Planning Lessons from the Indian Ocean Tsunami Disaster

Jim Schwab, AICP

It may be months, even years, before all the planning lessons available from the recent tsunami disaster in the Indian Ocean can be fully discerned and digested. It will surely take months, perhaps years, for the communities affected to recover — to find all the bodies, to clean up the local water supply, to remove the debris, to even begin to feel whole again. Slowly but surely, however, most will plan to rebuild, to replace lost housing and facilities, more often than not with outside assistance. As that process unfolds, it is important that some basic lessons from the tsunami, as they become available, be disseminated and taken into consideration, so that the communities can grow back stronger, more sustainable, and more disaster-resistant for the benefit of all. It is also important that the nations not directly affected, but facing potential tsunami disasters, learn from the event as much as they can, and take those lessons home.

Some lessons from the tsunami may take a while to unfold. But it is at least possible to identify some broad categories within which there are clear types of lessons lying on the surface, and there is much we already know about tsunamis from prior research. Once the process of reconstruction takes hold, it will be important to apply those lessons from the outset in managing the process, and in sharing those lessons with the residents of the devastated coastal communities. The most important lessons would seem to fall into five main categories:

Warning Systems

Years ago, the nations surrounding the Pacific Rim installed warning systems that detect deep-water movement of waves caused by seismic disturbances. Pacific islands, before that system was installed, also used to pay a heavy price for lack of adequate warning when tsunamis attacked coastal communities. Experiences like that of Hilo, Hawaii, in 1946, inspired the effort to create the warning system, which uses deep-water buoys to detect the activity, as well as sophisticated communications in the cooperating nations to alert coastal communities to imminent danger. Tsunamis result from fairly short waves traveling at jet speeds across the ocean, sometimes for thousands of miles, whose speed slows but whose height grows, as they move into shallower waters near land. The waves can then tower 20 or 30 feet or more, crushing people and buildings with enormous power. To cross the ocean, however, may take hours, depending on how far the waves travel, and those hours are crucial for alerting potential victims of the impending disaster.

There will always be, however, certain locations that are especially vulnerable even with warning systems in place. The shorelines nearest the offshore seismic disturbance will necessarily have the shortest warning, no matter what, because short distances make for rapid onset of the tsunami, possibly within 15 minutes of the first shock waves. In this case, the shores of the Indonesian island of Sumatra were closest, and the waves reached them in little more than half an hour. Parts of Alaska and Washington are in potentially similar positions. In addition, small remote islands may not afford much higher ground, but most inhabited islands are large enough to contain viable opportunities for evacuation if there is sufficient warning time.

Unfortunately, the system used in the Pacific does not exist in the Indian Ocean, so millions of people were left without warning to suffer the consequences of a tsunami engendered by one of the most powerful earthquakes of modern times. Although poverty was a factor in the failure to install such a warning system, it is also apparent that a lack of regional political cooperation among Indian Ocean nations combined with a serious underestimation of the potential for such a disaster to yield a lack of timely action. (The last major tsunami in the region occurred in 1886.) In the aftermath, disaster officials should use the teachable moment to establish the urgency of never again allowing such an event to occur in that region without an adequate warning system in place. The United Nations and other relief agencies certainly can assist in financing the effort, but the nations that have suffered must also decide that this has become a high priority. The worst-case scenario must never be underestimated again, for it is already clear that the scenario is truly catastrophic.

One complaint from scientists who detected the seismic disturbance early enough to spread the word was that they did not know whom to contact in the governments of the nations affected. The warning system is not merely a matter of detection, but of clear lines of communication internationally, and within the affected nations between national agencies and vulnerable coastal communities. This should include public participation and regularly scheduled safety drills, to make people aware of how best to respond to the next tsunami emergency.

Mapping

Water moves in very predictable ways dictated largely by gravity. It is entirely feasible to map the probable path of a tsunami, just as we already do in a floodplain, and this is preliminary to all other planning. As powerful as a tsunami may be, its wall of water can move inland only as far as gravity and topography will allow before it recedes to the previously existing coastline. Within that area, planners can define a high tsunami hazard zone and delineate appropriate restrictions on the use of the area. The problem is that humans love to build along the shoreline, thus creating the conditions for disaster. Mapping the path of a tsunami allows planners to identify the structures and land areas that are likely to be affected by a tsunami, so that appropriate adjustments can be made in existing development patterns, and so that it is clear where people must move in order to get out of the way. Then, with warning systems in place, the vast majority of people can be spared death or injury.

At the same time, planners must approach the task with humility. Nature can carve out new features in the landscape that did not exist before the tsunami. Some of these, as well as structures built by humans and the sheer devastation wrought by the tsunami, may create public health hazards with pooled, dirty water that can pose major challenges to rescue workers and medical professionals. The power of the tsunami can literally change the map of a coastal area in an instant.

Building Codes

Building codes that take tsunami hazards into account already exist and are in use in the city and county of Honolulu, Hawaii. The Federal Emergency Management Agency's Coastal Engineering Manual also contains provisions for addressing tsunami hazards. Such regulations will typically be more difficult to establish and enforce in poorer nations, but even incremental improvements may save thousands of lives and reduce property losses. In 2001, the National Tsunami Hazard Mitigation Program produced Designing for Tsunamis: Seven Principles for Planning and Designing for Tsunami Hazards, an eminently practical and usable guide for planners and their communities to address this very problem.¹ One of the seven principles relates to building design. In addition to advising against constructing new buildings in high tsunami hazard areas, the guide suggests means of building appropriately where construction is necessary or unavoidable, including requiring buildings to be elevated above the expected high-water elevation. The space below need not be useless: It can house parking, recreational areas, or other uses that are easy to abandon in the face of danger. Much of the damage in a tsunami results from a wall of water smashing into ground-level structures with no way for the water to pass beneath them.

