Sunday, 18 May 2008

Lessons in Disaster Preparedness: Vox clamantis in deserto persico

The following was written in early 2004 and remains pertinent in the light of subsequent earthquake disasters.

Introduction: a little elementary geology

As I write this I have in front of me a high-definition satellite image of the Bam area of southern Iran. The signs of recent, cataclysmic tectonic activity emerge spectacularly from the desert landscape. Faults, folds and eroded geological structures are all precisely etched in the arid terrains of the Bam basin. The moderate-power earthquake of 26 December 2003 was an episode of slip-faulting in the normal direction (i.e. vertically downwards). As the dominant fault of the area is transcurrent (i.e. subject to horizontal movement), it seems that the December event was a mere tectonic adjustment to more serious local movements of the Earth's upper crust. Yet tens of thousands of people died in it. More than a geological calamity, the event is thus a terrible indictment of human negligence.

Whatever political expedient may eventually turn them into, natural disasters start as morally neutral phenomena. Hence they are relentless in the way they expose the inner workings of society. The Bam earthquake seems to have revealed a shocking lack of preparedness in Iran.

It is always important to learn lessons for public safety from disasters when they occur, and hence the following are a brief series of reflections on what lessons the Iranian case has to offer.

The timing of events

The Bam earthquake happened at 05.27 local time. At the world scale, whereas the distribution of damaging earthquakes is exactly balanced between the three periods 8 am-4 pm, 4 pm-midnight and midnight-8 am, 80-95 per cent of casualties occur in the last of these periods. This is firstly because vernacular housing in many of the major seismic zones is the least safe place to be, and secondly because people cannot take self-preserving action when they are asleep. Behavioural research suggests that people's instantaneous reactions to the onset of major seismic shaking can have a very significant impact in reducing the death toll. Even so, the average number of people killed per building that collapses is only somewhere in the range 0.12-0.34, though in the Bam case the buildings were so weak and collapsed so readily that the final ratio is likely to be anomalously high. Nevertheless, in Bam the unsafeness of vernacular housing was graphically demonstrated: 60-70 per cent of it collapsed, with heavy loss of life.

The usual myths

This morning the television newsreader on Italian Channel 5 spoke solemnly of the high risk of epidemics caused by unburied dead bodies. His report was backed up by pictures of corpses being flung by the dozen into long, shallow trenches over which the dusty earth was hastily bulldozed. Meanwhile, piles of dead bodies were being sprayed with disinfectant, and so were survivors, rescue workers and collapsed buildings.

At least, as southern Iran is a desert area, the trenches will not flood and the bodies will not float out of them before they can be covered with earth, as has happened so often elsewhere. Time and time again, eminent and authoritative experts have pointed out that dead bodies do not constitute a health hazard. Indiscriminate burial demoralises the survivors and can lead them to be deprived of transferable pension benefits through failure to provide death certificates for pension-holders. Spraying wastes useful disinfectant, as well as manpower.

The Bam earthquake happened 18 months after the last mass-casualty seismic event in Iran, yet even the arrangements for disposing of the dead were utterly ineffective. Then there was the vexed question of looting.

Reuters reported that armed men stole Red Crescent tents and others on motorbikes chased trucks that were tossing out blankets to the survivors. Studies reveal that looting is a highly uncommon and circumscribed phenomenon in the aftermath of natural disasters, which are usually characterised by high levels of social participation. The Reuters report from Bam did not give any indication of its magnitude, which was probably small. Nor was there any indication of the social conditions that led to it (brigandage is endemic in the Bam area).

Neither is it very likely that the fabric of society stood any chance of disintegrating into chaos, another cherished myth. However, if nothing else, the image of blankets being tossed indiscriminately from the back of trucks implies a serious failure of relief distribution mechanisms.

International efforts

Along come the international search-and-rescue teams. No one would wish to belittle their efforts, and if one person is saved by their presence, then that would be a significant achievement. However, there were two reasons why in the Bam case the presence of international rescuers was even less effective than usual (apparently they saved 30 people during 48 hours' work). First, the local building materials (stone with little shearing resistance, poorly-fired brick and mudbrick) produced more dust than is commonly the case and hence both reduced the size of void spaces in rubble that might contain living, trapped victims and contributed to asphyxiation through dust inhalation. Generally, suffocation is much more effective at reducing survival times under rubble than are major blood loss, cranial trauma, hypothermia and dehydration. Secondly, the weather was cold. Within 100 hours of the earthquake, hypothermia would halve survival rates among trapped people.

There is now a huge amount of evidence, accumulated from natural disasters all over the world, that it is local aid that rescues people in significant numbers, and in sudden impact disasters the critical period can be as short as six hours. During this interval the degree of training and appropriateness of equipment of local rescuers will determine the efficiency of search-and-rescue operations.

Hence, a massive, expensive international rescue operation was launched to bring dead bodies out from collapsed buildings, something that could be done just as well with national resources. It probably will not function well, as the key to body retrieval is heavy plant, which is not supplied internationally.

National efforts

Even national aid is bound to be less effective than local efforts. Huge increases in the numbers of blood donors were reported from Tehran, resulting, no doubt, in a massive temporary surplus in available blood supplies in the Iranian medical system. This would not do much to help the survivors, as injuries that require major transfusion are seldom that numerous in earthquakes. Given the prevalence of crush syndrome in major earthquakes, kidney dialysis is much more important. Apart from that, pre-hospital treatment is the greatest key to survival, especially where crush syndrome is involved, and that once again highlights the importance of local efforts.

Local medical efforts were of course hampered by the collapse of two hospitals, echoing similar losses in, for example, the 2001 El Salvador earthquake. The decision to airlift 11,500 patients to medical facilities in other parts of the country is thus understandable--the local hospitals would have been overwhelmed even if they had survived. But as it involved a logistically cumbersome, medically risky, time-consuming and expensive exercise, it could hardly be described as the soul of efficiency.

Preparedness and planning

News reports from Bam contained graphic descriptions of improvisation and chaos in the relief efforts. All too often emergency planning is either unsystematic or totally absent. Yet there is very little in a natural disaster and its aftermath that cannot be foreseen by the systematic application of scenario methods and the use of reference events from the past. Iran has an unusually rich stock of the latter: so has Kerman Province, in which Bam is located, as it experiences a major earthquake about once every 8.7 years, surely such a short interval that there is no excuse for not having effective plans.

When disaster occurs, failure to plan in advance is suddenly, and often spectacularly, revealed as ineptness in the provision of relief and aid. By and large, not enough is being done to promote robust methods of emergency planning around the world. The need is obvious, the techniques are tried and tested, but the stumbling block is the matter of how to convince political hierarchies to devote a proportion of national wealth to such initiatives.


There is no technical reason why at least 90 per cent of what has been knocked down should not be elegantly rebuilt, and to reasonably anti-seismic standards. It is purely a matter of economics and organisation. As the International Council on Monuments and Sites says, there is no technical reason why ancient buildings, including mud-brick ones, need collapse in earthquakes, as the know-how to render them safe has existed for decades (and in some cases centuries).

And so...

Paradoxically, earthquakes have the power to make the world a better place by encouraging the virtues of prudence, preparedness and organisation in the human populations of seismic areas. But is that what happens? The usual welter of accusations and criticisms began in the Iranian press the day after the earthquake. In itself this is not a bad sign, but will it lead to constructive changes or will the lessons be forgotten before they can be applied?

More than ever before we can say that the scientific know-how is there, the planning techniques, engineering methods and expertise are available. Perhaps it is time to devote a substantial proportion of our considerable research expertise in the disasters field to determining why obvious lessons are being ignored at the expense of future public safety.