Navegando por Orientadores "SOUZA FILHO, Pedro Walfir Martins e"

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Acesso aberto (Open Access)
Análise da dinâmica da cobertura e uso do solo na bacia hidrográfica dos lagos Bolonha e Água Preta, Belém, Pará.
(Universidade Federal do Pará, 2024-12-20) BARROS, Jackison Mateus Lopes; SOUZA FILHO, Pedro Walfir Martins e; http://lattes.cnpq.br/3282736820907252; https://orcid.org/0000-0003-0252-808X
The increase in the urban population in the world has impacted river basins that supply water to cities, including the treatment and distribution of drinking water for domestic, industrial and commercial use. One example is the Bolonha and Água Preta Lakes Hydrographic Basin (BHLBA) in the Belém Metropolitan Region (RMB), the second largest urban agglomeration in the Brazilian Amazon, with 2.3 million inhabitants. One of the best ways to monitor the dynamics of river basins is through remote sensing techniques with orbital images, due to the quality of the spatio-temporal data. This work aims to analyze the changes in land cover and use in the last four decades in the BHLBA, through images from the Landsat satellite series from the years 1984, 1989, 1994, 1999, 2004, 2008, 2018, 2021 and 2023, using a geographic object-oriented image analysis (GEOBIA) methodology. Thus, the classes of lakes (L), urban area (AU), aquatic macrophytes (MA), arboreal vegetation (VA) and pasture (P) were evaluated. The overall accuracy of the images showed values around 90%, with the main error being allocation errors. Changes that occurred over the years were identified, such as the significant growth of macrophytes on the water surface of the Bolonha and Água Preta lakes, which decreased by approximately 3.7%. A 13.4% increase in arboreal vegetation in the BHLHA was also recorded, evidencing a forest recomposition. A 3.2% growth in urban areas around the BHLBA was also observed, which is worrying because human influence can put the health of the water supply sources of the RMB at risk. The GEOBIA methodology proved to be adequate for the study and we recommend that monitoring be continued due to the socio environmental importance of the area under study.
Acesso aberto (Open Access)
Análise da dinâmica das áreas de manguezal no litoral Norte do Brasil a partir de dados multisensores e hidrossedimentológicos
(Universidade Federal do Pará, 2016-12-16) NASCIMENTO JUNIOR, Wilson da Rocha; SOUZA FILHO, Pedro Walfir Martins e; http://lattes.cnpq.br/3282736820907252
The objective of this research is to analyze the dynamics of the mangrove areas in the north coast of Brazil from images of remote orbital sensors and hydrosedimentological data (flow and suspened sediment concentration). We tried to understand the existence of causality between the expansion or retraction of the mangroves with the suspened solid discharge calculated from the data of flow and suspened sediment concentration. The mangroves were mapped, using the object oriented classification technique, in the years 1975, 1996 and 2008 based on data from microwave sensors (RADAM / GEMS, JERS-1, ALOS / PALSAR). The data of fluviometric stations and sediments of the National Water Agency were used to calculate the solid discharge in suspension in the rivers Araguari, Gurupi, Pindaré, Grajaú and Mearim seeking to relate the addition and erosion in the areas of mangrove with the sedimentary load of the rivers that drain On the coast. The flow variations reflect the precipitation in the sub-basins of the analyzed rivers and presented a strong and moderate correlation with the temperature anomalies on the surface of the Pacific Ocean evidencing a relation of the El Niño and La Niña phenomena with the precipitation regimes in the Amazon. The variations of suspended sediment concentration were not related to the fluviometric variation suggesting that the annual mean oscillations are reflections of other phenomena (coverage and land use). The results show that the drainage areas of the sub-basins most impacted by the anthropic action contribute with a higher sediment load to rivers that have a higher concentration of native forest. Native vegetation contributes to containment of soil erosion and exposed soil and pasture areas are more vulnerable to soil erosion. The Gurupi, Pindaré, Grajaú and Mearim Rivers presented solid suspended load higher than or equal to the Araguari River. Analyzing the mangroves in the estuaries we noticed the addition of mangroves along the estuaries of the Gurupi and Mearim rivers (Baia de São Marcos) and the reduction of mangrove areas in the Araguari estuary. The Amazon coastal zone is subject to natural processes of great magnitude, but atrophic activities influence the natural dynamics of the region by implementing unsustainable economic practices.
Acesso aberto (Open Access)
Análise de imagens de sensores remotos orbitais para mapeamento de ambientes costeiros tropicais e de índices de sensibilidade ambiental ao derramamento de óleo no Golfão Maranhense
(Universidade Federal do Pará, 2006-04-18) TEIXEIRA, Sheila Gatinho; SOUZA FILHO, Pedro Walfir Martins e; http://lattes.cnpq.br/3282736820907252
The oil spills in Brazil are more and frequents, causing several impacts on environments and biological communities. Envronmental sensitivy index maps of oil spils are indispensbles components of contingency and emergency answer plans for this tpe of accident. These maps present a system of classification based on geomorphologic characteristics of the áreas, which are defined by the following factors: wave and tidal energy exposure relative degree, shoreline slope and substrate type, and also, the easiness to clean and remove the oil impacted áreas. In this contect, the “Golfão Maranhense” region, located on Northern “Maranhão” State, was chosen in order to map and analyze the environmental sensitivity indexes (ESis) of oil spills on coastal environments, for in this área, we find the second largest port in draught of the world, the Porto f “Itaqui”. Moreover, this region is the route of six hundred oil tankers per year, which are potential agents that cause the oil spill. The methodological approach for creating the maps of environmental sensitivity index included the integrated analysis of coastal environments based on digital image processing from remote optical sensores, in this case, Landsat-4TM, CBERG-2 CCD and SPOT-2 HRV, SAR (Synthetic Aperture Radar) images from RADARSAT-1 Wide 1, SRTM (Shuttle Radar Topography Mission) elevation data, geographic information system and Field surveys related to geomorphology, topography and sedimentology. Using the aforementioned methods, the coastal environments recognized in “Golfão Maranhense” were grouped according to their envronmental sensitivity index: 1 – Solid men-made structures (ESI 1B); 2- Cliffs (ESI 1C); 3 – Fine grained sand beaches and móbile dunes (ESI 3ª); 4- Tidal sandflats (ESI 7); 5- Mixed intertidal Banks, tidal mudflats and ebb-tidal delta (ESI 9ª); 6- Supratidal sandflat (ESI 9C); 7- Saltmarshes (ESI 10ª); 8- Fresh marhes and intermittent lakes (ESI 10B) and 9- Mangrove (ESI 10C). This approach is efficient to recognize and analyze coastal environments and, therefore, it pernitted the sensivity index attribution for the oil spill on yhese environments, in a georefenced data base, which allows making faster e more efficiently decisions in case oil spills come to happen.
