Coastal flooding risk associated to tropical cyclones in a changing climate. Application to Port of Spain (Trinidad and Tobago)

Abstract

The aim of this paper is to provide a methodology to assess flooding risk associated to the combination of extreme flooding levels driven by Tropical Cyclone (TCs) and relative sea level rise (RSLR). The approach is based on the risk conceptual framework where the hazard, exposure, and vulnerability are defined and combined to address flooding socioeconomic consequences in Port of Spain for present and future climate (RCP8.5 in 2050). Hazard and flooding impact are assessed using a combination of statistical methods and dynamical simulations, together with a high resolution Digital Elevation Model (DEM). Combining flooding maps, exposure databases and vulnerability damage functions we have evaluated socioeconomic consequences in terms of affected population and economic damage. Besides, we have quantified the uncertainty in the results coming from the sea level rise projections and vulnerability information. The application of the methodology indicates increasing flooding threat for the future climate that could exacerbate economic losses in case of inaction. The expected annual damage (EAD) in present climate is 12.24 MUSD while in 2050 it will reach 15.22 [14.88- 15.67] MUSD.