earthquake. For example, Taipei 101 contains a tuned mass damper to stabilize oscillatory motion in the structure. These sorts of designs and technologies are mitigation techniques being employed prior to the natural disaster to minimize the effects of such disasters.

Some of the worst aspects to natural disaster design is not in a physical design, such as a structure or device, but in the policy and response. We may not think about policy and social regimes as associated with design, but they really are -- there is a lot of engineering and creative thinking involved. These responses also employ technological devices and scientific knowledge which may directly affect the policies or which may aid in executing the response. The key is to find a synergy between engineering and policy. Of course, the solution to this problem can come on several fronts. First, engineering could help to shape the policy response directly, though this is often problematic because of the disconnect between engineers and politicians. Second, engineering solutions can aid in the response through technological means. Emergency communications, rescue vehicles, and other routes can all provide post-disaster relief.

Countering natural disasters entails both a pre-disaster effort to mitigate problems and also a post-disaster effort to recover from problems that were not mitigated. Unfortunately, the later is largely driven by government response which may or may not be dependable in any given situation, but engineering design solutions can certainly aid in the response. As for mitigation, engineering can play a much more active role in strengthening our world against natural threats.