Voices: Should science dictate whether to rebuild after a natural disaster?

by John C. Mutter
Friday, January 20, 2012

Move Port-au-Prince? Maybe. San Francisco and New Orleans? Never.

It is common for scientists to call for the relocation of a city to a safer location after it is struck by an earthquake or hurricane. After all, when many cities were built, the nature of the hazard they faced was either unknown or very poorly understood. This is true whether we’re talking about San Francisco, Calif., New Orleans, La., or Port-au-Prince, Haiti. Now that we know the hazards, is it time to relocate a city in a dangerous locale? Port-au-Prince? Yes. San Francisco and New Orleans? No.

There had been earthquakes before 1906 in the San Francisco area, but they occurred when few people lived there, before the advent of modern seismic monitoring, and at a time when the science of seismology was new, so the nature of the hazard was not well-understood. Besides, even if there had been a decision to move the city, where should it have been moved? No one then appreciated the distribution of risk the way we do now, so relocation could have been a deadly error. The city could have been moved to somewhere equally or even more dangerous.

Today we know a great deal about earthquake hazard in California, but no one recommends that we move any of the cities that face high risk. Instead, we use engineering to make the buildings and infrastructure as safe as possible so that the people of California are reasonably protected. No doubt a large earthquake would cause considerable fatalities and large financial losses, but it seems very unlikely we would see the number of deaths and amount of destruction that occurred in Haiti in January.

When discussing whether to move a community, the guiding principle must always be the protection of the greatest number of people, while respecting their rights. If moving people affords the best or only viable measure of protection, then it should be considered. But sensible as it may seem when viewed by scientists from a distance, it is far from simple in practice and could be deeply divisive. For example, we can build proper protections in San Francisco and New Orleans. This may not be possible in Haiti.

Given the earthquake hazard in Haiti, a serious relocation study should be undertaken as soon as possible to evaluate the feasibility and desirability of moving people out of Port-au-Prince.

The case for moving Port-au-Prince

The earthquake that struck Haiti on Jan. 12 caused astounding losses, especially in the capital. If the death toll is truly more than 200,000 (it will never be accurately known), it is off the scale for an earthquake with a magnitude of 7.0. California has experienced a number of earthquakes of about that magnitude, and total deaths have amounted to a few hundred. Even the magnitude-7.9 earthquake in Sichuan, China, in 2008 took “only” 68,000 lives.

There is no mystery about the origin of such vast human losses in Haiti. So many buildings were poorly constructed because building codes and the institutions of code enforcement were lacking. But more than that, the true cause of Haiti’s losses is Haiti’s poverty. People build as cheaply as they can because they have no other choice. And cheap is usually dangerous. Although homes of wealthy people and even the presidential palace were damaged as well, overwhelmingly, those who have suffered most — as always — are the very poorest people. And Haiti’s poverty is profound and not diminishing.

The primary case for moving Port-au-Prince, a metropolitan area with 3 million inhabitants — roughly a third of Haiti’s population — is that the seismic risk in Port-au-Prince in particular has not decreased, and may in fact have increased, putting even more people in danger.

Stress transfer calculations from seismologists at the U.S. Geological Survey and elsewhere suggest that in releasing stress in the region of the hypocenter on the Enriquillo-Plantain Garden Fault, the fault system actually increased stress to the west and east, with the greatest increase in the immediate vicinity of Port-au-Prince. Thus the chances of a repeat of the Jan. 12 earthquake in the relatively near future are thought to be significant, and the chances of a lesser magnitude, though potentially very damaging earthquake, are thought to be alarmingly high.

Even with a massive influx of international support and all the best planning and intentions, it is very hard to imagine Port-au-Prince being rebuilt fast enough and in such a way that its people would be protected from another quake.

There are, however, areas of Haiti that are less seismically risky than Port-au-Prince. Between the Enriquillo-Plantain Garden Fault, which essentially defines the southern boundary of Haiti, and the Septentrional Fault that runs across the top of the island of Hispaniola, there is a region of relatively low historic seismicity. The two faults take up most of the plate motion and exhibit the greatest seismicity. So somewhere between these two faults is a better location than Port-au-Prince. Even just about 30 kilometers to the north would put many people at much reduced risk.

Saint Marc and Gonaives, for example, are reasonably sized coastal cities (160,000 and 100,000) with modest port facilities that could be developed. Both are geographically more central to the country than Port-au-Prince. Gonaives suffered flooding and large losses in recent hurricanes, but flood control can be achieved by well-known engineering approaches, and certainly, Gonaives has no greater hurricane risk than Port-au-Prince.

Why not just do it?

There is nothing simple about moving a large population of people to a new location; there is very little precedent, and it raises many questions.

First, even in the wake of disaster, people generally do not voluntarily move from places where they have settled, despite the risks. Coastal regions facing repeated hurricanes are often densely populated because the advantages of living there outweigh the associated problems.

