A timely method for post-disaster assessment and coastal landscape survey using drone and satellite imagery.

To mitigate floods and storm surges, coastal communities across the globe are under the pressure of high-cost interventions, such as coastal barriers, jetties, and renourishment projects, especially in areas prone to hurricanes and other natural disturbances. To evaluate the effectiveness of these coastal projects in a timely fashion, this methodology is supported by a Geographic Information System that is instaneously fed by regional and local data obtained shortly (24 h) after the disturbance event. Our study assesses the application of 3D models based on aerophotogrammetry from a Phantom 4 RTK drone, following a methodological flowchart with three phases. The Digital Elevation Models (DEMs) based on aerophotogrammetry obtained from a Phantom 4 RTK drone presented a low margin of error (± 5 cm) to dispense Ground Control Points. This technique enables a rapid assessment of inaccessible coastal areas due, for instance, to hurricane impacts. Evaluation of DEMs before and after the disturbance event allows quantifying the magnitudes of shoreline retreat, storm surges, difference in coastal sedimentary volumes, and identifying areas where erosion and sediment accretion occur. Orthomosaics permit the individualization and quantification of changes in vegetation units/geomorphological areas and damages to urban and coastal infrastructure. Our experience monitoring coastal dynamics in North and South America during the last decade indicates that this methodology provides an essential data flow for short and long-term decision-making regarding strategies to mitigate disaster impacts.•Permanent and regional monitoring with spatial-temporal analysis based on satellite/aerial images and lidar data prior to the event.•Local DEMs based on drone aerophotogrammetry after the event.•Integration of regional and local planialtimetric/environmental data.

Pollen atlas and identification dataset from Santa Catarina, south Brazil.

Pollen references such as atlas and identification keys are remarkably rare from the Atlantic coasts of south Brazil. This dataset describes modern and fossil pollen from São Francisco do Sul Bay in the state of Santa Catarina, south Brazil. An illustrated and descriptive atlas of pollen was compiled from original and published data to facilitate the identification of various pollen taxa in sediments. We include light micrographs and descriptions of a total of 60 pollen taxa, including 3 mangrove taxa, 27 coastal woodland (restinga) taxa, and 15 rainforest taxa, and 15 herbaceous taxa. This dataset is associated with a published research article by Rodrigues et al. (2022) - Rodrigues, E., Cohen, M.C.L., Pessenda, L.C.R., França, M.C., Magalhães, E. and Yao, Q., 2022. Poleward mangrove expansion in South America coincides with MCA and CWP: A diatom, pollen, and organic geochemistry study. Quaternary Science Reviews, 288, p.107598.

Mineralogical and geochemical influences on sediment color of Amazon wetlands analyzed by visible spectrophotometry / Influências mineralógicas e geoquímicas na cor dos sedimentos das zonas úmidas da Amazônia analisada através da espectrofotometria no visível

Based on sedimentological and geochemical data, this work relates spectrophotometric measurements with sediment composition and its application in palaeoecological studies of Amazon wetlands. The CIELAB values are directly related to mineralogical and chemical composition, mostly involving quartz, iron oxyhydroxides and sulfides (e.g. pyrite), and total organic carbon. Total organic carbon contents between 0.4-1%, 1-2%, 3-5% and 15-40% were related to L* (lightness) data of 27, 26-15, 7-10 and 7 or less, respectively. The CIELAB values of a deposit in Marabá, Pará, were proportional to variations in quartz and total organic carbon contents, but changes in zones of similar color, mainly in the +a* (red) and +b* (yellow) values of deposits in Calçoene, Amapá and Soure, Pará, indicate a close relationship between total organic carbon content and iron oxyhydroxides and sulfides. Furthermore, the Q7/4 diagram (ratio between the % re?ectance value at 700 nm to that at 400 nm, coupled with L*) indicated iron-rich sediments in the bioturbated mud facies of the Amapá deposit, bioturbated mud and bioturbated sand facies of Soure deposit, and cross-laminated sand and massive sand facies of the Marabá core. Also, organic-rich sediments were found in the bioturbated mud facies of the Amapá deposit, lenticular heterolithic and bioturbated mud facies of the Soure deposit, and laminated mud and peat facies of the Marabá deposit. At the Marabá site, the data suggest an autochthonous influence with peat formation. The coastal wetland sites at Marajó and Amapá represent the development of a typical tidal flat setting with sulfide and iron oxyhydroxides formation during alternated flooding and drying.

Com base em dados sedimentológicos e geoquímicos, este trabalho relaciona medições espectrofotométricas com a composição do sedimento, e sua aplicação em estudos paleoecológicos das áreas alagáveis da Amazônia. Os dados CIELAB estão diretamente relacionados à composição mineralógica e química dos sedimentos, especialmente quartzo, oxihidróxidos e sulfetos de ferro, e carbono orgânico total. Conteúdos de carbono orgânico total entre 0,4-1%, 1-2%, 3-5% e 15-40% foram relacionados a dados de L* (luminosidade) de 27, 26-15, 7-10 e 7 ou menos, respectivamente. Os valores CIELAB de um depósito com turfa em Marabá, Pará, foram proporcionais a variações no conteúdo de quartzo e carbono orgânico total, mas mudanças nas zonas de cores similares, principalmente nos valores de +a* (vermelho) e +b* (amarelo), ao longo de outros depósitos em Calçoene, Amapá e Soure, Pará, indicam uma relação muito próxima entre os conteúdos de carbono orgânico total, oxihidróxidos e sulfetos de ferro. Além disso, o diagrama Q7/4 (razão entre valores percentuais de refletância em 700 nm e 400 nm, juntamente com dados de L*) indicou sedimentos ricos em ferro para a fácies lama bioturbada no depósito do Amapá, fácies lama bioturbada e areia bioturbada do depósito de Soure, e das fácies areia com laminação cruzada e areia maciça do depósito de Marabá. Ainda, sedimentos ricos em carbono orgânico foram encontrados na lama bioturbada no depósito do Amapá, fácies heterolítica lenticular e lama bioturbada do depósito de Soure, e das fácies lama laminado e turfa do depósito de Marabá. Na área de Marabá, os dados sugerem uma influência autóctone com formação de turfa. As áreas de zonas úmidas costeiras no Marajó e Amapá representam o desenvolvimento típico de planícies de maré com formação de sulfetos e oxihidróxidos de ferro durante alternâncias entre inundação e exposição.