Part II - Natural hazards and disasters: Distribution and frequencies

The analysis of the natural hazards in the region shows that there are a great variety of natural phenomena that have a great destructive potential. The hydro-meteorological phenomena (cyclones, floods, and droughts) largely dominate. All the 7 countries studied considered as a whole were above all affected by cyclones (up to 60% of the 700 events recorded between 1900 and 1996) and more than 25% of the events are floods. The other events show much lower frequencies, always less than 5%. In comparison with the other phenomena, there are many more deaths and affected people registered for floods and cyclones; approximately 95% of the deaths and affected people result from these two destructive phenomena.

According to the nature and variety of the hazards, three country groups have been distinguished:

* The Philippines and Bangladesh

These two countries both have a very high degree of exposure to various hazards but show notable differences. Bangladesh is affected almost only by hydro-meteorological phenomena (cyclones, floods, and droughts), while different hazard types including earthquakes, and volcanic eruptions are potentially present in the Philippines.

* Myanmar, Vietnam and Laos

Myanmar, Vietnam and to a certain extent Laos are affected by the majority of hydro-meteorological and induced (mass movements) phenomena and have a potentially high degree of exposure though lower than that for the above mentioned group of countries. The earthquake threat is small in all the countries except Myanmar. The threat of volcanic activity does not exist.

* Thailand and Cambodia

The principal danger in these countries is flooding.

A comparison between the potentialities of the different natural hazards and events that have occurred during the century shows that there is a strong correlation between the two, even though some phenomena like earthquakes, floods and droughts are likely to be more frequent and more a plague for certain countries than was reported during the previous times (for example Laos and particularly Cambodia).

On the other hand, some more significant distortions appear in comparing the frequency maps, number of deaths and affected people. The most obvious distortions have been observed in the Philippines and Bangladesh. There are a more significant number of disasters in the Philippines, but proportionally many more deaths and affected people in Bangladesh.

Besides the physical component, the above facts highlight the importance of the human factor and vulnerability.