Navegando por Assunto "Remote sensing"

Agora exibindo 1 - 18 de 18

Acesso aberto (Open Access)
Uma abordagem híbrida e semiautomática para estimativa de regiões cobertas por nuvens e sombras em imagens de satélite: análise e avaliação
(Universidade Federal do Pará, 2014-03-31) SOUSA, Danilo Frazão; PELAES, Evaldo Gonçalves; http://lattes.cnpq.br/0255430734381362
The main goals of this work are to propose a more automatic and efficient algorithm to replace regions of clouds and shadows in satellite images as well as an index of reliability that is previously applied to each image, in order to measure the feasibility of the estimation of the regions covered by atmospheric components using that algorithm. The motivation comes from the problems caused by these atmospheric elements, among them: to impede the identification of objects of the image, to make the urban and environmental monitoring more difficult, and to interfere in crucial stages of digital image processing to extract information for the user, such as segmentation and classification. Through a hybrid approach is proposed a method for decomposing regions using a median non-linear low-pass filter, in order to map the regions of structure (homogeneous) and texture (heterogeneous) in the image. In these areas was applied restoration methods Inpainting by Smoothing based on Discrete Cosine Transform (DCT), and Exemplar-Based Texture Synthesis, respectively. It's important to note that the techniques have been modified to be able to work with images obtained through of satellite sensors with peculiar features such as large size and/or high spectral variation. Regarding to the reliability index, it aims to analyze the image that contains atmospheric interference and hence estimate how much reliable will be the redefinition, based on the percentage of cloud cover over the regions of texture and structure. This index is composed by combining the result of supervised and unsupervised algorithms involving three metrics: Average of Accuracy Global, Measure Of Structural Similarity (SSIM) and Average of Pixels Confidence. Finally, it was verified the effectiveness of these methods through a quantitative assessment (provided by the index) and qualitative (the images resulting from processing), showing the possible application of the techniques to solve the problems that motivated this work.
Acesso aberto (Open Access)
Análise espaço-temporal dos manguezais degradados de Bragança, com base em imagens de satélite e modelos de elevação digital
(Universidade Federal do Pará, 2022-02-22) MOLANO CÁRDENAS, Sergio Mauricio; COHEN, Marcelo Cancela Lisboa; http://lattes.cnpq.br/8809787145146228
The Bragança Peninsula occurs at the northern littoral of Brazil, in the state of Pará. It is characterized by the largest continuous mangrove belt in the world. The construction of the PA- 458 road in the ‘70s changed the hydrodynamics of the peninsula, causing the degradation of a considerable portion of the mangroves in the central region of the peninsula. Recently, degraded areas are being colonized by mangrove trees, mainly by the Avicennia germinans specie. This study intends to identify changes in the degraded areas of the tidal flats in topographically higher sectors during the last 35 years. To reach that objective, we used the following techniques: a) manual mapping of the degraded areas with mid spatial resolution satellite imagery; b) object-based classification of the degraded areas and mangrove species, using high spatial resolution satellite imagery; c) photogrammetry of drone imagery; d) digital elevation models; and e) topographic validation with theodolite and GNSS GPS “Antenna Catalyst”. From 1986 to 2019, there was a reduction in the degraded areas of 247.96 ha according to the mid-resolution “dataset” quantification. However, high-resolution data showed a reduction in the degraded areas of 211.65 ha between 2003 and 2019. The degraded areas quantification presents fluctuations in the regeneration trend; it is related to significant climatic phenomena such as “El Niño” and “La Niña”, accompanied by periods of drought and high rainfall, respectively. Overall accuracy and Kappa index values for the high-resolution data generally exhibited values above 0.9. Producers’ and users’ accuracy and Kappa per class values showed the difficulties separating mangrove species due to the lack of radiometric resolution of the analyzed images. The digital terrain model representing the tidal flat showed two topographically differentiated regions in the degraded areas, separated by the PA-458 road, which are mainly influenced by the Caeté’s and Taperaçú’s characteristics. This same difference was found in the vegetation height model, where the largest trees are located toward the SE side of the road, reaching 25 m, while at the NW side of the road, the tree heights oscillated mainly between 5 and 15 m. The sea-level rise specifically controls regeneration rates. This relocated the intertidal zone to topographically higher areas, increasing tidal flushing processes, essential for the mangrove forests development.
