Extended biomass allometric equations for large mangrove trees from terrestrial LiDAR data

International audienceAccurately determining biomass of large trees is crucial for reliable biomass analyses in most tropical forests, but most allometric models calibration are deficient in large trees data. This issue is a major concern for high-biomass mangrove forests, especially when their role in the ecosystem carbon storage is considered. As an alternative to the fastidious cutting and weighing measurement approach, we explored a non-destructive terrestrial laser scanning approach to estimate the aboveground biomass of large mangroves (diameters reaching up to 125 cm). Because of buttresses in large trees, we propose a pixel-based analysis of the composite 2D flattened images, obtained from the successive thin segments of stem point-cloud data to estimate wood volume. Branches were considered as successive best-fitted primitive of conical frustums. The product of wood volume and height-decreasing wood density yielded biomass estimates. This approach was tested on 36 A. germinans trees in French Guiana, considering available biomass models from the same region as references. Our biomass estimates reached ca. 90% accuracy and a correlation of 0.99 with reference biomass values. Based on the results, new tree biomass model, which had R² of 0.99 and RSE of 87.6 kg of dry matter. This terrestrial LiDAR-based approach allows the estimates of large tree biomass to be tractable, and opens new opportunities to improve biomass estimates of tall mangroves. The method could also be tested and applied to other tree species

Ambientes costeiros amazônicos: avaliação de modificações por sensoriamento remoto

