Determination of The Wave Climate by Smc-Brazil at the Frontal Area to Guaraíras Lagoon, Ne, Brazil

The determination of the wave climate on a beach is decisive for an effective coastal planning and management since waves are one of the primary driving forces on the sediment mobilization. To characterize it, it is necessary to use either field collected data, through equipment, such as wave buoys, or applying numerical models. As Brazil has a lack of collected field data, modeling becomes a viable alternative to meet the country’s needs in this field. Therefore, the present study used the SMC - Brasil (Coastal Modeling System of Brazil) to evaluate the wave climate of the frontal area to Guaraíras Lagoon (6°10’48” South e 35°5’32” West), a region that presents an important role to the local economy, a significant environmental value and coastal erosion dynamics quite intense. The SMC-Brazil has a reliable and validated database that include several dots along the Brazilian coast containing series of 60 years of wave data each, called DOW points (Downscaled Ocean Waves), which are derived from the downscaling process of Global Ocean Waves (GOW), a model of Wave Reanalyzes Databases (Reguero et al., 2012). To designate a DOW point as representative, a statistical approach must be realized, comparing the data from the surrounding points to decide which one would most represent the others. However, the data that the DOW point has are not enough to properly describe the sea wave climate in a determined area, demanding the propagation of wave cases through the SMC – Brasil model. In this paper, 45 sea wave cases were propagated in the frontal area of the Guaraíras Lagoon mouth, generating data considering the bathymetry and contours of the seabed, on the contrary of the data from de DOW points, which are for deep waters. Four points of interest (POI) were assessed, being two for the northern side of the lagoon’s mouth and two for the southern part, both along the 5m depth contour and 10m. From the representative DOW point It was verified a predominance of waves coming from the East-Southeast quadrant (ESE), with average height and period of 1,43m and 7,3s under regular conditions; followed by East (E), with 1,39m and 7,9s; and finally, East-Northeast (ENE), with 1,3m and 10,8s.