Acesso aberto (Open Access)
Análise temporal da cobertura vegetal de um fragmento da RPPN Seringal Triunfo, Ferreira Gomes - Amapá
(Universidade Federal do Pará, 2021-12-27) SCHNEIDER, Juliana Cristina; GODOY, Bruno Spacek; http://lattes.cnpq.br/4036516695601666; https://orcid.org/0000-0001-9751-9885
The construction of dams became necessary for national development, the Amazon region, for having a great hydro-energetic potential, was also used for the construction of these projects. River Araguari's hydrographic basin has three hydroelectric dams (Coaracy Nunes, Ferreira Gomes and Cachoeira Caldeirão) built in its middle course, in the municipality of Ferreira Gomes, however the construction generated several problems, such as loss of territoriality, difficulties in subsistence of villages and the environment modification. However, in 1998, there was the enactment of the Seringal Triunfo National Heritage Private Reserve, which aims to conserve biodiversity. Therefore, there is a need for studies aimed at improving the knowledge of vegetation cover, which have occurred since the enactment of the RPPN. In this sense, the present study sought to understand whether there were changes in the vegetation cover in the RPPN from 2000 to 2015, after its approval and with the construction of UHE Ferreira Gomes and Cachoeira Caldeirão. For this, remote sensing data were used. Twelve images obtained from the TM/Landsat-5, ETM+/Landsat 7 and OLI/Landsat-8 satellites were used, delimiting the study area with the creation of two polygons (buffer), one located within the RPPN and another adjacent with approximately the same size. Digital processing techniques were applied to these images with the aid of pixel counting software. The Normalized Difference Vegetation Index (NDVI) was calculated, making it possible to obtain the median. The obtained results show that the image processing allowed differentiate its constituent elements (vegetal cover and exposed soil). The calculation of the NDVI medians, for the scenes between the years 2000 to 2015, in the area located within the RPPN ranged from 0,37 to 0,64 and the medians of the adjacent area ranged from 0,29 to 0,63, thus, the statistical analysis showed no relationship with the years (F1,10 = 0,02 and P = 0,87), indicating that during the analyzed period there was a stability in the vegetation cover, the same occurred for the adjacent area (F1,10 = 0,11 and P = 0,74). This stability in the area of the RPPN may be related to the role it plays in nature conservation and in the adjacent area to the stagnation of population growth in the municipality. The use of images from remote sensors proved to be a very valuable tool for the present research, even without carrying out an on-site visit, it was possible to calculate the NDVI. Therefore, it is recommended for future work to analyze the NDVI from years prior to 2000, that is, years prior to the approval of the RPPN, as well as on-site visits, for the validation of the components observed in the NDVI, for the NDVI classification to the studied locality.
Acesso aberto (Open Access)
Análise temporal do índice de vegetação e caracterização da cobertura vegetal no Estuário amazônico
(Universidade Federal do Pará, 2021-09-09) RIBEIRO JUNIOR, Julia Pereira; CATTANIO, José Henrique; http://lattes.cnpq.br/1518769773387350; https://orcid.org/0000-0001-8335-9593
This study was carried out from 1990 to 2020 in the insular region of Baia do Guajará, state of Pará and aimed to analyze the dynamics of land use and cover on the islands of the insular region of Baia do Guajará through the NDVI vegetation index. with the intention of provoking the discussion and insertion of new urban, economic, social and tourist development strategies in the region in the APA of Ilha do Combú, located in the municipality of Belém, Pará. To achieve this objective, the script to generate vegetation index (NDVI) was prepared in the code editor of Google Earth Engine, comparing it with the monthly and annual averages of rainfall. It was found that seasonality consistently influences the behavior of vegetation and, consequently, the NDVI, since anthropic changes were minimal on most islands.