Acesso aberto (Open Access)
Análise de imagens Landsat ETM, Radarsat-1 e modelos numéricos de terreno para o mapeamento dos índices de sensibilidade ambiental ao derramamento de óleo na costa de manguezais do nordeste do Pará
(Universidade Federal do Pará, 2006) BOULHOSA, Messiana Beatriz Malato; SOUZA FILHO, Pedro Walfir Martins e; http://lattes.cnpq.br/3282736820907252
Accidents related to exploration and oil transport are a threat to coast zones araund the world. Oil spills are an ecological disaster that may cause irreparable damage to the environment affecting living beings that live in these coast zones and also the local economy. Characterizing coast environments is very complex because of the many limiting factors during the mapping process. When it comes to humid tropical environment, like in Pará northeast coast, it gets worse because this area is typically dominated by macro tide. First of all, the macro tide plain creates low areas where informations about the relief are, most of times, scarce and the plain metric representation is dominant. Secondly, the tide variations with its vertical and horizontal moving produces strong changes on the sediment coast environment limits. Thirdly, the geomorphological modifications in the coast areas are intense and fast. Towards this context, the objective of this master’s degree dissertation is to create a map of the coast environment and a rating map of the environmental sensitivity about the oil spills in a certain part of Pará state northeast coast. The methodology consisted on processing digital images from remote sensors in the range of optical (Landsat ETM +7) and microwave (RADARSAT–1 Wide-1) associated to data from the SRTM (shuttle radar topographic mission) digital model of elevation, and to the field data collected in SIG (geographical information system) environment, providing an integrated analysis of the spectral, geomorphological, altimetrical and sedimentological characteristics of the coastal environments in cartographic georeferenced bases. The most important results of this dissertation allowed: 1) The evaluation of the potential of the images Landsat ETM +7, RADARSAT-1 and of the multi sensors fusion products used for identifying the coastal environment and the Environment Sensitivity Rates (ISA) of oil spills in this areas 2) Recognizing and describing five main morphological unities and fourteen sub unities: Coastal Plateau, Tide Plain, Coastal Plain and Alluvial Plain 3) Identifying and classifying eight unities of Environmental Sensitivity Rates (ISA) for the Amazon coast zone which are: ISA 1B – support wall; ISA 3B – exposed scarps with declivity to the sand; ISA 9B – sand bank and plains of tidal vegetable mudflats; ISA 9C – hypersalt herbaceous fields, ISA 10A – salt and salobre herbaceous fields; ISA10C – Mangrove; ISA 10D – Lea; 5) creation of the Environmental Sensitivity Rates map to oil spill of the studied area. The using of remote sensors techniques and SIG proved to be an important tool for recognizing and analyzing coast environments and for generating maps to coast environments and to environmental sensitivity rates to oil spills in the northeast coast of Pará.
Acesso aberto (Open Access)
Análise do padrão espectro-temporal de ambientes costeiros com imagens Landsat, Ilha de Marajó/PA.
(Universidade Federal do Pará, 2010-10-06) CARDOSO, Gustavo Freitas; SOUZA JUNIOR, Carlos Moreira de; http://lattes.cnpq.br/2090802631407077; SOUZA FILHO, Pedro Walfir Martins e; http://lattes.cnpq.br/3282736820907252
Knowledge of spatial and temporal distribution and monitoring of its dynamic evolution are the most important factors for the study and management of wetlands. The aim of this study was to characterize, to map, to compare the spectral response of coastal wetlands, as well as detect the changes on the eastern shore of Marajo, State of Pará, using images from TM Landsat-5 reflectance. To this end, the images were geometrically and radiometrically corrected. Were collected in the reference image (2008), at least 20 polygonal samples (5x5 pixels) for each type of land cover. The analysis of variance (ANOVA), Tukey HSD Test and an index of spectral separability of pairs of regions of interest (ROIs) were calculated. The mapping was generated from the supervised classification Spectral Angle Mapper, and validating data, outlined by the Confusion Matrix. Thus were recognized the following units: MAN - mangrove, MAD - degraded mangrove, PRD – beaches and dunes, VSI – initial secondary vegetation, VSA - advanced secondary vegetation, ACS – water with sediment, ASS - water without sediment, OCH - human occupation and CAM – marshes. The result of ANOVA showed that there are significant differences between the average reflectance in all classes and at least one pair of means, for all bands (1-5 and 7) image. The Tukey HSD test found that the smallest difference between two means of bands 1 and 2 occurs in pair VSAMAN, the band 3, VSI-MAN, the band 4, OCH-MAN, the band 5, OCH-PRD, and band 7, ASS-ACS. The function of spectral separability of pairs of ROIs highlighted a low value for the pair of classes OCH-CAM. The calculation accuracy of the mapping showed acceptable values. Was also applied the technique of spectral mixture model to determine the fractions – green vegetation, water and/or shade, soil and vegetation not photosynthetically active – in reflectance images in years from 1988, 1994, 1998, 2004, 2006 and 2008. The detection of changes over the years was done with the help of the tri-linear diagram of Thompson, used to analyze the evolution of Mangrove environments, Salt Marshes with a predominance of soils, Grassland Salt Marshes, Beaches and Dunes, Wet Sediment, Water with Sediment and Water without Sediment. The results showed that 80% of the samples from mangrove environment, maintained their spectral characteristics, ie, the environment has not changed over time, and that 15% of possible paths indicated a gradual change for the formation of mangrove until 2008. Of the total number of pixels analyzed for this environment, 93% corresponded to the actual mangrove, confirming a relative stability of this environment in the study area. Salt Marshes showed an unusual condition in the analysis of the image of the reference year (2008), with spectral response similar to the soil characteristics, this is not checked in years gone by. In recent years, there was a predominance of Grassland Salt Marshes. As for the environment Beaches and Dunes revealed a considerable increase of its surface (66.7%) in the 20-year period (1988-2008). Overall, the results suggest that the study area has undergone the process of progradation of sediments along the shoreline and stabilization in the increase of surface Mangrove since 2006. For the Salt Marshes detect the variations in the abundance values among the three fractions (Green Vegetation, Shade/Water, Non-photosynthetically Active Vegetation and Soil) generated by the spectral mixture model, mainly due to seasonal climate in the region. The method of change detection applied fostered the development of a model spectral dispersion diagram for coastal wetlands. This model should assist in future research about the monitoring of the impacts of the humid coastal environments from the increase in sea level, the location and spectral characterization, and change detection.