The coastal plain of the State of Amapá, located on the northernmost region of Brazil, on the Amazonian coast, comprises an environmental diversity represented mainly by mangroves, lakes, swamps forests and flooded basins, related to flood plains influenced by tides and estuaries. In this study, the modifications recorded in this plain are evaluated, focusing in the region of the Araguari estuary, and the processes responsible for these changes are presented. The natural processes that influence the modifications in this plain are related to ENSO events (El Niño Southern Oscillation), position of the Intertropical Convergence Zone (ITCZ), influence of the Amazon River and tides influenced by tidal bore. The anthropogenic processes are associated with water buffalo ranching. All these factors are presented and discussed in the form of processes and products. The environmental information is from previous data and also collected in the field. The base information came from remote sensing data (aerial photographs, radar imagery - RADAR GEMS 1000 from RADAM Project, JERS- 1 and RADARSAT-1, images from optical sensors - MSS, TM and ETM+ from Landsat satellites, digital elevation model data - DEM SRTM), digitally processed for multi-sensor, multi-scale and multi-date approach. Historical maps since 16th century had also been utilized. The analyses allowed the identification of patterns of land use and cover as well as the natural and anthropogenic geomorphic features. The identified patterns and features were grouped into two main types of environments: fluvial influenced by tides (flood plain) and estuarine plain (mangrove, intertidal zone and estuarine channel). It was also possible to establish indicators to characterize the environmental modifications in the region, from multitemporal analyses of remote sensing and historical data. The tidal bore phenomenon can also be identified in the estuary by RADARSAT-1 images. The correlation between the remote sensing and historical data indicates that the Araguari River mouth had two channels until the 18th century, one to the west and the other to the south of the so-called Land of Carpori. The current configuration of the floodplain at the north and south of the estuary, and of its last meander is recent. The events related to these transformations occurred between the end of the 18th century and middle of 19th century, with indications of anthropogenic influences in some of these events. The results of multitemporal analysis of remote sensing data from the 1950s and related information had evidenced modifications in the floodplain and the estuarine plain. In the floodplain, they are related to the development of drainage networks, some of which influenced by the development of cattle ranching (e.g. the Igarapé Santana). Others had their opening influenced by great flooding events that had been correlated to ENSO phenomenon (e.g. Igarapé Novo in the Gurijuba River). In the estuarine plain, the modifications are associated with the formation of channel bars, mouth bars, changes in the tidal channels and erosional processes in the margins of the estuary. These modifications are more evident in the mouth of the Araguari River and are mainly a result of tide action and the tidal bore 3 phenomenon, which is a powerful sediment transport agent. It was also possible to analyze the phenomenon s behavior and its records throughout the estuary from observations done prior, during and after its passage. The agents associated to these modifications can influence erosional and depositional processes that act within estuarine environments of fluvial meandering systems. The results from the evaluation of remote sensing data and the techniques applied in this study had demonstrated the potential of the remote sensing tool and historical maps in the study of modifications in highly dynamic tropical coasts (of difficult access). However, these tools may present some difficulties in application to the Amazon coast, which is a region under very dynamic natural and antrophogenic processes that overlap in a short timescale, when comparing with other coastal regionsA planície costeira do Estado do Amapá, localizada no extremo norte do Brasil, abriga uma diversidade de ambientes representados principalmente por manguezais, lagos, florestas de várzea e campos inundáveis, associados às planícies de inundação dos sistemas fluviais que drenam a região costeira e estuários. Nesta pesquisa são avaliadas as modificações registradas nessa planície, com foco na região do estuário do rio Araguari e, apresentados os processos responsáveis por essas mudanças. Os processos naturais que influenciam as modificações nesta planície estão relacionados com os eventos ENSO, presença da ZCIT, influência do rio Amazonas e das marés (pororoca). Os processos antrópicos estão associados principalmente com a bubalinocultura. Estas forçantes são apresentadas e discutidas na forma de processos e produtos. As informações ambientais são oriundas de dados pré- existentes e de coletas em campo. Foram utilizados como informação de base fotografias aéreas, imagens de radar - RADAR GEMS 1000 do Projeto RADAM, JERS-1 e RADARSAT-1; imagens de sensores óticos - MSS, TM e ETM+ dos satélites Landsat e dados de modelo numérico de terreno - DEM SRTM, processados digitalmente, em abordagem multisensor, multi-escala e multidata. Cartas históricas desde o século XVI também foram avaliadas. As análises permitiram identificar espacialmente os padrões de uso e cobertura do solo e as feições naturais e antrópicas. Os padrões e feições identificados foram agrupados em dois principais ambientes: fluvial influenciado por marés (planície de inundação) e estuarino (manguezais, zonas de intermaré e canal estuarino). Foi possível ainda estabelecer indicadores para caracterizar as modificações ambientais na região, a partir das análises multitemporais dos dados de sensores remotos e cartas históricas. O fenômeno da pororoca também foi evidenciado dentro do estuário estudado. A correlação dos dados de sensores remotos com cartas históricas indica que a desembocadura do rio Araguari possuía dois distributários até o século XVIII, um a oeste e outro a sul da chamada terra de Carpori. A configuração atual da planície de inundação a norte e sul do estuário e, do seu meandro final se deve a transformações cujos eventos ocorreram entre o final do século XVIII e meados do século XIX, existindo indícios de influência antrópica em alguns desses eventos. O resultado das análises multitemporais dos dados de sensores remotos, a partir da década de 1950, e informações correlatas, evidenciaram modificações na planície de inundação e na planície estuarina. Na planície de inundação referem-se ao desenvolvimento de redes de drenagens, algumas das quais influenciadas pelo desenvolvimento da pecuária, a exemplo do igarapé Santana. Outras drenagens tiveram suas aberturas influenciadas por grandes eventos de inundações que foram correlacionados a fenômeno de El-Niño/La Niña, como o igarapé Novo que deságua no rio Gurijuba. Na planície estuarina as modificações são associadas com a formação de barras de canal, barras de desembocadura, modificação de canais de marés e processos erosionais na margem do estuário. Estas modificações são mais evidentes na desembocadura do rio Araguari e são decorrentes principalmente da ação das 1 marés (pororoca), que possui alto poder de remobilização de sedimentos. Foi possível ainda analisar como o fenômeno da pororoca se comporta ao longo do estuário e estudar os seus registros, a partir de observações efetuadas antes, durante e após a sua passagem. As forçantes associadas às modificações detectadas podem alterar a forma de atuação dos processos erosionais e deposicionais dentro de ambientes estuarinos em sistemas fluviais de rios meandrantes. Os resultados da avaliação dos dados de sensores remotos e técnicas aplicadas nesta pesquisa demonstraram a potencialidade da ferramenta de sensoriamento remoto e cartas históricas no estudo de modificações em costas tropicais (de difícil acesso), sujeitas a rápidas mudanças. Todavia, estas ferramentas podem também apresentar dificuldades de aplicação na costa amazônica, submetida a processos naturais e antrópicos muito dinâmicos, que se superpõem em uma escala temporal muito pequena, em comparação ao tempo geológico que caracteriza a evolução em outros ambientes costeiro