Acesso aberto (Open Access)
Caracterização dos padrões morfodinâmicos em cristas de praias na costa amazônica
(Universidade Federal do Pará, 2023-09-29) ROSÁRIO, Edineuza dos Santos; SANTOS, Valdenira Ferreira dos; http://lattes.cnpq.br/1395198888623953; HTTPS://ORCID.ORG/0000-0002-5038-4191; RANIERI, Leilanhe Almeida; http://lattes.cnpq.br/3129401501809850; https://orcid.org/0000-0002-9870-4879
Knowledge of beach environments requires an integrated morphodynamic approach using different spatio-temporal scales, in order to understand the role of coastal and marine processes in modifying beach morphology. There are some important peculiarities about these processes on the beaches of the Amazon region, such as the large hydro-sedimentary discharge from the estuaries, high rainfall rates and the high amplitude and intensity of the tidal currents, which shape the often complex beach systems, such as beach ridges. The objective of this research was to analyze the morphological dynamics of a beach ridge segment located north of the mouth of the Amazon River, in Goiabal (city of Calçoene), in the coastal ocean sector of the state of Amapá.The hypothesis is that the morphological changes in the segment of beach crest under study are influenced by the hydrosedimentary dynamics of the Amazon River. The research methodology was based on three stages: (1) determining the morphology of beach ridges and their changes (beach profile variation, sedimentary deposits and beach classification); (2) analysis of morphosedimentary processes (physical coastal agents such as tides, waves and currents, and sediment supply such as sediment plumes; (3) data integration (correlation between the processes analyzed in stage one and two). The results indicate significant average variations in the morphosedimentation of the Goiabal beach ridge system, with seasonal migration (~24 to ~42 meters) towards the mainland. Erosion and deposition on the ridges and subsequent channels averaged less than 0.30 m along the beach profiles during the seasonal cycle. The oceanographic parameters indicate an average wave height of 0.25 m and an average tidal range of 5 m. Coastal currents are directed west-southwest and there is a predominance of ebb tide currents during the rainy season. The sediment plume of the Amazon River was closer to the study area during the rainy season (~15 to 25 km), with a predominance of ebb tide currents. Thus, it can be concluded that the segment of beach crest studied has a greater influence from the Amazon River sediment plume during the rainy season, intensifying the deposition of fine sediments. The displacement of beach ridges and the supply of sediment have a strong relationship with tidal dynamics in the region.
Acesso aberto (Open Access)
Classificação de regiões de desmatamento via imagens do satélite landsat no nordeste do Pará
(Universidade Federal do Pará, 2023-12-18) CANAVIEIRA, Luena Ossana; COSTA, João Crisóstomo Weyl Albuquerque; http://lattes.cnpq.br/9622051867672434
Acesso aberto (Open Access)
Danos socioambientais da dendeicultura na microrregião de Tomé-Açu, PA.
(Universidade Federal do Pará, 2024-04-29) MONTEIRO NETO, Albertino; NAHUM, João Santos; http://lattes.cnpq.br/9009465125001273
Oil palm cultivation is a spatial process fostered by actions between the State and the business sector, enabling the expansion of oil palm cultivation in the Amazon. As a research focus, we argue that oil palm cultivation emerges as a central activity in monoculture expansion in the Amazon, bringing a series of socio-environmental damages, especially in the Tomé-Açu Microrregion (MRTA). The research consists of a multifaceted analysis, from the historical context and set of laws that facilitated the expansion of oil palm plantations, to the application of advanced geoprocessing techniques and remote sensing to detect and understand changes in land cover and land use. Thus, the general objective is to understand the expansion of oil palm cultivation as a source of socio-environmental damages in the Tomé-Açu Microrregion, PA. The chapters of this dissertation were written in the format of scientific articles, corresponding to chapters 2, 3, and 4. The study area is the Tomé-Açu Microrregion, in northeastern Pará, and we used the Arauaí settlement and the Jambuaçu quilombola territory as clipped portions from the study area. The methodology consisted of literature review, supervised classification of satellite images, and field visits to communities impacted by oil palm cultivation. We perceive the persistence of the discourse promising economic and social integration of rural areas adapted to oil palm cultivation. There is no room for discussion of alternative proposals for rural economic integration, nor is the peasant way of life considered in the conception of integration projects. Geoprocessing techniques proved to be efficient in identifying oil palm plantations and detecting deforestation associated with the expansion of oil palm monocultures. Between 1988 and 2023, 32,322 hectares of forests (primary and secondary) were converted into oil palm plantations in the MRTA. Family farmers associated with the production chain are irreversibly linked to oil palm cultivation. Residents of Jambuaçu suffer from pressure on the territory caused by industrial oil palm cultivation.
