Navegando por Assunto "DSAS"

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Acesso aberto (Open Access)
Análise multitemporal (1991-2021) da linha de costa (trecho Calçoene - Cabo Norte), costa atlântica do estado do Amapá.
(Universidade Federal do Pará, 2023-08-21) SILVA, Rhuan Rodrigo Pereira e; EL-ROBRINI, Maâmar; http://lattes.cnpq.br/5707365981163429; https://orcid.org/0000-0001-7850-1217
The coastline (LC) is highly dynamic due to its geographic position adjacent to the mouth of the Amazon River estuary. This region is characterized by meteorological forcings, such as a semihumid equatorial climate, high rainfall (> 2,600 mm. year-1), winds (3 to 9 m. s-1), and extreme events (El Nino - 1997/1998 and 2015/2016; La Nina - 1999/2000 and 2010/2011). It is also influenced by hydrological forcings, including water and solid discharge from the Amazon River (175,000 m³ s-1 and 1,200 Mt. year-1, respectively), and oceanographic forcings, such as hyper-tides (up to 12 m), tidal currents (2 m. s-1), waves (up to 3 m in height), and currents (up to 3 m. s-1). This study aims to analyze the multitemporal variation of the LC between the mouths of the Calçoene and Sucuriju rivers, and at the Maracá-Jipioca Ecological Station, from 1991 to 2021. The methodology includes a literature review, acquisition of LANDSAT satellite images (1991, 2000, 2008, 2014, and 2021), LC vectorization, and the application of DSAS to quantify accretion (m) and erosion areas (m) of the LC, determine retreat and advance rates (m/year and m²/year) between the mouths of the Calçoene and Sucuriju rivers, and create change polygons at the Maracá-Jipioca Ecological Station. The study area experienced predominant erosive dynamics, with an average LC retreat of 12 m. year-1 and 1.4 km² of erosion in the Calçoene-Sucuriju stretch, and 2 km² of erosion at the Maracá-Jipioca Ecological Station with an annual average retreat of approximately 18 m. Due to erosive dynamics, the study area requires special attention from public managers to prevent any type of anthropic interference that could intensify this process.
Acesso aberto (Open Access)
Detecção das mudanças costeiras na margem leste do estuário do Rio Pará: uma análise multitemporal (1987-2019) utilizando sensoriamento remoto.
(Universidade Federal do Pará, 2022-05-24) GUIMARÃES, Diandra Karina Martins; EL-ROBRINI, Maâmar; http://lattes.cnpq.br/5707365981163429; https://orcid.org/0000-0001-7850-1217; ROSÁRIO, Renan Peixoto; http://lattes.cnpq.br/8003860457518342; https://orcid.org/0000-0003-2913-0514
In the Coastal and Estuarine Zone of Pará (ZCEP) occurs a complex dynamics influenced by meteorological forces (rainfall, winds, extreme events), fluvial (flow) and marine (tides, currents, waves). The forcings affect the coastline (CL) of the estuaries margins causing changes that depend on the degree of exposure of the area and the intensity of the forcings. Therefore, the detection of the places that happen the processes of erosion and/or accretion of the coastline becomes interesting to observe the changes in the surroundings of the islands and municipalities of the eastern margin of the Pará River Estuary. The work area is located on the eastern margin of the Pará river estuary, in the section: Mosqueiro island, Santo Antônio do Tauá, Colares island (edge of the middle estuary), Vigia and São Caetano de Odivelas (edge of the lower estuary). To achieve the results, LANDSAT satellite images were acquired (1987; 1993; 1999; 2004; 2008; 2013 and 2019) and the Digital Shoreline Analysis System (DSAS) was used to more accurately identify and calculate the rates of variation of changes in erosion and accretion areas in the LC. NSM, LRR and EPR parameters were applied on the east margin of the Pará river estuary (117 km) in the 32-year period of analysis, with a total of 1130 transects generated. In the middle estuary, the tendency to erosion was higher, predominating in Mosqueiro Island with an average erosion rate of -38m and an average accretion rate of 22.97m, related to the average rates of variation of -0.58m/year (EPR) and -0.54m/year (LRR) and in Santo Antônio do Tauá with LRR and EPR parameters identifying average rates of change of -1.67m/year (LRR) and -1.55m/year (EPR). Only on the Colares island there was a tendency to accretion, with an average erosion rate of -96.29m and an average accretion rate of 116.49m, where the maximum accretion and erosion rates are 405.61m and -396.87m, respectively. While in the lower estuary there was a greater tendency to accretion, where in Vigia there was an average rate of change of 1.26 m/year and a maximum rate of accretion of 10.06 m/year in the EPR, and an average rate of change of 0.64 m/year and maximum accretion rate of 7.22 in the LRR. In São Caetano de Odivelas, the average rate of change in the EPR parameter was 0.40 m/year and in the LRR parameter it was 0.25 m/year and in the NSM it was 13.09 m. Comparing the margins of the Estuary, the east margin is under the influence of a low hydrodynamics, while the west margin is under a high hydrodynamics where erosion predominates, demonstrating that in the same estuary the processes occur in a different way, where the areas of high erosion are related to the morphology of the site and location of the area being more exposed to forcing.