Haitians living in Port-au-Prince will probably not want to move, and news reports suggest that those who were initially displaced into the countryside already want to move back to the capital. The desire to stay is understandable. Not only is moving expensive (and thus prohibitive for most Haitians), but these people have built homes, businesses and lives in their community. Furthermore, many probably came to Port-au-Prince in the first place to find jobs, so theoretically, they still have jobs there. Establishing a new place for the people of Port-au-Prince means creating employment for them at a new location, something that has historically proven very difficult in Haiti.

Secondly, not all of Port-au-Prince was destroyed. Some businesses have already reopened. Can they be forcibly closed and required to move? Incentives could work — for example, by subsidizing relocation costs but not the cost of rebuilding. Or the government could build a modern port facility and airport at the new location, and businesses could be given tax and other incentives to relocate. If businesses moved, people might follow.

But if the people don’t want to relocate, there are no laws that can be used to require it. In theory, the government could claim ownership of all the property in Port-au-Prince and forbid redevelopment. In theory, the government could prevent people from rebuilding. But if the government couldn’t prevent squatters from building shantytowns and could not enforce any building codes in the first place, this will not likely work either.

To move 3 million people from Port-au-Prince to another place, build homes for them and provide them with employment, the international community would need to provide the funding and most of the logistics. Embassies would need to move. Just how much it would cost and how long it would take have not been estimated, but both are sure to come out to be extremely large numbers. But then again, rebuilding Port-au-Prince will also cost the international community a lot and take considerable time. And it is not likely to be much safer in the future.

Perhaps what should be considered is moving only essential functions like government agencies — creating a Haitian Brasilia or Canberra (cities in Brazil and Australia that were planned cities designed from the ground-up as administrative capitals) — and then attempting to rebuild structures remaining in Port-au-Prince as safely as possible. Structures that are reasonably earthquake-resistant need not be extremely expensive. This can be done, and needs to be considered, but it would surely divide the community, ensuring some are at less risk while others remain more at risk. .

The case against moving New Orleans

After Hurricanes Katrina and Rita devastated the Gulf Coast in 2005, many people said, “Let’s not rebuild! Take it as a sign that we shouldn’t be living there.” Those people, some of whom are my geosciences colleagues, are wrong.

The primary difference between Port-au-Prince and New Orleans is that, though it may be difficult to imagine how we could protect the poor residents of Port-au-Prince from another significant earthquake and their government has no capacity to take even minimal steps to do so, in New Orleans, we do know how to achieve the necessary level of protection — and the U.S. government has the financial capacity to do so. There is no need to disrupt people’s lives (any more than they have been).

Our government can protect New Orleans without displacement, using storm surge barriers and properly designed and maintained levees that the U.S. Army Corps or private business is quite capable of constructing. The closure of the Mississippi River Gulf Outlet is an important first step toward the necessary level of protection; the Inner Harbor Navigation Canal Surge Barrier is equally important. These straightforward engineering projects (for which there is enormous global experience to draw from) can improve levees and other protective structures. Protections of this sort are in place throughout the country and throughout the world. The Thames Barrier protecting London is just one of numerous examples. And, of course, a rational evacuation plan that recognizes that so many impoverished residents of New Orleans lack vehicles and that the elderly are immobile would save many lives too.

The ethics of the situation

In truth, there is also an ethical issue here. Throughout the United States, from New England to the Midwest to California, many millions of people live in places protected by levees. And we live in even riskier places as well: We have million-dollar homes on the landslide-prone cliffs of Malibu, the hurricane-prone beaches of North Carolina, and the fire-prone forests of Colorado and Southern California, not to mention the million-dollar homes in San Francisco. These are beautiful locations and are the homes of the wealthiest in our country. We are not asking them to move, not seriously anyway. But in places like New Orleans, where some of the poorest people in the United States live, we talk more seriously about not rebuilding.

Scientists often grumble that it makes no sense to allow rebuilding in all such places, but they are rebuilt all the same. It is sometimes said that we should “take advantage” of the fact that Katrina happened as this somehow gives the opportunity to move people, or ensure that they don’t return. We should “be sensible about it for a change,” they say. But if we actually know the risks associated with other places — the Malibus of this world — why shouldn’t we insist that people move out? What gives us the right to insist that the poor residents of New Orleans — or Port-au-Prince for that matter — should not return to the places they were displaced from, while wealthy people are not seriously impeded from moving back into equally risky places and never asked to move, once they are there? Instead, the wealthy obtain insurance to protect their properties and have cars that ensure they can escape when trouble looms.

Hazards of nature transform into disasters for people through human agency. Our role as scientists is to assess the physical risks. The role of government is to use that assessment and protect people’s right to safe lives and secure livelihoods by ensuring that disasters seldom if ever occur, despite the evident physical threats. If sovereign states are unable to fulfill that role, the international community becomes the duty bearer. That is the case today in Haiti. For the residents of Port-au-Prince perhaps it may be necessary to relocate to ensure they are protected, and the international community may need to help. In New Orleans and San Francisco, protection can be provided by the state without displacing people. And that’s what should be done.