Acesso aberto (Open Access)
Danos socioambientais da dendeicultura na microrregião de Tomé-Açu, PA
(Universidade Federal do Pará, 2024-04-29) MONTEIRO NETO, Albertino; NAHUM, João Santos; http://lattes.cnpq.br/9009465125001273; https://orcid.org/0000-0001-7791-9240
Oil palm cultivation is a spatial process fostered by actions between the State and the business sector, enabling the expansion of oil palm cultivation in the Amazon. As a research focus, we argue that oil palm cultivation emerges as a central activity in monoculture expansion in the Amazon, bringing a series of socio-environmental damages, especially in the Tomé-Açu Microrregion (MRTA). The research consists of a multifaceted analysis, from the historical context and set of laws that facilitated the expansion of oil palm plantations, to the application of advanced geoprocessing techniques and remote sensing to detect and understand changes in land cover and land use. Thus, the general objective is to understand the expansion of oil palm cultivation as a source of socio-environmental damages in the Tomé-Açu Microrregion, PA. The chapters of this dissertation were written in the format of scientific articles, corresponding to chapters 2, 3, and 4. The study area is the Tomé-Açu Microrregion, in northeastern Pará, and we used the Arauaí settlement and the Jambuaçu quilombola territory as clipped portions from the study area. The methodology consisted of literature review, supervised classification of satellite images, and field visits to communities impacted by oil palm cultivation. We perceive the persistence of the discourse promising economic and social integration of rural areas adapted to oil palm cultivation. There is no room for discussion of alternative proposals for rural economic integration, nor is the peasant way of life considered in the conception of integration projects. Geoprocessing techniques proved to be efficient in identifying oil palm plantations and detecting deforestation associated with the expansion of oil palm monocultures. Between 1988 and 2023, 32,322 hectares of forests (primary and secondary) were converted into oil palm plantations in the MRTA. Family farmers associated with the production chain are irreversibly linked to oil palm cultivation. Residents of Jambuaçu suffer from pressure on the territory caused by industrial oil palm cultivation.
Acesso aberto (Open Access)
Dinâmica da cobertura florestal a partir de análises realizadas em áreas de extração seletiva de madeira no Estado do Pará
(Universidade Federal do Pará, 2023-09-29) ROCHA, Nívia Cristina Vieira; GALBRAITH, David; http://lattes.cnpq.br/2145475131329843; ADAMI, Marcos; http://lattes.cnpq.br/7484071887086439; https://orcid.org/0000-0003-4247-4477
The selective logging in the Amazon region is an activity that holds relevance in social, economic, and environmental aspects. In many cases, this is considered a low environmental impact activity in the forests when compared to deforestation. This research assessed canopy opening in selectively logged areas in Eastern Amazon over different years with reduced impact. Detailed monitoring was conducted in these areas using both hemispherical images and orbital images to evaluate the persistence of impacts over time. Hemispherical photographs were used to measure canopy opening and provide a high-resolution assessment of the logged areas. This study also utilized images obtained from Landsat, Sentinel, and Planet satellites. Spectral Mixture Analysis and enhancement techniques were applied to these orbital images to detect canopy opening impacts caused by selective logging. Hemispherical images revealed that even 17 years after the logging activities ceased, the impacts caused by selective logging were still discernible. Meanwhile, orbital images allowed for the identification of logging at different time intervals depending on their respective resolutions. From the results, this study highlights the importance of the combined use of hemispherical and satellite images to monitor the effects of selective logging over time in the Amazon. This enables a more comprehensive understanding of forest dynamics, the persistence of impacts, and the importance of continuous monitoring in logged areas to assess long-term effects and adopt sustainable management strategies.
Acesso aberto (Open Access)
Dinâmica temporal da cobertura vegetal da Comunidade Água Fria na RDS Alcobaça em Tucuruí-PA
(Universidade Federal do Pará, 2021-12-27) SILVA, Renata Albuquerque da; GODOY, Bruno Spacek; http://lattes.cnpq.br/4036516695601666; https://orcid.org/0000-0001-9751-9885
The Tucuruí Hydroelectric Power Plant has great socioeconomic and environmental importance for the southeast region of Pará, due to the formation of its artificial lake, resulting in changes in vegetation cover and loss of biodiversity. This study seeks to understand the dynamics of change in vegetation cover that occurred in the Água Fria Community, RDS Alcobaça, after the filling of the Tucuruí Reservoir, making it possible to understand the changes resulting from deforestation and subsidize proposals for interventions. Digital Image Processing (PDI) techniques were used, divided into stages: Landsat 8, Landsat 7 and Landsat 5 image acquisition; combination of spectral bands (Band 3 and Band 4) and atmospheric correction; NDVI calculation, map production and statistical analysis. To obtain the orbital images, the U.S.G.S. digital platform was used, in the months of July, August and September, from 1990 to 2020, with intervals of two years. The NDVI value showed no relationship with the years, indicating that during the years analyzed there was no significant reduction in the vegetation cover on the ground in the Água Fria community, in the Alcobaça RDS.
