Modeling population vulnerability and risk to extreme rainfall events in Venezuela

The vulnerability concept is intuitively simple but surprisingly difficult to define and even more difficult to quantify. There is a variety (and far from being consistent) definitions about the vulnerability concept. Vulnerability analysis is a strategy to quantify which human groups are vulnerable; where are they vulnerable and which strategies could be used to reduce their vulnerability. It provides support to governmental and non-governmental agencies for decision making towards an opportune and adequate risk management. The objective of this paper is to introduce a methodology about the data requirements and methods to be used for a comprehensive vulnerability and risk analysis. The final goal, which is not achieved in this paper, is to fully quantify these concepts by using robust methods to combine key geophysical and socio-economic factors as explanatory variables of the proposed models. We propose the following steps for a more comprehensive vulnerability and risk analysis: 1. Building a vulnerability function for the time period and region of interest. 2. Modeling precipitation extremes by using an appropriate extreme value distribution. 3. Estimating exposure to the potential damage. 4. Estimating the risk by calculating the expected losses associated with the extreme events. In the Venezuelan case, data scarcity might limit this analysis. However the methods presented provide a robust strategy to account for the different levels of uncertainty present in the analysis. More research is needed towards an improvement in risk prevention and disaster mitigation efforts and the methodology presented is intended to contribute to this effort.