Acesso aberto (Open Access)
Análises texturais de produtos derivados de LiDAR para discriminação de cangas lateríticas, Serra Sul de Carajás (PA)
(Universidade Federal do Pará, 2016-09-30) SANTOS, Jaqueline Alcântara dos; SILVA, Arnaldo de Queiroz da; http://lattes.cnpq.br/1682623730626187; SOUZA FILHO, Pedro Walfir Martins e; http://lattes.cnpq.br/3282736820907252
The characterization of geological features through products derived from remote sensing in humid tropical regions suffers severe restrictions due to the influence of vegetation on the radiometric measurements. This is the motivation to investigate new methodological approaches aimed at extracting remote sensing information data applied to geological mapping. This research aimed to develop a methodological approach to discriminate types of lateritic surfaces from textural parameters of the Haralick extracted shaded relief image generated Digital Model Land of high spatial resolution (1 m) derived from the last return signal (ground) of LiDAR data. The study area is located in body S11CD in Serra Sul of Carajás Mineral Province, including the city of Canãa dos Carajás (Pará State - Brazil). The body S11CD is characterized by a residual relief supported by ferruginous crust thick developed on Archean banded iron formations (Carajás Formation / Grão Pará Group) and is covered by savannah (campus rupestres) that contrast with the surroundings tropical rain forest. The lateritic crust in the study area is classified into (1) structural duricrust and (2) detrital duricrust. The difference between the types of lateritic crust was analyzed by microtopography relief metrics (Hrms), measured in the field and textural parameters of the Haralick extracted from the shaded relief image. Statistical tests of averages Hrms comparison (Student t test) showed that it is possible to identify the terrain microrugosidade kinds of lateritic duricrust present in S11CD. The object-oriented classification (GEOBIA) was used dissimilarity textural parameter of the Haralick to discriminate the types of lateritic duricrust. For this, it was used the standard deviation of the average dissimilarity threshold for separating the detrital duricrust (26.1 ↔ 33.234) and structure duricrust (20.573 ↔ 28.515). The result of this classification overlaid around 89.35% the study area, remaining ~ 11% of the image not classified, possibly as a result of noise in the LiDAR data. The validation of this classification attested that the overall accuracy of field data and the classification was 78.8%. Note also, that the structural duricrust occurs in the area as small "windows" through the detrital duricrust, which made it difficult to carry out field sampling at this site, so the errors of commission and of omission become high.
Acesso aberto (Open Access)
Aporte hídrico e de material particulado em suspensão para a Baía do Marajó: contribuições dos rios Jacaré Grande, Pará e Tocantins
(Universidade Federal do Pará, 2014-03-19) COSTA, Maurício da Silva da; ROLLNIC, Marcelo; http://lattes.cnpq.br/6585442266149471; SOUZA FILHO, Pedro Walfir Martins e; http://lattes.cnpq.br/3282736820907252
The Amazon estuary is influenced by the tide and river discharge systems variations that modify the currents and contribute with inputs of suspended particulate matter (SPM) resulting in morphological changes along the river. The quantification of these parameters provides an understanding of the rates of export and import of materials or volume and its implications in the estuarine geomorphology. The aim of this study is to evaluate the hydrodynamic, volume transport and SPM in different periods in Jacaré Grande, Pará and Tocantins rivers. Speed and current direction, tide, turbidity, volume transport and SPM data were collected over a tide cycle in the dry (2012) and rainy (2013) periods. The Pará river the exported volume in both periods, while the Tocantins river imported during the dry period and the exported in the rainy period. The Jacaré Grande river, influenced by the Amazon river, imported in the rainy season and exported in the dry period. The analysis of the volume transport methods showed a trend of export toward Amazon river and Marajó Bay in the dry season and only toward the Marajó Bay during the rainy season. SPM values were higher in the rainy season and descending from Jacaré Grande river to the Tocantins river in dry and rainy season, respectively. Turbidity followed the same trend of SPM with tide, with maximum values during the flood. SPM transportation methods showed similar values and the same direction. The Jacaré Grande river served as an exporter during the dry period and as an exporter in the dry period, the Para river as an exporter in both periods and the Tocantins river in the dry season as an importer and as an exporter during the rainy season. The system formed by the three rivers showed the same trend of export in both periods, with two exportation routes in the dry season (Amazon river and Marajó Bay), and only one exportation route in the rainy period (Marajó Bay). Annually the system exports between 5 and 7.2 million tons and possibly the Marajó Bay receives 3.7 to 5.8 million tons. The volume transported to the ocean can be much higher. SPM flows, associated with the variability of environmental conditions, molds the estuary, as seen in the mouth of the Tocantins river and Guajará Bay. Thus, it important a continuous monitoring due to the potential boating accidents, oil spills or any contamination in the region that can result in damage the enviroment.