Acesso aberto (Open Access)
Os efeitos dos manguezais e das intervenções humanas na dinâmica sedimentar das praias de SalinópoliS, PA
(Universidade Federal do Pará, 2025-03-07) PÉREZ MARTINEZ, Julián David; COHEN, Marcelo Cancela Lisboa; http://lattes.cnpq.br/8809787145146228
Salinópolis, on the coast of Pará, has become an important tourist hub, expanding its infrastructure along the coastal zone. This area is considered sensitive to sea-level rise. Therefore, identifying the area most vulnerable to coastal erosion is extremely important, especially due to the growth of coastal urban areas, which can interfere with sediment balance, intensifying erosion processes. This master's thesis aims to identify the effects of mangroves and coastal urban expansion on sediment balance along the beaches of Salinópolis. This study was carried out through a spatio-temporal analysis based on satellite (2003 – 2023) and drone data (2019-2024). The data revealed that the urban area expanded (627 ha), while the mangrove area fluctuated, increasing from 3630 ha to 3889 ha between 2003 and 2023. Erosion was identified along the beaches, particularly at Praia do Farol Velho (erosion = 432,625 m³, sedimentation = 217,259 m³). Praia do Atalaia (erosion = 115,415 m³, sedimentation = 462,630 m³) and the Maçarico/Corvina beaches (erosion = 640,389 m³, sedimentation = 801,670 m³) showed a trend of sediment accumulation. Erosion has predominantly occurred in the lower intertidal zone, while sedimentation has occurred in the supratidal zone and the upper intertidal zone. Residences, particularly in Farol Velho, may accentuate this process and Praia do Atalaia, which are currently located in the intertidal and supratidal zones in front of the mangroves. The walls built to protect these residences from waves and current action have also functioned as a barrier to retain sediments at the upper intertidal/supratidal transition. In much of Praia do Farol Velho, without these walls, there has been erosion in the intertidal zone, with a retreat of the coastline by about 100 meters between 2009 and 2023. However, the Maçarico/Corvina beaches have mangroves in front of the urban infrastructure, with sediment accumulation predominantly in the supratidal zone and the upper part of the intertidal zone. Human interventions on these beaches have not impacted the sedimentary dynamics until 2023. This beach provides a good example of how coastal infrastructure projects should be planned, using mangroves as protection against the action of waves and currents. However, the construction of beach access walkways in 2024 altered the hydrodynamic flow of a tidal channel, trapping tidal waters and creating muddy intertidal zones with porewater salinities close to 70 ‰. This process has already killed approximately 7 ha of mangrove. These data provide valuable insights to guide more efficient public and private investments, avoiding construction in high-risk areas or those that harm the mangroves, offering crucial information about coastal erosion and its impacts on urban infrastructure in the beaches of Salinópolis, especially in the face of sea-level rise.
Acesso aberto (Open Access)
Estimation of above-ground forest biomass in Amazonia with neural networks and remote sensing
(Universidade Federal do Pará, 2009-03) ALMEIDA, Arthur da Costa; BARROS, Paulo Luiz Contente; MONTEIRO, José Humberto Araujo; ROCHA, Brigida Ramati Pereira da
This paper proposes an integrated methodology for estimating aboveground forest biomass in Amazon region. It is based on remote sensing, artificial neural networks and geographical information systems technologies for achieving confident results with a lesser cost than traditional methods of forest inventory. This methodology was tested and validated in Tucurui Reservoir, Brazil.
