HONG KONG: On the day of the Sichuan earthquake, I happened to be in Bengkulu, the province of Sumatra, Indonesia, which has been experiencing almost weekly quakes that measure about 5 on the Richter scale, following one that measured 8.5 last September. Despite its magnitude, that earthquake killed just 25 people.

This raises the question: What combination of nature, chance, human activity and government competence determines the death toll when a cyclone, earthquake or tsunami strikes?

Nothing could be more stark than the contrast between Indonesia's response to the 2004 tsunami and that of the Burmese regime to the recent cyclone disaster. In 2004, Indonesia quickly welcomed every offer of aid, even for politically troubled Aceh. This made a huge difference in reducing the mortality rate after the initial disaster. Likewise, it is hard to fault China's quick response to the recent quake in Sichuan Province.

Human behavior certainly affects the impact of natural disasters. Compare Myanmar with Bangladesh. The Ganges and Irrawaddy deltas are both vulnerable to cyclones blowing in from the Bay of Bengal. Bangladesh has responded to past disasters by establishing warning systems, safety towers and other devices to reduce the dangers to those who live on the seaboard margin of this densely populated country. Myanmar appears to have made almost no such provisions.

The problem goes still deeper. Even though Myanmar is a relatively underpopulated country, economic pressures have pushed farmers of the Irrawaddy delta to the marginal lands closest to the sea. Farms and shrimp ponds have destroyed most of the mangrove swamps that once provided a barrier between the sea and settled areas.

Moreover, in a stunning difference with Bangladesh, Myanmar has failed to irrigate the Irrawaddy delta, a process that would allow double cropping and hence reduce the pressure on land. Bangladesh now gets almost half its rice from its dry season crop, while Irrawaddy farmers still rely on a single, rain fed crop.

Once the world's major rice exporter, Myanmar now sells little overseas. The country barely feeds itself, despite having one third the population and five times the land area of Bangladesh.

Myanmar is not unique in its destruction of mangroves and other activities that promote short-term economic growth at the expense of the environment and the safety of its people. But the difference between Bangladesh - itself hardly a star - and Myanmar lies in standards of government and openness to foreign aid. Like Kim Jong Il's North Korea, Myanmar's generals have a long history of sacrificing the welfare of their people on the altar of regime survival.

Of course, bad government is not the only factor. Luck certainly plays a role. The low loss of life from the earthquake in Bengkulu last September can be mainly attributed to the region's relatively sparse population. However, another significant factor was the use of traditional, low-rise housing construction. Most houses have light, corrugated iron roofs, not the heavy tiles found throughout much of Indonesia. Thousands of homes were badly damaged when the quake struck, but few collapsed altogether.

In Sichuan, it is too early to say how much of the death toll can be attributed to poor-quality concrete buildings. But speed, not quality, has been the hallmark of China's construction boom, whether for private housing or public buildings. It seems doubtful that many builders took much notice of Sichuan's record as the most earthquake-prone province of China.

Beijing may now learn that poisoned rivers and polluted air are not the only downsides of breakneck growth. As with public health, preventive medicine works best. Minimizing the potential impact of natural disasters in obviously threatened locations is at least as important as rapid, efficient responses once disaster has occurred.