Ambientes costeiros amazônicos: avaliação de modificações por sensoriamento remoto

A planície costeira do Estado do Amapá, localizada no extremo norte do Brasil, abriga uma diversidade de ambientes representados principalmente por manguezais, lagos, florestas de várzea e campos inundáveis, associados às planícies de inundação dos sistemas fluviais que drenam a região costeira e estuários. Nesta pesquisa são avaliadas as modificações registradas nessa planície, com foco na região do estuário do rio Araguari e, apresentados os processos responsáveis por essas mudanças. Os processos naturais que influenciam as modificações nesta planície estão relacionados com os eventos ENSO, presença da ZCIT, influência do rio Amazonas e das marés (pororoca). Os processos antrópicos estão associados principalmente com a bubalinocultura. Estas forçantes são apresentadas e discutidas na forma de processos e produtos. As informações ambientais são oriundas de dados pré-existentes e de coletas em campo. Foram utilizados como informação de base fotografias aéreas, imagens de radar - RADAR GEMS 1000 do Projeto RADAM, JERS-1 e RADARSAT-1; imagens de sensores óticos - MSS, TM e ETM+ dos satélites Landsat e dados de modelo numérico de terreno - DEM SRTM, processados digitalmente, em abordagem multisensor, multi-escala e multi data. Cartas históricas desde o século XVI também foram avaliadas. As análises permitiram identificar espacialmente os padrões de uso e cobertura do solo e as feições naturais e antrópicas. Os padrões e feições identificados foram agrupados em dois principais ambientes: fluvial influenciado por marés (planície de inundação) e estuarino (manguezais, zonas de intermaré e canal estuarino). Foi possível ainda estabelecer indicadores para caracterizar as modificações ambientais na região, a partir das análises multitemporais dos dados de sensores remotos e cartas históricas. O fenômeno da pororoca também foi evidenciado dentro do estuário estudado. A correlação dos dados de sensores remotos com cartas históricas indica que a desembocadura do rio Araguari possuía dois distributários até o século XVIII, um a oeste e outro a sul da chamada terra de Carpori. A configuração atual da planície de inundação a norte e sul do estuário e, do seu meandro final se deve a transformações cujos eventos ocorreram entre o final do século XVIII e meados do século XIX, existindo indícios de influência antrópica em alguns desses eventos. O resultado das análises multitemporais dos dados de sensores remotos, a partir da década de 1950, e informações correlatas, evidenciaram modificações na planície de inundação e na planície estuarina. Na planície de inundação referem-se ao desenvolvimento de redes de drenagens, algumas das quais influenciadas pelo desenvolvimento da pecuária, a exemplo do igarapé Santana. Outras drenagens tiveram suas aberturas influenciadas por grandes eventos de inundações que foram correlacionados a fenômeno de El-Niño/La Niña, como o igarapé Novo que deságua no rio Gurijuba. Na planície estuarina as modificações são associadas com a formação de barras de canal, barras de desembocadura, modificação de canais de marés e processos erosionais na margem do estuário. Estas modificações são mais evidentes na desembocadura do rio Araguari e são decorrentes principalmente da ação das 1 marés (pororoca), que possui alto poder de remobilização de sedimentos. Foi possível ainda analisar como o fenômeno da pororoca se comporta ao longo do estuário e estudar os seus registros, a partir de observações efetuadas antes, durante e após a sua passagem. As forçantes associadas às modificações detectadas podem alterar a forma de atuação dos processos erosionais e deposicionais dentro de ambientes estuarinos em sistemas fluviais de rios meandrantes. Os resultados da avaliação dos dados de sensores remotos e técnicas aplicadas nesta pesquisa demonstraram a potencialidade da ferramenta de sensoriamento remoto e cartas históricas no estudo de modificações em costas tropicais (de difícil acesso), sujeitas a rápidas mudanças. Todavia, estas ferramentas podem também apresentar dificuldades de aplicação na costa amazônica, submetida a processos naturais e antrópicos muito dinâmicos, que se superpõem em uma escala temporal muito