Acesso aberto (Open Access)
Evolução multitemporal (2010-2024) do canal de acesso do estuário do rio Amazonas (canal Norte - baía de Macapá - margem ocidental)
(Universidade Federal do Pará, 2025-02-27) SILVA, Eduardo Pantoja da; EL-ROBRINI, Maâmar; http://lattes.cnpq.br/5707365981163429; https://orcid.org/0000-0001-7850-1217
The Amazon River, the world’s largest by water volume, has an average discharge of approximately 209,000 m³/s and exhibits a semidiurnal tidal range that varies from 0.3 m to 4 m during spring tides. Its vast watershed profoundly shapes the geomorphology of the Amazon Basin, driving sedimentary processes and directly affecting navigability. The economic importance of navigation within its estuary contrasts sharply with the challenges posed by both natural and anthropogenic alterations, which compromise the long-term stability of the channel. This dissertation analyzes the geomorphological evolution of the Amazon River’s northern channel and Macapá Bay from 2010 to 2024. It assesses the impacts of sedimentary dynamics on navigability and port management. The research methodology encompassed the analysis of bathymetric data, 38 Sentinel-1 radar scenes (captured between 2016 and 2024) processed via the Google Earth Engine platform, and historical hydrological records. Bathymetric processing was carried out in SURFER using the kriging method, while spatial analyses were performed with geostatistical tools in Python and QGIS. This included the delineation of sandbanks and the calculation of modification areas to identify erosion and deposition patterns. The study area is highly dynamic, influenced by tidal forces, river discharge, and sedimentation. These interacting processes drive the formation and migration of sandbanks and unstable channels, which directly affect bed depth and navigational safety. The findings indicate a reduction in the northern channel’s average depth from 26 m to 22 m, along with a noticeable east-northeastward migration. This shift is evidenced by erosion along the left bank and simultaneous deposition on the right bank. Three-dimensional analysis revealed that while the bed morphology was relatively homogeneous in 2011, by 2024 it had become more compartmentalized, reflecting a rate of change of 0.307 m per year. The study also highlights significant variations in the spatial extent of emerged areas within Macapá Bay. During El Niño years (2016, 2018, 2023), average accretion reached 8,326.93 km², whereas La Niña years (2017, 2020, 2021, 2022) experienced average erosion of -13,941.27 km². Linear regression analysis produced an adjusted R² value of 0.163, indicating that hydrological variability and human activity influence the region’s sedimentary dynamics. The observed geomorphological changes directly affect waterway management and the Santana port complex, underscoring the need for effective strategies to ensure ongoing navigability. Remote sensing has proven invaluable for monitoring these dynamic transformations, offering strategic insights to enhance port infrastructure planning and ensure the long-term sustainability of navigation in the region. This research reinforces the necessity of continuous monitoring and integrated hydrodynamic planning to maintain navigational safety and logistical efficiency. The combined use of geoprocessing and bathymetric techniques enables more accurate planning and the implementation of measures to mitigate sedimentation impacts, thereby preserving the viability of inland waterway transport. Ultimately, the results provide essential support for managing navigation in the Amazon River’s northern channel, promoting enhanced efficiency and safety.
Acesso aberto (Open Access)
Histórico do uso da terra e composição de gerromorpha (insecta: subordem heteroptera) em igarapés da Transxingu
(Universidade Federal do Pará, 2024-02-28) COSTA, Iluany da Silva; SILVA, Karina Dias da; http://lattes.cnpq.br/2271768102150398; https://orcid.org/0000-0001-5548-4995
The Amazon Forest faces threats due to the increasing exploitation of natural resources driven by the economic growth of the region, intensified since the exploitation of rubber between 1879 and 1912. Since the 1960s, the government has implemented economic development programs, territorial occupation and construction of highways, such as BR-230, also known as Transamazônica. This highway had a significant impact on the southwest region of Pará, especially in the Xingu River basins, contributing to disorderly deforestation and harming biodiversity, especially on the banks of water bodies. To deal with environmental problems, several analysis and monitoring methods have been developed, including remote sensing, which allows large areas to be studied in a short time. Biological monitoring is also used, as some organisms, such as aquatic insects from the infraorder Gerromorpha, are sensitive to environmental changes and can indicate the quality of the habitat. Therefore, a recent study analyzed the history of land use in the region over the last 30 years and evaluated the composition of the Gerromorpha infraorder in Transxingu streams. A large loss of vegetation cover has been observed in recent decades, especially close to roads, often related to livestock farming. However, there has been a reduction in deforestation over time, possibly due to conservation measures, such as the Action Plan for the Prevention and Control of Deforestation in the Legal Amazon (PPCDAm), creation of extractive reserves, recognition of indigenous lands and the Cadastre Rural Environmental (CAR). In the study of the composition of the Gerromorpha infraorder in the Transxingu streams, it was found that many samples were influenced by deforestation over the years. Furthermore, it was found that the integrity index of the stream's physical habitat can be more effective than geospatial metrics in assessing environmental impact. Although there were no significant differences in the Gerromorpha community between preserved and altered environments, a variation in the abundance of these organisms was noticed along environmental gradients. This indicates that the community responds to changes in the environment, regardless of the presence of specific bioindicator species. Therefore, there is a need for more studies in highly preserved environments to better understand these dynamics.