Acesso aberto (Open Access)
Avaliação da exatidão cartográfica de dados SRTM e atualização da carta plani-altimétrica Salinópolis - NE do Pará
(Universidade Federal do Pará, 2009-05-22) MARTINS, Elainy do Socorro Farias; SOUZA FILHO, Pedro Walfir Martins e; http://lattes.cnpq.br/3282736820907252
The Brazilian topography information, in 1:100.000 scale, covering only 75,39 % of the country, leaving many empty mapping, especially in Amazon region. This information was derived by aerophotogrammetric methods, applied in aerials photos of the 60 to 80 decades. Because the complexity of applied methods and others technician problems, most of planialtimetric maps are outdated, which impossibility the use of them. Nowadays, the topography information is largely derived from digital elevation models, for example, imageries of Shuttle Radar Topography Mission (SRTM). In this paper, the SRTM was analyzed based on altimetric Cartography Accuracy Standard (PEC), in the update of Salinopolis map of 1982. The analysis of SRTM altimetry, on Salinópolis region, showed that it can be used in class C scale 1:50,000 and Class A scale 1:100,000. Since the SRTM images are compatible with the scale and class of Salinópolis map, was used the original version of the SRTM (90 meters spatial resolution) to update altimetry and Landsat TM-5 imagries on planimetric base, following Brazilian Institute of Geography and Statistics parameters. With the update was found several differences, mainly in relation to planimetry. The update is very important, especially in coastal regions due to the dynamics and intensity of the different natural processes and man-made active, in addition, this methodology could be the basis for the upgrade of other maps and generation of new maps without this in of information, thus resolving the issue of lack of topographical information in certain ranges. Keywords: SRTM, cartography update, topographic charts, Amazon.
Acesso aberto (Open Access)
Avaliação de dados de sensores remotos no reconhecimento e monitoramento de ambientes costeiros tropicais: cabos Cassiporé e Orange, Amapá
(Universidade Federal do Pará, 2006-09-18) BATISTA, Edmilson das Mercês; SOUZA FILHO, Pedro Walfir Martins e; http://lattes.cnpq.br/3282736820907252
Acesso aberto (Open Access)
Detecção de mudança e sedimentação no estuário do Rio Coreaú
(Universidade Federal do Pará, 2014-09-02) RODRIGUES, Suzan Waleska Pequeno; SOUZA FILHO, Pedro Walfir Martins e; http://lattes.cnpq.br/3282736820907252
The use of new techniques to study the evolution and filling incised valleys has provided, over the years, important results was to understand how the coastal evolution of the Brazilian coastal zone. In this context, this thesis aimed to study the evolution of the estuary Coreaú River, located in the state of Ceará, in different time scales, is "Possible" (months, years), "Engineering" (years, decades) and "Geology" (hundreds, centuries, millennio), proposed by Cowell et al (2003), with the goal to assess whether changes /alterations over the years were significant or not in the estuary. As a result, we obtained the first goal, using remote sensing techniques from image sensor TM, ETM+ and OLI of Landsat 5, 7 and 8 and sensor LISS-3 of satellite ResourceSat-1 from 1985 to 2013, a change minimal in relation to morphological changes along the estuary in the last 28 years (between Possible scales and Engineering), there was an increase in this period of 0.236 km2 (3%) of the area, not bringing significant changes to the estuary. Regarding sedimentation rate, corresponding to the second goal, from the collection of nine witnesses, up to 1m deep and using radionuclídeo 210 Pb along the estuary, we obtained a rate that ranged from 0,33 cm/year 1 cm/year (between scales Geological and Engineering) near the mouth of the estuary, and with a quick sedimentation perceived on the east bank of the river, where there are younger sediments toward the west margin. Regarding the fulfillment, third and final goal from the sampling of testimonials to 18 m depth, using the sampler Rammkernsonden (RKS), profiles and stratigraphic sections that helped understand filling the valley section of the estuary of the Coreaú river were generated and that it is a fluvialmarine estuary, filling the valleys formed in group Barriers in the last 10.000 years before present. These analyzes and results serve as a basis for comparison with other estuaries, either fluvial, fluvio-marine or marine, to better understand what the possible events that dominated sedimentation along the coast of Brazil at diferent scales.
Acesso aberto (Open Access)
Detecção de mudanças na costa de manguezais da Amazônia a partir da classificação de imagens multisensores orientada a objetos
(Universidade Federal do Pará, 2011-03-03) NASCIMENTO JÚNIOR, Wilson da Rocha; SOUZA FILHO, Pedro Walfir Martins e; http://lattes.cnpq.br/3282736820907252
Mangroves presents great importance to the ecological balance, and a nursery conducive to the development of various animals and plants. In recent years, degradation of mangroves has been occurring more frequently due to the plundering of their natural resources, land planning and poorly planned tourist activities. By remote sensors can map large areas of the area more quickly and efficiently. The objective is to map the distribution of mangrove areas to the east of the Amazon River into the Bay of San Marcos in 1996 and 2008 from remote sensing data. The mapping, change detection and quantification was performed by ALOS / PALSAR, JERS-1, SRTM and Landsat 5 TM. In order to classify the images, we used the software Definiens Ecognition 8, which uses the logic of object-oriented classification. In the classification of the mangrove was an elaborate process tree that stores all the elements or rules (segmentation, algorithms, classes and attributes) needed to obtain the final classification. The result of the quantification of the mangrove was 6705,05 km ² (1996) and 7423,60 km ² (2008) which shows a net increase in mangrove area of 718,55 km ². The change detection map allowed an overall increase of 1931,04 km ², a total erosion of 1212,49 km ², remaining an area of 5492,56 km ² of mangrove unchanged. To statistically validate the results, we elaborated two confusion matrices containing the rights and wrongs of the classification. The error matrix for validation of the classification of classes mangrove swamp, upland, water mass, secondary vegetation, fields and lakes showed an overall accuracy rate = 96.279%, Kappa = 90.572% and 92.558% = index Tau, which showed the classification efficiency of mangroves in relation to other classes used in processing. The error matrix for validation of classification and Non-Change Change of mangrove area showed high accuracy Global = 83.33%, Kappa = 66.10% and 66.66% = index Tau. Therefore, we conclude that the method of object-oriented classification logic is excellent for mapping mangroves and very good for the detection of changes in tropical coastal areas. Regarding the expansion of mangrove areas, it is observed only in the Amazon region, as opposed to what is observed in other large systems of mangroves, such as the Gulf of Papua New Guinea and the Sundarbans in Bangladesh and India. The results were used to compose a mosaic of regional and global mapping of mangrove and ratify the large expanse of mangrove forests in Amazonian Brazil as one of the best preserved of the planet.
