We need to understand why some people act on early warnings while others ignore them, says disaster preparedness specialist Sudhir Kumar.
The Great East Japan Earthquake and subsequent tsunami of 11 March 2011 challenged global ideas about responding to disasters. It showed that structural defences alone, such as breakwaters, coastal dykes and tidal barriers, cannot provide protection from tsunamis of such magnitude.
The events of that day also emphasised the importance of 'end-to-end' early warning systems (systems spanning all steps from hazard detection through to community response). A Japanese government study, published in the Japan Times in August 2011, has found that only 58 per cent of people in coastal areas of Fukushima, Iwate and Miyagi prefectures heeded tsunami warnings immediately after the earthquake and headed for higher ground.
Of those who attempted to evacuate after hearing the warning, just five per cent were caught by the tsunami.
The report's findings raise the question of why some people act on early warnings while others ignore them.
Barriers to action
As climate change alters the risks posed by extreme weather events, how a community responds to early warnings will be a decisive factor in how people fare in hydro-meteorological events, including cyclones, blizzards, heavy snowfall, avalanches, coastal storm surges, floods, drought, heat-waves and cold spells.
There are barriers to action. The first may be the technical language used by warning systems. Individuals and communities may not be able to understand the meaning of obscure terms such as 'Cyclone Category 4', or the significance of a given wind speed.
Even when a community receives a warning, people's perception of risk may discourage them from heading for safety.
In 2008, for example, Myanmar's Department of Meteorology and Hydrology detected Cyclone Nargis at an early stage, but people underestimated its intensity and believed that staying indoors would offer protection from winds, floods, and sea surge.
The early warning system itself may underestimate the risk, as occurred when floods struck Mumbai, India, on 26 and 27 July 2005. A subsequent fact-finding committee found a significant gap between rainfall forecast (between 65 millimetres and 124.9 millimetres) and actual rainfall (944 millimetres — the eighth heaviest rainfall during a 24-hour period on record). Several hundred people lost their lives in the flooding.
A community's decision to act on warnings is also influenced by culture and beliefs. Some might see a disaster as an 'Act of God', or even, as in parts of Nepal, 'Devi-Prakop' — 'God's punishment' — in the face of which humans are powerless and so do not act.
The perceived benefits of taking action may not be straightforward. People sometimes hesitate to leave their homes for fear of losing belongings and assets. They also may not be confident of authorities providing facilities and protection at evacuation centres.
Another key factor is whether the infrastructure or services required for evacuation are in place. In the case of Cyclone Nargis, local communities had nowhere to take refuge, as safe shelters and evacuation protocols and procedures were lacking.
Drawing lessons from disaster
Important lessons have been learned about why early warning systems can founder.
For example, Myanmar has adopted a five-colour approach, ranging from 'yellow' (meaning a cyclone is forming in the Andaman Sea or Bay of Bengal) to 'green' (meaning a cyclone has weakened and passed) to make it easier for people to understand and react to cyclone warnings.
In Mumbai, Doppler radar is being installed to help detect localised severe rain, to help boost the credibility of early warnings and thus increase people’s confidence in their accuracy.
In Nepal, disasters are now split into three components: hazard (natural events such as earthquakes, rainfall or cyclones); vulnerability (unsafe structures, environmental degradation, lack of awareness on the dos and don'ts of disaster); and exposure (the location of vulnerable elements in flood zones and other areas of hazard).
The disentanglement of what constitutes a 'disaster' helps change attitudes to disaster management and so increases chances that a community will heed early warnings.
Furthermore, safe shelters have been built and evacuation procedures prepared in many countries, including Bangladesh, India and Myanmar. This has strengthened the last link in an early warning system.
Forging a safer future
Despite these advances, the development of end-to-end early warning has a long way to go. For example, Myanmar's five-colour warning system has to be re-examined in the light of similar schemes in other countries, and a standard colour-code system developed.
Many countries use television and radio warnings, but if read by regular newsreaders in their usual tone of voice, the warnings may be treated as 'business as usual' and ignored by many viewers and listeners. The way a newsreader announces a warning — and even a studio's background colour scheme — is also important in conveying the seriousness of a message. This needs to be studied further.
Disasters are always with us, and climate change looks set to increase the intensity and frequency of extreme events. Coping with them is an evolving discipline that requires an integrated approach involving technology, communication, social sciences and psychology.