pequena, em comparação ao tempo geológico que caracteriza a evolução em outros ambientes costeiros.CNPqThe coastal plain of the State of Amapá, located on the northernmost region of Brazil, on the Amazonian coast, comprises an environmental diversity represented mainly by mangroves, lakes, swamps forests and flooded basins, related to flood plains influenced by tides and estuaries. In this study, the modifications recorded in this plain are evaluated, focusing in the region of the Araguari estuary, and the processes responsible for these changes are presented. The natural processes that influence the modifications in this plain are related to ENSO events (El Niño Southern Oscillation), position of the Intertropical Convergence Zone (ITCZ), influence of the Amazon River and tides influenced by tidal bore. The anthropogenic processes are associated with water buffalo ranching. All these factors are presented and discussed in the form of processes and products. The environmental information is from previous data and also collected in the field. The base information came from remote sensing data (aerial photographs, radar imagery - RADAR GEMS 1000 from RADAM Project, JERS 1 and RADARSAT-1, images from optical sensors - MSS, TM and ETM+ from Landsat satellites, digital elevation model data - DEM SRTM), digitally processed for multi-sensor, multi-scale and multi-date approach. Historical maps since 16th century had also been utilized. The analyses allowed the identification of patterns of land use and cover as well as the natural and anthropogenic geomorphic features. The identified patterns and features were grouped into two main types of environments: fluvial influenced by tides (flood plain) and estuarine plain (mangrove, intertidal zone and estuarine channel). It was also possible to establish indicators to characterize the environmental modifications in the region, from multitemporal analyses of remote sensing and historical data. The tidal bore phenomenon can also be identified in the estuary by RADARSAT-1 images. The correlation between the remote sensing and historical data indicates that the Araguari River mouth had two channels until the 18th century, one to the west and the other to the south of the so-called Land of Carpori. The current configuration of the floodplain at the north and south of the estuary, and of its last meander is recent. The events related to these transformations occurred between the end of the 18th century and middle of 19th century, with indications of anthropogenic influences in some of these events. The results of multitemporal analysis of remote sensing data from the 1950s and related information had evidenced modifications in the floodplain and the estuarine plain. In the floodplain, they are related to the development of drainage networks, some of which influenced by the development of cattle ranching (e.g. the Igarapé Santana). Others had their opening influenced by great flooding events that had been correlated to ENSO phenomenon (e.g. Igarapé Novo in the Gurijuba River). In the estuarine plain, the modifications are associated with the formation of channel bars, mouth bars, changes in the tidal channels and erosional processes in the margins of the estuary. These modifications are more evident in the mouth of the Araguari River and are mainly a result of tide action and the tidal bore 3 phenomenon, which is a powerful sediment transport agent. It was also possible to analyze the phenomenon’s behavior and its records throughout the estuary from observations done prior, during and after its passage. The agents associated to these modifications can influence erosional and depositional processes that act within estuarine environments of fluvial meandering systems. The results from the evaluation of remote sensing data and the techniques applied in this study had demonstrated the potential of the remote sensing tool and historical maps in the study of modifications in highly dynamic tropical coasts (of difficult access). However, these tools may present some difficulties in application to the Amazon coast, which is a region under very dynamic natural and antrophogenic processes that overlap in a short timescale, when comparing with other coastal regions.35