Acesso aberto (Open Access)
A dinâmica dos manguezais no Nordeste do Brasil: uma abordagem a partir de dados de sensores remotos e SIG.
(Universidade Federal do Pará, 2015-11-27) PEREIRA, Edson Adjair de Souza.; SOUZA FILHO, Pedro Walfir Martins e; http://lattes.cnpq.br/3282736820907252; 3282736820907252
This study assesses the dynamics of mangroves in the northeastern Brazil in the last four decades from the classification of remote sensing images based on geographic objects (GEOBIA). This methodology combines spectral, temporal and spatial information of multi-temporal images to create consistent objects (mangrove areas) for a statistical analysis from classified images. The objective of this study was to evaluate the changes in mangrove forest cover in all states of the northeastern Brazil between 1975 and 2008, with regard to the increase or decrease mangrove areas in response to natural (erosion and accretion) and anthropogenic (Aquaculture / salinicultura) variations. In this study were processed and analyzed remote sensing images (RADAMBRASIL, ALOS PALSAR, TM Landsat and SRTM) from GEOBIA approach. During the studied period, there was a reduction of ~ 1,545 km2 mangrove forest area in 1975 to ~ 1480 km2 in 2008. This represents a net loss of ~ 65 km2, which is equivalent to a decrease of 13% in the mangrove forest area. Of the nine states studied, only Ceará and Pernambuco showed a gain in coverage of mangroves, while all others were reduced. Among the total mangrove forest area lost during the study period (~ 953 km2), the aquaculture/saliniculture ponds represent ~ 10%. Importantly, in the states of Rio Grande do Norte and Ceará the conversion of mangrove areas for aquaculture/saliniculture ponds already represent ~ 41% and 32% of the total area of mangrove lost, respectively. Therefore, it concludes that the methodology used to assess the dynamics of mangroves in northeastern Brazil from different sources of remote sensing data was extremely effective. New strategies for recovery and sustainable use of mangrove areas should be established in order to conserve this ecosystem for future generations.
Acesso aberto (Open Access)
Distribuição espacial e avaliação de indicadores de contaminação de sedimentos por metais em um estuário tropical de macromaré, Baía de São Marcos, Norte do Brasil
(Universidade Federal do Pará, 2023-03-30) CUNHA, Ivson Roberto Viana da; KUTTER, Vinícius Tavares; http://lattes.cnpq.br/6652786694334612; https://orcid.org/0000-0001-7295-6800; SOUZA FILHO, Pedro Walfir Martins e; http://lattes.cnpq.br/3282736820907252
The estuaries are areas of great ecological importance for having the role of nursery, feeding and reproduction area for several aquatic species, in addition to housing large metropolitan and industrial. However, they are exposed to various types of contaminants, including metals because of anthropic action. In this context, the estuary of São Marcos Bay (SMB) in northern Brazil, which has an urban area with more than one million inhabitants and the port area with the largest cargo transport in the country (182 million tons in 2021). The present study evaluated the presence of metals (Cr, Cu, Ni, Pb and Zn) in the surface sediments of São Marcos Bay adjacent to São Luís Island and the quality of the sediments, their relationship with granulometry, total organic carbon (TOC) and in the classification of geochemical indices. Surface sediments were collected with the aid of a Gibbs dredger, in two sectors of the SMB, one adjacent to the port area and the other to the São Luís metropolitan região. In the laboratory, the samples were submitted to the granulometric analysis process by laser diffraction; determination of metals by Inductively Coupled Plasma - Mass Spectrometry (ICP-MS) and the total organic carbon content by means of the catalytic combustion method at high temperature. The results demonstrate a strong correlation between metal concentrations, granulometry and TOC. Since Cr and Zn showed high concentrations observed in sector A in areas with a predominance of fine sediments and high TOC content. In sector A the median was 16 μg/g (Cr), 4.6 μg/g (Cu), 6.5 μg/g (Ni), 4.6 μg/g (Pb) and 18 μg/g (Zn). While in sector B: 9 μg/g (Cr), 2.2 μg/g (Cu), 3.7 μg/g (Ni), 3 μg/g (Pb) and 7 μg/g (Zn). The evaluation of the concentration of metals in the BSM sediments showed that, according to the criteria adopted by CONAMA 454/12 and NOAA, the analyzed metals present concentrations below those that could cause some type of adverse effect on the biota, and therefore, affect the balance of the ecosystem. The geoaccumulation index (Igeo) shows variations from moderately to heavily polluted for the analyzed metals. However, these classifications are not supported by other methods. For example, the contamination factor and the enrichment factor appreciated that the area has low contamination and a low enrichment for metals. The use of local background values, observing that the use of reference values for the continental crust or for shales (PASS) tends to overestimate the infection indicators.
