Measuring social vulnerability to climate change-induced hazards in the Philippines

Abstract

As the reality of climate change slowly sinks in the psyche of human society through the undeniable deterioration of human security among and within nations resulting from its impacts, we are now on a race against time to be prepared and proactive to mitigate its undesirable consequences on the population. One of the key tasks at hand is to better understand risk and its components of hazard, exposure, and vulnerability, which is crucial to mitigating loss and damage resulting from climate-related extremes. The Philippines is currently ranked 2nd in terms of risk according to the recent World Risk Report (Welle et al. 2014) due to its comparatively high exposure to a number of hazard types globally – typhoons, floods, earthquakes, volcanic eruptions, sea level rise, etc.

Because of its natural propensity to biophysical hazards due to its de facto exposure to a multitude of hazards, this thesis seeks to develop and test an index for social vulnerability derived from raw census data for the Philippines. As it is rare to gain access to disaggregated census data for a country, the research was allowed to formulate a social vulnerability index that is truly adapted to a particular country setting and it is unprecedented that such a rich database had been available for social vulnerability metrics. Furthermore, the research has a nationwide coverage at its most basic level of governance, the barangay, which allowed the comprehensive mapping of social vulnerability at such a detailed geographic scale. The further availability of census data from previous years also gave an added opportunity to compare social vulnerability trajectories over time.

Together with social vulnerability, the component of hazard exposure is an equally important aspect of risk and in the context of climate-change induced hazards; it also needs to be determined and delineated so that a proper assessment of these a priori measurable elements of risk can be evaluated together.

The resulting index scores were then validated against previous hazard events to determine if higher social vulnerability index scores have any influence or relationship on the outcome of disasters, in particular coastal river flooding. Another investigation then looked at the possible influence of a recurrent hazard such as typhoons on the state of vulnerability of a community.

The results reveal pretty alarming trends in terms of trajectories of vulnerability at the barangay level. Rural barangays, which tend to dominate the very high vulnerability categories have also remained consistently in the same high vulnerability states compared to their urban counterparts. At very local scales of analysis, expected relationships between vulnerability states and loss and damage incurred during extreme flood events have resulted in findings that oppose conventional literature. Finally, although there is seemingly an initial inverse relationship between typhoon hazard exposure and social vulnerability, a geographic partitioning of the samples reveal inconclusive trends.

Date of Award	5 Feb 2015
Original language	English
Awarding Institution	University of Namur
Supervisor	Sabine Henry (Supervisor)