Resumo -O objetivo deste trabalho foi avaliar a adequação do uso do sensor AVHRR/NOAA (Advanced Very High Resolution Radiometer/National Oceanic and Atmospheric Administration) para mapeamento da temperatura da superfície terrestre (TST) Termos para indexação: sensoriamento remoto, janela dividida, temperatura do ar, infravermelho, termal. were compared for the minimum LST estimation, using nocturnal and predawn images. Both emissivity and LST data were obtained by means of mathematical combinations of the visible, near-infrared and thermal detected radiation of the AVHRR/NOAA sensor. The AVHRR sensor is suitable for LST mapping for the overall conditions of soil coverage in Rio Grande do Sul, once the estimated LST, by the three tested methods, was close to the measured air temperature at the selected locations. Sobrino et al. was the most adequate method. Mapping land surface temperature using AVHRR/NOAA sensor
Turbid coastal plumes carry sediments, nutrients, and pollutants. Satellite remote sensing is an effective tool for studying water quality parameters in these turbid plumes while covering a wide range of hydrological and meteorological conditions. However, determining boundaries of turbid coastal plumes poses a challenge. Traditionally, thresholds are the approach of choice for plume detection as they are simple to implement and offer fast processing (especially important for large datasets). However, thresholds are site-specific and need to be re-adjusted for different datasets or when meteorological and hydrodynamical conditions differ. This study compares state-of-the-art threshold approaches with a novel algorithm (PLUMES) for detecting turbid coastal plumes from satellite remote sensing, tested for Patos Lagoon, Brazil. PLUMES is a semi-supervised, and spatially explicit algorithm, and does not assume a unique plume boundary. Results show that the thresholds and PLUMES approach each provide advantages and limitations. Compared with thresholds, the PLUMES algorithm can differentiate both low or high turbidity plumes from the ambient background waters and limits detection of coastal resuspension while automatically retrieving metrics of detected plumes (e.g., area, mean intensity, core location). The study highlights the potential of the PLUMES algorithm for detecting turbid coastal plumes from satellite remote sensing products, which can have significantly positive implications for coastal management. However, PLUMES, despite its demonstrated effectiveness in this study, has not yet been applied to other study sites.
Management of estuarine systems under anthropogenic pressures related to port settlement and development requires thorough understanding about the long-term sediment dynamics in the area. In an era of growing shipping traffic and of ever larger ships; millions of tons of bottom sediments are dredged annually all over the world and the major question concerning dredging operations is not whether they should be done, because it is obvious that they are extremely important and necessary, but where the dredged sediments can be disposed of with the least possible ecological impact. The present study involves the evaluation of transport trends of dredged material from a turbid estuary disposed of in four different open ocean disposal sites using numerical model techniques, aiming to contribute to minimizing potential environmental impacts and maximizing efficiency of the dredging operation. The study is carried out in southern Brazil, investigating the fate of dredged material from the Port of Rio Grande, located inside the Patos Lagoon estuary. Simulations were carried with the TELEMAC-3D model coupled with the suspended sediment (SEDI-3D) module and incorporating results from the wave module (TOMAWAC) to evaluate the dispersion of the suspended sediment plume and its interaction with coastal currents. This modeling structure proved to be a valuable tool to study the hydrodynamics and sediment transport pathways in estuarine and coastal areas. Results indicate that the natural Patos Lagoon coastal plume was observed under the predominant ebb flows and NE winds, promoting fine sediment entrapment south of the mouth of the lagoon (in front of Cassino Beach). The dispersion plumes in the disposal sites responded to the wind intensity and direction and did not present any transport tendency towards Cassino Beach. Part of the dredged sediment disposed of in the proposed alternative sites located in deeper areas (Sites B and C) left the site and was transported parallel to the coast (SW–NE direction) according to the wind direction (NE–SW). The area where the disposal sites were located took around 4 days to recover from the dredging operation and reach the usual suspended sediment concentrations and the actual Port of Rio Grande Licensed Site for dredged material proved to be the best alternative among the investigated options
Resumo:A automação do processo de revisão e atualização da cartografia de áreas urbanas ainda constitui um desafio aos desenvolvedores de sistemas computacionais de alta produtividade. Uma das questões que permeia esse processo é a quantificação da similaridade entre objetos representados no espaço vetorial (bases cartográficas digitais) e segmentados no espaço matricial (imagens de alta resolução). A pesquisa desenvolvida no Laboratório de Fotogrametria do Departamento de Geomática da UFPR, ora apresentada, parte da premissa da existência de dados qualificados que permitam a segmentação precisa da imagem, a associação dos segmentos gerados às edificações erigidas sobre o terreno e a adequada georreferência dos dois conjuntos de informações. A partir desse resultado, o método proposto explora uma métrica topológica robusta, a Distância de Hausdorff, para determinação da condição de atualidade da representação cartográfica em função dos elementos presentes na imagem. Os testes de desempenho dessa métrica para uma área urbana com dados disponíveis demonstram uma alta taxa de concordância quando comparados os resultados com a fotointerpretação profissional e demonstrou-se que a medida é robusta à parcial obstrução dos objetos em comparação. Palavras-chave: Distância de Hausdorff, Processamento de Imagens, Medida de Similaridade, Automação Cartográfica Abstract:The automatic process of reviewing and updating urban maps is still a challenge to developers of high productivity computer systems. One of the intrinsic issues of this process is to quantify the similarity between objects represented in the vector space (digital cartographic bases) and that
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