Acesso aberto (Open Access)
Duas décadas de mudanças dos manguezais de meso e micromarés do litoral brasileiro a partir de imagens multisensores
(Universidade Federal do Pará, 2020-05-25) LOPES, João Paulo Nobre; SOUZA FILHO, Pedro Walfir Martins e; http://lattes.cnpq.br/3282736820907252; 3282736820907252
Mangroves are coastal environments that extend along the tropical and subtropical global coastal regions, whose constant monitoring is hampered by its large-scale distribution. With the advent of new computational technologies supported by remote sensing (Google Earth Engine - GEE), this problem has been partially solved. However, some limitations still persist, for example, the use of an image library using only optical sensors, making it difficult to map mangrove forests in areas frequently covered by clouds. Thus, this work aims to evaluate the classification and changes in the mangrove areas of the meso and micro-tidal regions of the Brazilian coastal zone in the last two decades through multi-remote sensor data (optical and microwaves) from geographic object-based image analysis (GEOBIA). Multitemporal images from the Landsat, Alos PalSar, JERS SAR and SRTM series were used. The remote sensing dataset were processed according to the GEOBIA approach, which determines the reduction of an image in homogeneous regions (objects) by grouping sets of pixels with similar characteristics. As a result, it was observed that in 1996 and 2016 the area under study contained 2625,38 km² and 2898,26 km² of mangrove areas, respectively. This demonstrates an increase of 273 km² in mangrove areas. From the analysis of the change detection, it was observed a total increase of 684.55 km², a reduction of 411.7 km² and an unchanged area of 2213.70 km² of mangrove. The classification was validated through statistical analysis of two error matrices (2008 and 2016). The 1996 error matrix presented overall accuracy = 0.92; Kappa index = 0.84; and Tau index = 0.84. For the year 2016, overall accuracy = 0.93; Kappa index = 0.85; and Tau index = 0.85. On the other hand the error matrix for change detection showed an overall accuracy of 78.43%, with a quantity disagreement of 11.86% and an allocation disagreement of 9.71%. Quantifications of mangrove loss was 414 ± 43 km², gains was 590 ± 48 km² and remained mangrove unchanged was 2305 ± 60.3 km². These results demonstrate the effectiveness of using object-oriented classification for mapping and analyzing mangrove dynamics on a large scale. The products obtained in this research can serve as a basis for future work on the dynamics of mangroves, contributing to the improvement of management and preservation of this important ecosystem.
Acesso aberto (Open Access)
Hidrodinâmica e transporte de sedimentos em uma área de manguezal na planície costeira de Bragança, Amazônia Oriental – Brasil
(Universidade Federal do Pará, 2012-10-04) MIRANDA, Artur Gustavo Oliveira de; ROLLNIC, Marcelo; http://lattes.cnpq.br/6585442266149471; SOUZA FILHO, Pedro Walfir Martins e; http://lattes.cnpq.br/3282736820907252
The physical processes that occur in intertidal areas are essential for the existence of mangrove ecosystem, due process interaction between oceans and estuaries, with mangroves. The tidal channels represent the most important and peculiar features of coastal environments, due your circulatory system basics which controls both the tidal flow as the channel morphology. This paper presents a set of data to analyze and understand the hydrodynamic process and sediment dynamics in the coastal plain of Bragança, specifically the region known as Furo do Meio tidal channel. At this region were carried out topographic and hydrodynamic collection of data, physicochemical properties of water measurements, surficial sediment collection, and quantification of sedimentation rate according the seasonality pattern (March, July, September and December). As this study demonstrated, the tidal channel presented a well defined bidirectional flow, though the area vegetated by mangrove presented a turbulent flow, so the variation of current speed in both morphological units vary according to seasonality. The average concentration of suspended solids (CSS), between the months from March to September, remained at around 400 ppm in the channel. To the tidal flat dominated by mangrove forest, an average of approximately 21,000 ppm was obtained, while in the month of December, these values were lower than those recorded in previous months, where the maximum CSS in the channel was around 270 ppm and in the mangrove was 1000 ppm. There was not a direct relationship between the CSS and the mangrove channel, where high CSS in the mangrove is associated with the remobilization of the sediment itself at tide input in this area; there was not a significant sedimentary input of mangrove to the channel. Changes in topographical elevation corroborates the values obtained in measurements of trappers and the variation of sedimentary textural classes between fine silt and fine sand are associated with the seasonal hydrodynamic variation.
Acesso aberto (Open Access)
A influência dos parâmetros biofísicos da vegetação de mangue em regeneração no retroespelhamento de imagens radarsat-2 multipolarizada na Amazônia, Brasil
(Universidade Federal do Pará, 2013-09-05) COUGO, Michele Ferreira; SILVA, Arnaldo de Queiroz da; http://lattes.cnpq.br/1682623730626187; SOUZA FILHO, Pedro Walfir Martins e; http://lattes.cnpq.br/3282736820907252
The main goal of this work is to understand the relationship between backscattering (σ°, β° e γ) of a multipolarized Radarsat-2 Fine Beam band C image with biophysical parameters of mangrove vegetation in regeneration. The study site was the Bragança peninsula (northeast of Pará State) far from the Amazon River mouth about 380 km (southeast). 30 years ago it was built a highway causing disturbances in the hydrological regimes and vegetation death, then it was deforested and currently the natural regeneration is incipient. Field data was taken in 17 stands of 10 square meters and it was delimited and positioned with a DGPS (Differential Global Positioning System) and a total station. Structural characterization of the sampling units was made with the following field data: CBH (circumference at breast height), height and specie in 3090 specimen and then it were estimated values of DBH (diameter at breast height) and BA (basal area). A cluster analysis of the sample units has defined four groups of vegetation in different regeneration stages: pioneer stage, initial regeneration, intermediate regeneration and advanced regeneration. Fromard et al. (1998) equation was used to biomass estimation. It was used a SLC (Single Look Complex) multipolarized image (Radarsat-2) from June 11th, 2010. VIMAGE/Focus/PCI software was used to retrieve backscattering values of SAR (Synthetic Aperture Radar) image, using as reference the limits of the parcels. Statistical models of simple and multiple regressions were used in the analysis of the relationship between vegetation structure and backscattering values of the SAR image. Results shown that linear sigma backscattering with cross-polarization (VH) had the strongest relationship with all vegetation structure analyzed. Although the function of multiple linear regression with HH, VH and VV polarization got the best adjustments with the biophysical parameters mean height, DBH and Biomass (R2 values were respectively 0,81, 0,79 and 0,79). Backscattering values of the image with adjusted functions were used to generate maps of these three biophysical variables and it was coherence with field data, mainly mean height and DBH maps. Biomass map got a low amplitude variation suggesting saturation of the sign, in mangroves in regeneration, less than indicated in the literature to band C in homogeneous mangrove areas.