Acesso aberto (Open Access)
Histórico do uso da terra e composição de gerromorpha (insecta: subordem heteroptera) em igarapés da Transxingu
(Universidade Federal do Pará, 2024-02-28) COSTA, Iluany da Silva; SILVA, Karina Dias da; http://lattes.cnpq.br/2271768102150398; https://orcid.org/0000-0001-5548-4995
The Amazon Forest faces threats due to the increasing exploitation of natural resources driven by the economic growth of the region, intensified since the exploitation of rubber between 1879 and 1912. Since the 1960s, the government has implemented economic development programs, territorial occupation and construction of highways, such as BR230, also known as Transamazônica. This highway had a significant impact on the southwest region of Pará, especially in the Xingu River basins, contributing to disorderly deforestation and harming biodiversity, especially on the banks of water bodies. To deal with environmental problems, several analysis and monitoring methods have been developed, including remote sensing, which allows large areas to be studied in a short time. Biological monitoring is also used, as some organisms, such as aquatic insects from the infraorder Gerromorpha, are sensitive to environmental changes and can indicate the quality of the habitat. Therefore, a recent study analyzed the history of land use in the region over the last 30 years and evaluated the composition of the Gerromorpha infraorder in Transxingu streams. A large loss of vegetation cover has been observed in recent decades, especially close to roads, often related to livestock farming. However, there has been a reduction in deforestation over time, possibly due to conservation measures, such as the Action Plan for the Prevention and Control of Deforestation in the Legal Amazon (PPCDAm), creation of extractive reserves, recognition of indigenous lands and the Cadastre Rural Environmental (CAR). In the study of the composition of the Gerromorpha infraorder in the Transxingu streams, it was found that many samples were influenced by deforestation over the years. Furthermore, it was found that the integrity index of the stream's physical habitat can be more effective than geospatial metrics in assessing environmental impact. Although there were no significant differences in the Gerromorpha community between preserved and altered environments, a variation in the abundance of these organisms was noticed along environmental gradients. This indicates that the community responds to changes in the environment, regardless of the presence of specific bioindicator species. Therefore, there is a need for more studies in highly preserved environments to better understand these dynamics.
Acesso aberto (Open Access)
Prototipagem de sistema de alarme de incêndio baseado em sensor nanoestruturado integrado a IoT
(Universidade Federal do Pará, 2021-06-29) FREITAS, Luís Gustavo Oliveira de; REIS, Marcos Allan Leite dos; http://lattes.cnpq.br/8252507933374637
The improvement of remote sensing systems for the detection of forest fires or industrial plants is fundamental to the development of industry 4.0, and it is becoming increasingly important for many countries where forest fires occur frequently. Therefore, it is necessary to design and explore a device that has a quick response, that has remote monitoring in real time and can generate warning signs that precede major fires in indoor (indoor) and outdoor (outdoor) environments, this nanostructured sensor based on buckypaper that it consists of carbon nanotube films and has thermal sensitivities that can be measured in short response times. In the prototyping of the fire alert sensor, thermal tests were carried out to evaluate the effectiveness. Furthermore, it was integrated with IoT (Internet of Things) using the NodeMCU architecture together with the MQTT (Message Queuing Telemetry Transport) protocol, thus enabling the sending of the alert message to the end user through an Android application. Preliminary results show that this nanostructured sensor can be effective at distances of less than 1 meter from the fire source, for example at 20 cm, generating a thermovoltage of 2.3 mV over 80 seconds with a heat source at 240 ° C. This work shows the entire development process of this prototype with real-time monitoring with the function of issuing an early fire alert.
