Análise e previsão de marés na baía de Maputo

Abstract

The effectiveness of tidal prediction models depends on knowledge about the characteristics of harmonic constituents. In the present work, tide forecasts for the year 2001 of Maputo Bay, southern Mozambique, are made from tidal heights recorded in the year 2000. The in-situ data were recorded using a Tideograph - OTT anchored in the Port of Maputo by the National Institute of Hydrography and Navigation. A combination of a subroutine of the Tjide model and the Matlab program was made for the analysis and identification of harmonic constituents, their contribution to the observed tide, determination of the frequency band and the residuals. A total of 59 constituents were identified, of which 16 are the most significant, with the largest contributors being the semi-dual species, followed by the diurnal species with amplitudes of about 89.39% and 4.83% respectively. The frequency bands were located in two intervals, 0.0343966-0.0463430 cycles per hour, for the diurnal species and 0.0759749 - 0.0850736, for the semi-diones. In forecasting tides, the months of March and July had the greatest amplitude tides, while the month of September had the smallest amplitude. The fact that the lowest calculated elevation is greater than the reference level, level equal to zero, and the residuals do not show considerable discontinuities indicates that the Maputo Bay tidal forecast was successfully carried out using the T-tide, which makes the prediction with a 95% confidence level.(TRADUÇÃO NOSSA)