Acesso aberto (Open Access)
Mapeamento das unidades de paisagem, da sensibilidade ambiental e da vulnerabilidade social na área do Porto de Itaqui-Bacanga, Ilha de São Luís, MA
(Universidade Federal do Pará, 2008-02-27) ANDRADE, Milena Marília Nogueira de; SOUZA FILHO, Pedro Walfir Martins e; http://lattes.cnpq.br/3282736820907252
Almost 30% of the Maranhão State population live in the coastal zone, which has several services and human activities, with emphasizes to harbor actions darried out in the Itaqui harbor. The main hazard related to this activitie is associated with oil spill, due to cleaning, saving and transportation processes. The aim of this work is map the environmental sensitivity index of de landscape units, as well as the social vulnerability of the residencial area under harbor influence. This will provide information about the priority areas to contingency and recovery. High resolution remote sensing, digital cartography and social-economic data were collected and analyzed from a Geografical Information System. At first, the social-economic data were analyzed from descriptive statistic and through correspondance analisys. After that, three variables were chosen (fisinhg relationship, schooling and incoming) to generate the Compose Vulnerability Index (CVI), used to produce the social vulnerability map. As result, 4 landscape domains and 21 landscape units were recognized, as well as, their Enviromental Sensitivity Índex (ESI): Coastal Plateau (Flat high land,, Active cliff line – ESI 3B, Inactive cliff line – ESI 8A, Abrasion platform – ESI 1C, Intermittent lakes); Coastal Plain (Estuarine channel, Mangroves – ESI 10D, Tidal sandflat and Sandy/muddy banks – ESI 7, Sheltered scarps in sedimentary rocks (paleocliffs) – ESI 8A, Tidal mudflat – ESI 9A, Vegetated tidal mudflat – ISA 9B); Coastline plain (Beach – ESI 3A, Scarps and steep slopes in sand -3B, Paleodunes); e Human System (Urban areas, , Military Area, Artificial Lakes and Atificial Strutures – ESI 1B). Through the Correspondance Analisys it was possible recognize the relatitionships between Fisnhig relationship vs. Neiborhood, and Scoolhing vs. Income variables. Meanwhile, the social-economic analysis when carried out in the GIS allowed the social vulnerability map construction. This map showed that the high vulnerability areas are the neiborhoods: Vila Nova (Ponta do Bonfim), Alto da Esperança (Tamancão) e Alto da Esperança (Residencial Ana Jansen); these ones are built in lower topografic places, which are subject to floods. Their occupation are more recent, and the people that lives there has direct relationship with fishing, low incoming and low schooling. In the other hand, the place classified as low vulnerability is represented by Anjo da Guarda Neiborhood that its located along the José Sarney Avenue, which is topographically higher, and its occupation is marked by people with high income, high scooling and lower relationhip with finshing. Therefore, it is possible to conclude that high social vulnerability areas are located in the boundary of the coastal plain, in contact with mangroves (ESI 10D), where the fishing activities area essential as social tradition and income generation.
Acesso aberto (Open Access)
Mapeamento dos parâmetros florísticos e estruturais de floresta de mangue com dados LIDAR e SRTM
(Universidade Federal do Pará, 2014-06-24) ABREU, Maria Rafaela Braga Salum de; FERNANDES, Marcus Emanuel Barroncas; http://lattes.cnpq.br/8943067124521530; SOUZA FILHO, Pedro Walfir Martins e; http://lattes.cnpq.br/3282736820907252
This study estimated the floristic and structural parameters (height, diameter at breast height - DBH and biomass) of mangrove from remote sensing data Laser Detection and Range (LIDAR), Shuttle Radar Topography Mission SRTM and orthophoto on Guarás Island, located 30 km from the mouth of the Amazon River. It was used data from LIDAR, SRTM and ortophotos during overflights. With the orthophoto data it was produced a map of Geobotanic units including only the mangrove area. It was performed the orthometric height correction and the point clouds was interpolated by nearest neighbor Technique, generating Digital Elevation Model (DEM) LIDAR (full points) with RMSE of 0.88 cm and using a computer language it was statistically separated the information of the last pulse of the surface as known as ground points. Thus data was interpolated by kriging method which was subsequently subtracted from the DEM. With Digital Model Height (DMV) values it was defined and selected the study sites and it was measured the trees in three categories: upside, intermediate and emerging trees. Than it was measured DBH and height in these places. 212 samples were collected and it was calculated the RMSE between the heights of the LIDAR and field, that resulted in a RMSE of 1.10 m. The chosen model to cross the information of LIDAR and field was the linear model whit R 2 = 91% and RMSE = 0.98 cm and for DBH and height field it was chosen the logarithmic model with R 2 = 74.1%. In the results of calibration of SRTM data the logarithmic model was also the most appropriate, in the relation of average height with SRTM there was a R 2 = 91% and RMSE of 2.2 m and to avarage DAP with SRTM the R 2 value was 88% and RMSE of 2.2 cm. With an inventory, biomass per specie data was estimated from field and it was produced maps of biomass per species from LIDAR, corrected SRTM and ortophotos.