Acesso aberto (Open Access)
O sistema eólico das bacias costeiras de São Luís e Barreirinhas, NE do Brasil: implicações climáticas e tectônicas durante o Quaternário
(Universidade Federal do Pará, 2021-10-25) SILVA JUNIOR, Antônio Gonçalves da; SUNDAL, Anja; NOGUEIRA, Afonso César Rodrigues; http://lattes.cnpq.br/8867836268820998
Active and stabilized dune fields, built by NE trade winds in a wave- and tide-dominated coastal system characterizes the region between São Marcos Bay, Maranhão State, and the Parnaíba River Delta, Piauí State, northeastern coast of Brazil. In this context, Lençóis Maranhenses is the largest active dune field in South America with approximately 1,026 km2, adjacent to the largest stabilized eolian deposits with about 19,000 km2 covering basement rocks. These deposits mainly fill the onshore portion of the Barreirinhas Basin, and the NE-SW Pirapemas Lineament represents the main structure of the basement. Previous gravimetry and seismic data show that the NW portion of this lineament is a subsided block that controls the Holocene deposition. The main factors for the origin and preservation of this sedimentation were variations in humidity, wind speed, vegetation cover, and relative sea-level changes since the Pleistocene. Furthermore, the neotectonics events are confirmed and linked to the Pirapemas Lineament reactivation. The mapping of active and inactive morphologies of this eolian system, based mainly on remote sensing products, previous geochronological and field data, allowed us to infer evolutionary stages that culminated in the current relief configuration of the region. The interpretation of medium to high spatial resolution optical satellite images (SENTINEL-2 and CBERS-4a) and digital elevation model (ALOS) were suitable for the compilation of age data (LOE, C14, and thermoluminescence) to provide a spatial- that supported the proposed geological evolution. The eolian deposits are typical of the transgressive dune field, comprising about 20,000 km2, of active (12 %) and inactive (88 %) morphologies. The active deposits are close to the coast and consist of barchans, barchanoid and transverse ridges. Inactive deposits migrate inland for up to 150 km and are formed by parabolic dune morphologies, stabilized transverse ridges, and deflation plains. Although the older ages are unrepresentative, it suggests that these dune fields may have started 240,000 BP. The published age concentrations of the Late Pleistocene punctuate successive pulses of migration and preservation influenced by relative sea-level changes triggered from Quaternary glacial and interglacial cycles. Under more arid conditions, the coastal-eolian system had its most landward remarkable expansion during the Last Glacial Maximum (~22,000 BP). At the same time, the most significant preservation occurred between 19,000 and 14,000 BP, under a humid climate reflecting the Henrich event (HS1). In the Holocene, the normal reactivation to the NW of the Pirapemas Lineament increased the accommodation space with extensive development of coastal systems. The SE region from this lineament was uplifted, causing progressive dune field abandonment and reworked by deflation. These two distinct compartments form the current configuration of the coastal wind deposits in the onshore Barreirinhas Basin.
Acesso aberto (Open Access)
O uso de Veículos Aéreos Não Tripulados (VANTs) para inspenções de segurança em barragens: estudo exploratório UHE Tucuruí
(Universidade Federal do Pará, 2021-05-28) EL BANNA, Kamila Dias Bernardes; TEIXEIRA, Marcelo Rassy; http://lattes.cnpq.br/8912916360456192
The main objective of this research is to verify the applicability of remote sensing by Unmanned Aerial Vehicles (UAVs), or popularly known as (drones) to aid in the safety of security in hydroelectric dams. It highlights the role and importance of technology as a means of innovation, for this application, as an exploratory study of the UHE Tucuruí. Some signs of deterioration or cracking, for example, can only be identified with visual inspections. For this reason, they are irreplaceable in dam safety control. In this context, the use of the UAV is very useful in these inspections, since its use makes this activity faster and safer, as it allows the verification of regions of the dam that are difficult to access, thus enabling full documentation of the dam's conservation status, in addition to the possibility of adapting sensors of different types and applicability, thus helping to provide more detailed information. The UAV, used for this research, satisfactory results for the evaluations to which it was exposed. Images with adequate quality and sequences were generated, so you can easily observe all the characteristics of the dam surface, thus providing a good support in the operation activities. In addition to supporting the dam safety assessment, the images generated can be gathered and used as a basis for other photographic surveys.