There will inevitably be differences between what is workable in an advanced code in developed nations and the on-the-ground situation in coastal communities in many of the Indian Ocean nations. Nonetheless, many design principles are highly adaptable, and the current disaster aftermath presents an opportunity for all the nations involved to learn from one another in highly practical ways.

Urban Design for Tsunami Hazards

It is possible and wise to limit building within the high hazard zones. Indeed, much of the redesign of waterfront land uses in Hilo described in Designing for Tsunamis is a deliberate attempt to relocate buildings and people beyond the reach of water from an advancing tsunami. Designing for Tsunamis devotes considerable attention to land-use and site planning issues. The use of shore lands can be redirected to more passive uses without losing, and quite possibly while advancing, many of the community's aesthetic goals for such areas. It is far better, less expensive, and less dangerous to lose temporarily the use of a waterfront promenade or park than to watch the destruction of a multistory waterfront hotel or rows of housing. The structures that need to be in the path of a potential tsunami should be those the community can most afford to lose rather than its most valuable real estate. Moreover, communities can build into the aesthetic appeal of its oceanfront lands protections against the tsunami that may mitigate greater damage further inland, such as the tsunami forests in Hilo that stand between the coast and major urban buildings.

Evacuation

The undeniable preliminary requirement to successful evacuation is timely warning. There is more, however, for masses of people can still be trapped amid danger if there is no adequate means to move them away from the shore. In most cases, they need not go all that far. Tsunamis rarely carry water inland more than a few hundred feet, and moving people even a half-mile inland will almost invariably save all but a few lives, and would surely have done so in most of the Indian Ocean communities. The few more difficult cases would have been the heavily populated resort and other islands that afforded less protection and fewer means of escape from the advancing water. But even those might have been substantially evacuated, or people moved to higher floors of hotels, with adequate warning. The important lesson, which accompanies the point about mapping, is that governments must be prepared to identify and activate routes of escape that can accommodate the population inhabiting a vulnerable area. Given the short distances that would typically provide adequate evacuation in all but isolated island communities, many people with adequate warning might well be able to escape on foot, since most people, even children, can hike a half-mile within 15 minutes or less. The more troublesome aspect of evacuation usually involves more vulnerable populations, such as the elderly and disabled, which local authorities must be trained to identify and move safely.

Conclusion

Although it is clear that the lack of a warning system in the Indian Ocean is a gross inadequacy that must be remedied, most coastal communities in the U.S. and other Pacific Ocean countries are far from having done all that is needed to reduce their own vulnerabilities through better design and land-use regulations. The occurrence of a major geologic disaster striking Pacific Rim nations is just a matter of time. The Seattle Post-Intelligencer, for example, noted on December 29 the discovery in 1994 of Brian Atwater, a U.S. Geological Survey geologist at the University of Washington that a massive quake in January 1700 "caused the Washington coast to drop suddenly by five or more feet—and sent a gigantic wave of water all the way to Japan." The Cascadia Subduction Zone is, in effect, similar to the collision of tectonic plates off the coast of Sumatra that triggered the recent disaster. The Pacific Rim is littered with ticking geological time bombs.

How many U.S. communities are adequately prepared for such a disaster? The National Oceanic and Atmospheric Administration (NOAA) maintains a website on this very issue, listing tsunami-ready communities in the five Pacific states–Hawaii, Alaska, Washington, Oregon, and California. The NOAA website also details other NOAA responses with regard to the Indian Ocean tsunami

The Atlantic shores, however, are also not free of tsunami hazards. As recently as 1929, a major tsunami resulting from the Laurentian Slope earthquake, occurring along the southern edge of the Grand Banks, killed 27 people in Newfoundland, Canada. Probabilities for the Atlantic region are considerably lower than in the Pacific, but they do exist.

The next tsunami is not a matter of if, but when.

Jim Schwab is a senior research associate in APA's Research Department.

Notes

1. It should be noted here that Designing for Tsunamis: Background Papers states that the Honolulu code does not fully meet the standards prescribed in FEMA's Coastal Engineering Manual.

Resources

Past APA Research on Natural Hazards

The American Planning Association has a long history of significant research and advocacy on issues of preparedness and mitigation for natural disasters. The links below provide an inventory of much of that work, including PAS Reports, training courses, and other materials accessible currently on APA's website.

Training Courses

"Planning for a Disaster-Resistant Community"

International Work:

In 2000-2001, APA developed training materials, including a two-day workshop, manual, video, DVD, and online resources for use in the Caribbean and Central America following the devastation of Hurricanes Mitch and Georges in the fall of 1998. This project was underwritten by the U.S. Department of Housing and Urban Development and is available bilingually.

"Fundamentals of Site Planning" (English version)

"Fundamentos de Planificación de Sitios" (Spanish version)

PAS Reports

For the following publications, please link to the Planners Book Service for ordering information.

466. Planning for Hillside Development. Robert B. Olshansky. 1996.

473. Subdivision Design in Flood Hazard Areas. Marya Morris, 1997.

483/484. Planning for Post-Disaster Recovery and Reconstruction. Jim Schwab, et al. 1998.

Forthcoming:

Planning for Wildfires. Jim Schwab and Stuart Meck. 2005.

Planning for Landslide Hazards

Statutory Studies

Summary of State Land Use Planning Laws

The New York Times has published a list of agencies assisting the survivors of the quake disaster. The list can be found at www.nytimes.com/international.

Agencies Accepting Aid Dollars

Fllowing are some of the agencies accepting contributions for aid to people affected by the earthquake and tsunami in Asia.