Catalogus

LIM-COPAS consists of four modules: (i) meteorological model; (ii) wave generation/ propagation code; (iii) coupled morpho-hydrodynamic model and (iv) risk module via non-stationary multivariate probabilistic models. The performance of this suite of models has been tested with (i) a set of hindcast events and (ii) synthetic storm conditions. The hindcasted events have been: December 2008 (D-08); October-2015 (O-15); November 2015 (N-15); January 2016 (J-16); February 2016 (F-16); December 2016 (D-16) and January 2017 (J-17).

In D-08, errors in nearshore spectral wave parameters have been about twice than those in the offshore area. The error was around 20% in hydrodynamics and 50% in morphodynamics. The post-storm response has been acceptably reproduced, with a Brier Skill Score near 0.4.

LIM-COPAS has shown good accuracy with high return period events (i.e. Tr,waves _ 10 yrs, D-16 and J-17), but lower agreement was found for milder storms (i.e. O-15 and F-16).

The meteorological module provided wind fields that were systematically overestimated. The integrated Mean Bias (MB) was −1.52 ± 0.78 m/s. Tarragona (Coefficient of Efficiency, COE = 0.27±0.13) and Begur (COE = 0.29±0.17) had metrics above the average value (COE = 0.24 ± 0.14); but lower agreement was found at Mahón (COE = 0.13 ± 0.16) and Dragonera.

Wave metrics were more accurate than for the wind fields. The integrated Hs COE was 0.52±0.12 and Tm02 COE was 0.36±0.14. At the central coast, Hs has presented good metrics: low MB (−0.06 ± 0.08 m) and high COE (0.58 ± 0.11). The northern coast metrics were the most stable.

The newly developed risk module has been implemented at 79 beaches. Erosion has been estimated as a bounded cost, whereas flooding as a high upside cost. Dissipative beaches tend to exhibit higher costs than reflective beaches under high sea levels. Tr,waves _ 10 yrs events joint with storm-surges can lead to significant damage costs. The estimated losses for the N-15 event (2510·103euros) do not differ excessively from J-17 (3200 · 103 euros).

Two types of QDM have been numerically tested: (i) sand dunes and (ii) geotextile detached breakwaters. The benefits from maintaining the sand volumes outperform the flooding cost reduction. In general terms, the detached breakwater can be a suitable option for beaches in an intermediate morphodynamic state against low to moderate sea levels and high wave return periods. At dissipative beaches, dunes are the best option, but they require a minimum beach width (around 30 m) that ensures their lifetime.