A Coastal Defense Work Plan 40 Years Later: Review and Evaluation of the Espinho Case Study in Portugal

Abstract

In the 1980s, a coastal defense plan was prepared for a 110-km long stretch of the northwest Portuguese coast, from the Leixões harbor to Cape Mondego. This paper revisits the plan for the location of the Espinho beach and compares the original plan predictions with the postconstruction evolution. In addition, coastal evolution prediction is reassessed with present-day models: the one-line model LITMOD and the parabolic model (using the Mepbay software) for headland-bay beaches. In reality, one-line evolution models give overall good predictions when applied to domains of the order of 10 km, whereas empirical equilibrium-beach models are better in predicting coastal configurations close to structures in headland-bay situations. The main conclusion is that the Espinho beach is in a dynamic equilibrium, fluctuating over time but still maintaining its average position, which is in agreement with the original project predictions of the 1980s.