Acesso aberto (Open Access)
Morfologia e análise da sucessão deposicional do vale inciso Quaternário de Marapanim, Norte do Brasil.
(Universidade Federal do Pará, 2009-11-03) SILVA, Cléa Araújo da; SOUZA FILHO, Pedro Walfir Martins e; http://lattes.cnpq.br/3282736820907252; 3282736820907252
The coastal sector located eastward of the Amazon river mouth is characterized by several estuarine systems, that harbor large mangrove areas with approximately 7600 km2. The Marapanim Estuary is influenced by macrotidal regime with moderate waves influence. The morphological and morphostratigraphic aspects were investigated by using remote sensing images (i.e., Landsat-7 ETM+, RADARSAT- 1 Wide and SRTM) integrated with bathymetric and surface sediments data. Facies analysis of quaternary deposits was studied based on cores collected by vibracore and rammkersonde systems. These deposits were dating by AMSradiocarbon. The estuary was compartmentalized into estuary mouth, estuary funnel, and upstream estuary. The open-mouthed estuary (inner, middle and outer) is influenced by a mixedenergy in which both waves and macrotides play an important role in the hydrodynamic control, and transport and sediment. The data integration reflects an evolutive model of estuarine incised valley fill, defined by a basal surface that limits Quaternary deposits from Tertiary one, which are recovered by fluvial sands that constitute the lowstand system tract. The initial stage of the last transgression provided the trapping of fluvial sediments within the valley. Later, a transgressivemud deposits migrated over fluvial sediments to landward. Under stillstand sea level occurs widedevelopment of mud flat (freshwater swamp and mangroves), as well as its progradation toward the estuary mouth. Also, occur a transgressive pulse responsible for sandy deposits (beaches and dunes) that recover muddy deposits and provide the migration of this deposit to the elevated topographic level. The geological model proposed has application for the northeast coast of Pará, characterized by estuarine systems resulted by the last Holocene transgression.
Acesso aberto (Open Access)
Morfologia e sedimentação em um estuário de macromaré e plataforma adjacente, margem equatorial brasileira
(Universidade Federal do Pará, 2025-06-30) MIRANDA, Artur Gustavo Oliveira de; SOUZA FILHO, Pedro Walfir Martins e; http://lattes.cnpq.br/3282736820907252; https://orcid.org/0000-0003-0252-808X
Understanding morphosedimentary dynamics in macrotidal estuaries is a challenging task, particularly in large-scale systems where seabed morphology and sediment distribution are poorly constrained. This study presents an unprecedented investigation into the morphological changes and the spatial and seasonal variability of surface sediments in the São Marcos Estuary and its adjacent continental shelf. The objective was to assess multidecadal morphobathymetric evolution (1977–2022) and short-term sedimentary pattern modifications associated with climatic seasonality, characterized by a dry season and a rainy season (2020–2021). The 45-year analysis, based on comparisons of nautical charts, revealed a sediment transport pattern primarily controlled by ebb currents, which governs the evolution of key morphological features. A highly deflected subaqueous delta, developed in a marine environment dominated by macrotidal oceanographic processes, was identified on the inner continental shelf—this configuration deviates markedly from classical models of tidedominated deltas. The estuary exhibited morphological instability in the area seaward of the estuarine funnel—proximal to the São Luís Port Terminal—while the region landward of the funnel, including the lower estuary and the inner continental shelf, displayed relative morphological stability. Sediment budget analyses indicated a clearly negative sediment balance for both environments over the study period. The estuary experienced a net volume increase of 1.1 × 10⁹ m³, equivalent to 2.91 × 10¹² tm⁻³ of eroded sediments, with estimated erosion rates of 6.4 × 10¹⁰ tm⁻³/year and a volumetric erosion rate of 2.4 × 10⁷ m³/year. Similarly, the inner continental shelf recorded a net volume increase of 1 × 10⁹ m³, corresponding to 2.65 × 10¹² tm⁻³ of eroded sediments, with annual rates of 2.2 × 10⁷ m³/year for volume and 5.9 × 10¹² tm⁻³/year for sediment mass. Together, both environments accounted for a total net volume increase of 2.1 × 10⁹ m³, representing a total of 5.56 × 10¹² tm⁻³ of eroded sediments, with combined net erosion rates of 4.6 × 10⁷ m³/year and 1.23 × 10¹¹ tm⁻³/year, respectively. Sediment budget calculations across isobaths showed that the estuary experienced substantial sediment losses down to the -30 m isobath. Below this depth, however, sediment behavior was inverse, indicating sediment retention or accumulation. In contrast, the inner continental shelf exhibited a significant net volume increase up to the -25 m isobath, followed by a depositional regime with attenuated sediment accumulation down to the -45 m isobath. For sedimentary deposit characterization, 284 surface sediment samples were collected during the dry season and 281 during the rainy season. These samples were analyzed and spatially interpolated to quantify the percentages of mud (silt and clay), sand, organic matter, and calcium carbonate in both seasonal periods. Textural classifications of surface sediments were assigned based on the schemes proposed by Wentworth (1922), Shepard (1954), and Larsonneur (as modified by Dias, 1996). During the dry season, estuarine sediments were predominantly composed of fine and medium sand, while the adjacent continental shelf was mainly composed of medium sand. Sand accounted for approximately 70% of all dry season samples. In the rainy season, the estuary maintained a similar sediment distribution, with sand again dominant—fine sand being most abundant, followed by medium sand. The adjacent shelf showed a predominance of fine and medium sand, indicating that climatic seasonality exerted influence primarily over the continental shelf region. The intense tidal activity within the study area is the principal driver of the morphosedimentary dynamics of the São Marcos Estuary and its adjacent continental shelf.