Expansão da rede viária na Amazônia Oriental, Rodovia Perimetral Norte, Amapá

O presente estudo trata da análise multitemporal em um trecho da Rodovia Perimetral Norte, estado do Amapá (Brasil) com a finalidade de compreender o processo de expansão da rede viária e ocupação na área. O desenvolvimento da rede viária é analisado a partir de duas categorias de estradas: oficial (resultante de estratégias políticas) e endógena (resultante da ação de agentes privados e eventuais ocupações espontâneas). Para a análise foram utilizadas 12 cenas de imagens da série do satélite Landsat entre o período de 1988 a 2014, dados da base cartográfica de estradas do programa de Zoneamento Ecológico Econômico (ZEE) e entrevistas de campo. A taxa de incremento da rede viária foi associada com eventos socioespaciais que influenciaram na expansão da rede viária. Os resultados permitiram identificar os principais atores responsáveis pelo processo de ampliação da rede viária oficial, os projetos dos assentamentos do INCRA, vinculados às estratégias políticas de ocupação regional. A evolução das estradas endógenas resultou da ação do capital de exploração mineral e madeireiro, atividades que vem se ampliando na região independente de diretrizes de ordenamento territorial. As influências dessas atividades são importantes nos processos de mudanças de uso e ocupação do território e consequentemente nos processos de desmatamento e desenvolvimento da região.Cette étude présente une analyse multi-temporelle du réseau routier de la route Perimetral Norte, état de Amapá (Brésil) dans le but pour comprendre le processus d'occupation du territoire sur la région. Le développement du réseau routier est analysé à partir de deux catégories de routes: officielles (résultant de stratégies politiques) et endogènes (résultant de l'action d'agent privé et d'éventuelles occupations spontanées). Pour l'analyse, nous avons utilisé 12 scènes de la série satellite Landsat entre les années 1988 et 2014, les données cartographiques de base autoroutes du Programme de Zonage Économique Écologique (ZEE) et des interviews sur le terrain. Le taux d'augmentation du réseau routier a été associé à des événements socio-spatiaux qui ont influencé l'expansion du réseau routier. Les résultats ont permis d'identifier que les principaux acteurs responsables du processus d'expansion du réseau routier officiel étaient les projets des établissements agricoles de l'INCRA, liés aux stratégies politiques d'occupation régionale. L'évolution des routes endogènes résulte de l'action du capital miniers et forestiers, activités qui se sont développées dans la région indépendamment des directives d'aménagement du territoire. Les influences de ces activités sont importantes pour les changements dans l'utilisation de l'espace et l'occupation du territoire et, par conséquent, les processus de déforestation et le développement de la région.This article deals with the multitemporal analysis of the network of roads in the Northern Perimetral Highway, Amapá State, Brazil, in order to understand the process of territorial occupation along the area. The development of the road network is analyzed on the basis of two categories of roads: official (resulting from political strategies) and endogenous (resulting from the action of private agents and possible spontaneous occupations). For the analysis, we used 12 scenes from the Landsat satellite series between 1988 and 2014, data from the road map database of the Economic Ecological Zoning Program (ZEE) and field interviews. The rate of increase of the road network was associated with socio-spatial events that influenced the expansion of that network. The results allowed us to determine that the main actors responsible for the process of expansion of the official road network were the projects of the INCRA settlements, linked to the political strategies of regional occupation. The evolution of the endogenous roads resulted from the action of mineral and logging capital, activities that have been expanding in the region independent of territorial planning guidelines. The influences of these activities are important for the changes in the space of use and occupation of the territory and consequently in the processes of deforestation and development of the region

Análise Multitemporal de Mudanças nas Ilhas Costeiras do Estado do Amapá Aplicando Dados de Sensores Remotos

