Dinâmica sedimentar das dunas costeiras da praia de Guinjata-Inhambane

Abstract

The origin and evolution of aeolian deposits along the coast are primarily influenced by geological, oceanographic, and climatic processes. The interaction of these factors, combined with wind regimes with speeds exceeding 5 m/s blowing in the intertidal zone, has the capacity to mobilize surface sediments and transport them to the backshore, giving rise to dunes. This study aimed to: analyze the wind regime between 1994 and 2023, determine the average monthly precipitation in the city of Inhambane, and estimate the monthly mobility rate of embryonic dunes at Guinjata Beach. The research sought to identify the predominant wind direction, determine the annual average precipitation, and estimate the monthly mobility rate of embryonic dunes. The analysis was conducted using meteorological data obtained from the National Institute of Meteorology (INAM), Inhambane branch, covering the period from 1994 to 2023. These data assisted in determining the monthly averages of wind speeds exceeding 5 m/s and subsequently estimating aeolian mobility, which ranged from 27.42 to 367.96%. Sediment mobility is strongly influenced by the action of prevailing southerly winds, identified through class distribution, considering the average wind speed and direction, interpreted from the wind regime corresponding to aeolian flow throughout the year. Since this dynamic is dependent on climatic parameters, it was analysed that, during periods of low precipitation, the monthly mobility rates were higher.