Development of a methodology to evaluate the flood risk at the coastal zone

Abstract

This paper illustrates the methodology developed to evaluate the risk of flooding of a coastal area, as well as the application of such methodology to Vale do Lobo beach, situated in the Loulé Municipality, a Portuguese coastal area under significant touristic pressure. The methodology is based on four main steps: a) division of the study area into sub-areas with similar characteristics in terms of coastal defense; b) determining the probability of exceedance of pre-set thresholds of flood levels for each study area; c) establishment of qualitative factors related to the consequences of exceedance of pre-set thresholds of flood levels; d) combination of the above steps for expeditious assessment of flood risks. The determination of flood levels follows the methodology presented in [1] and [2], which is based on the transference of the Faro wave-buoy regime to the study area by using the SWAN model integrated in a geographic information system (GIS)