A multitemporal analysis based on mosaics of optical and radar sensors representing the period of 36 years (1972-2008) were used to quantify the area changes in the coastal islands at the Amapá State littoral. The mosaics were built from: RadarGems 1000 images, band X, from RADAMBRASIL project; CIRCA data from 1999 and 2000 from Global Land Cover Facility and a LANDSAT TM5 mosaic elaborated by SIPAM. The mosaics were registered among each other based on the CIRCA data 2000. The coastline was extracted on hand using as a geoindicator of changes in the coastline marker, the boundary between the vegetation and the water (or intertidal zone). The results presented accretionary, erosional and migration patterns of the coastal islands, according its geographical positioning at the littoral, and, according the natural environmental constraints. The islands under marine influence as Maraca and Jipioca the erosional processes predominate with a 2.7 km (\ub1 0,0769 km) maximum linear erosion between 1972 and 2008 northward Maraca Island. The coastal islands under fluvial-estuarine influence as the islands belonging to the Bailique Archipelago, Pedreiras, Santana, Periquitos and Cajari the accretionary processes dominate with a maximum 9,8 km (\ub1 0,0769 km) between 1972 and 2008. Natural hydrodynamic and oceanographic factors are considered as the main dynamic responsible by changes in the coastal islands.Pages: 8614-862

Expansão da rede viária na Amazônia Oriental, Rodovia Perimetral Norte, Amapá

This article deals with the multitemporal analysis of the network of roads in the Northern Perimetral Highway, Amapá State, Brazil, in order to understand the process of territorial occupation along the area. The development of the road network is analyzed on the basis of two categories of roads: official (resulting from political strategies) and endogenous (resulting from the action of private agents and possible spontaneous occupations). For the analysis, we used 12 scenes from the Landsat satellite series between 1988 and 2014, data from the road map database of the Economic Ecological Zoning Program (ZEE) and field interviews. The rate of increase of the road network was associated with socio-spatial events that influenced the expansion of that network. The results allowed us to determine that the main actors responsible for the process of expansion of the official road network were the projects of the INCRA settlements, linked to the political strategies of regional occupation. The evolution of the endogenous roads resulted from the action of mineral and logging capital, activities that have been expanding in the region independent of territorial planning guidelines. The influences of these activities are important for the changes in the space of use and occupation of the territory and consequently in the processes of deforestation and development of the region

Banco de Dados Geográficos para Armazenamento e Recuperação de Dados Geológicos e Geofísicos da Planície Costeira do Amapá, Cabo Norte

The main purpose of this paper was a geographical data banc BDG construction, with a dual structure containing geological (sub-surface) and geophysical (bathymetry) information from Cabo Norte region, NE of Amapa State. The used methodology consisted in the geological and geophysical preterit data acquisition; attributes spreadsheet; re-projection of cartographic information; data converting in raster and vectorial. To structure the BDG, the software ArcView 3.2 was used and finally, the recovered data insertion was done throughout spreadsheets and vectorial data. The recovered subsurficial geological data (vibracore, pushcore, handcorer and terraces description) reached 203 entries in the whole Coastal Plain (150 at Cabo Norte, 25 at Cabo Orange, 2 at the Pedreira river , 15 at Calçoene region, 2 at Cunani region and 9 at Cabo Cassiporé). The recovered geophysical data does correspond to 152 bathymetric lines (9o at the Araguari River and 62 at Piratuba Lake). The access to the information at the BDG can be done through the selection of logical expressions; spatial analysis; hotlinks and Query, QueryBuilder and Find functions. Despite it simple structure, the BDG allows the elaboration of many representative products linked to the regional environment.Pages: 8796-880

Aplicação de dados multisensor (SAR e ETM+) no reconhecimento de padrões de uso e ocupação do solo em costas tropicais: Costa Amazônica, Amapá, Brasil

