Historians have been reluctant to attribute any special role to natural hazards in shaping the course of human events, merely noting that typhoons damaged the Mongol invasion fleets of Japan in 1274 and 1281 or that the decline of feudalism in Western Europe was preceded by the Great Plague of 1347-51. Yet there is a fundamental relationship between the history and structure of societies and their vulnerability to these events. And this relationship exists no less so in the present as it did in the past, and will most certainly increase in the future. Not, of course, that natural hazards occur with the same magnitude or frequency across the globe. Some societies are inherently more vulnerable than others simply on account of their geographical location, their topography or, more recently, as a result of historically unprecedented processes of environmental change that make disasters simply ‘natural’. Currently, the populations of some 50-60 developing nations, mostly located in tropical and semitropical latitudes, are extremely susceptible to these events, and their inhabitants run a much higher risk of death from such a cause than those in middle- or high-income countries (Alexander 1993:495). In East Asia, commentators talk about a ‘belt of pain and suffering’ stretching from just below Hong Kong and the industrialised Guangzhou area of China to just north of Malaysia and Singapore (Murphy 1992:5). Even within these nations, the most vulnerable are the poorest: that billion or so of humanity whose extreme poverty leaves them little choice but to continue living in marginal urban and rural areas most at risk from these hazards.
Southeast Asia faces major environmental challenges at the dawn of the twenty-first century. While the region shares many of the same problems caused by population growth, resource depletion and global warming as other areas of the developing world, it has also experienced rapid and significant economic growth in recent decades. The effect of such activities has rendered its societies more vulnerable to disasters. However, the extent to which the frequency and magnitude of such events are determined mainly by seismicity and climate or are governed more by human activity and endeavour is a matter of past developments. As part of a wider physical environment and a larger process of historical change, the study of hazard in the Philippines needs to be located within its regional context. Specifically,