The role of morphodynamics in predicting coastal flooding from storms on a dissipative microtidal beach with SLR conditions: Cartagena de Indias (Colombia)

Abstract

Abstract. The main object of the present work was to study the role of morphodynamic changes in the flooding of a dissipative beach with microtidal regime, considering the simultaneous and individual effects of erosion and flooding in scenarios of long-term mean sea level rise. For this analysis, we selected a sector of the Colombian Caribbean coast with great touristic, historical, economic, cultural and social importance, namely, Cartagena de Indias; specifically, the beach of Bocagrande. By simultaneously considering erosion and flood processes associated with highly energetic waves, the study facilitates the construction of more precise models for assessing threats to coastal zones. SWAN and XBeach nested models were carried out in order to predict morphological changes and flooding during selected cold fronts and hurricanes that affected Cartagena de Indias; those numerical models were calibrated using field campaigns data (pre- and post-storm). The results of this research indicate that flooding on microtidal dissipative beaches under extreme wave conditions should be approached by considering morphodynamics, because ignoring them can underestimate flooding by ~15%. The erosion and flood effects are intensified by sea level rise, resulting in the most unfavorable condition when extreme events are contemporaneous with high tides.