Environmental studies require information on land use and land cover. This paper presents the applicability of multi-sensor satellite data (optical and radar) for land use and land cover on the Amapá coastal plain for mapping and recognition of natural and anthropogenic dynamics. This area is influenced by the Amazon River, by tides (tidal bore) and by the Intertropical Convergence Zone (ITCZ). Anthropogenic processes are associated with water buffalo ranching. The environmental information was acquired from previous data and field observation and was correlated with remote sensing data (JERS-1, RADARSAT-1, image from ETM+ sensor from Landsat 7 and DEM SRTM), digitally processed for multi-sensor, multi-scale and multi-date approach. Eight patterns of land use and land cover were identified (mangrove, "várzea" forest, arbustive vegetation area, freshwater marsh, anthropic field, intertidal plain, estuarine channel and lakes) as well with indication of natural and anthropogenic geomorphic features. The results from the evaluation of remote sensing data and the techniques applied demonstrated the potential of the remote sensing tool for studying environments in highly dynamic tropical coastal areas of difficult access. However, these tools may present some limitations once applied to application to the Amazon coast, which is a region under strong dynamic natural and anthropogenic processes.Os estudos ambientais necessitam de informações sobre a cobertura e o uso da terra. Este trabalho apresenta a aplicação de dados de sensores remotos orbitais (óticos e de radares) na validação de padrões de uso e cobertura do solo na planície costeira amapaense para fins de mapeamento e reconhecimento da dinâmica natural e antrópica. Esta costa é submetida a uma dinâmica intensa devido à magnitude dos processos costeiros (marés-pororoca), sua localização geográfica, influenciada pelo rio Amazonas e pela Zona de Convergência Intertropical, e processos antrópicos associados à bubalinocultura. A análise foi realizada aplicando-se dados de satélite (JERS-1, RADARSAT-1, Landsat 7 e DEM do SRTM) digitalmente processados em abordagem multisensor, multiescala e multitemporal, correlacionada com dados pretéritos e informações de campo. A análise dos produtos gerados e dados colaterais permitiu distinguir oito padrões de uso e cobertura do solo: florestas de mangue, florestas de várzeas, campos arbustivos, áreas de vegetação campestre, campo antrópico, zona de intermaré, canal estuarino e lagos, além de feições morfológicas lineares associadas a estes padrões. Estas informações são importantes para o mapeamento dos ambientes costeiros e fundamentais para o reconhecimento da dinâmica na região

Comprehensive bathymetry and intertidal topography of the Amazon estuary

International audienceThe characterization of estuarine hydrodynamics primarily depends on knowledge of the bathymetry and topography. Here, we present the first comprehensive, high-resolution dataset of the topography and bathymetry of the Amazon River estuary, the world's largest estuary. Our product is based on an innovative approach combining spaceborne remote sensing data, an extensive and processed river depth dataset, and auxiliary data. Our goal with this mapping is to promote the database usage in studies that require this information, such as hydrodynamic modeling or geomorphological assessments. Our twofold approach considered 500 000 sounding points digitized from 19 nautical charts for bathymetry estimation, in conjunction with a state-of-the-art topographic dataset based on remote sensing, encompassing intertidal flats, riverbanks, and adjacent floodplains. Finally, our estimate can be accessed in a unified 30 m resolution regular grid referenced to the Earth Gravitational Model 2008 (EGM08), complemented both landward and seaward by land (Multi-Error-Removed Improved-Terrain digital elevation model, MERIT DEM) and ocean (General Bathymetric Chart of the Oceans version 2020, GEBCO_2020) topographic data. Extensive validation against independent and spatially distributed data, from an airborne lidar survey, from ICESat-2 altimetric satellite data, and from various in situ surveys, shows a typical vertical accuracy of 7.2 m (riverbed) and 1.2 m (non-vegetated intertidal floodplains). The dataset is available at https://doi.org/10.17632/3g6b5ynrdb.2 (Fassoni-Andrade et al., 2021)