Being a highly unstable environment, the transition zone presents great temporal and spatial variability. These processes are critical for the formation of different coast types, and include sea level oscillations, erosion, and depositional dynamics, associated with the action of waves, tides, marine currents and winds 2– 4. The study results reveal that the area has a negative volumetric balance of erosion and a preferential direction of sediment transport by wind, which may justify the pattern of advancement and retraction observed in the dunes of the studied area.Ĭoastal zone corresponds to the transition between the continental and marine domains, being subject to continuous morphodynamic changes that originate from the continental, marine and/or anthropogenic processes 1. Surface surveys were carried out annually between December 2015 and January 2017 to create a DEM. The use of GNSS receivers is justified by the difficulty of mapping the dune’s features using conventional methods such as theodolite, level, and total station systems, due to their high cost, time restriction sand low data precision. Geodetic techniques and precision mapping were employed to monitor the short-term coastal dynamics. The objective of the present study is to create an DEM that can evidence the complex dynamics of dune formation in the study area with use of GNSS. Wide shrubby areas (restingas, in Portuguese), lakes, mangroves, and a multitude off reshwater lagoons compose the park’s natural environments. It is located in the northeastern state of Maranhão and encompasses the largest dune fields in the country. The study area is located at the border of three major neotropical ecosystems: the Amazonia, Caatinga, and Brazilian savanna. The DEM supports the modeling studies of sand-dune evolution using multi-temporal satellite images and ground truth data, obtained through the post-processed kinematic Global Navigation Satellite System (GNSS) positioning. This paper presents a digital elevation model (DEM) of the dunes found in the Lençóis Maranhenses National Park, an environmental protection area located in the Maranhão state (Brazil).
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March 2023
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