46 research outputs found

    Estudo preliminar sobre a viabilidade de detecção de macrófitas flutuantes através de processamento digital de dados do MSS/Landsat

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    Descreve-se a avaliacao da viabilidade de mapear, atraves de processamento digital de dados do MSS/LANDSAT, as areas ocupadas por macrofitas flutuantes (predominantemente aguape: Eichornia crassipes)na represa de Salto Grande em Americana, SP. A area ocupada pelas macrofitas foi extraida por exclusao apos a superposicao de duas mascaras tematicas que representam a area da lamina d'agua sem cobertura vegetal. Uma das mascaras foi obtida de uma data em que a cobertura de macrofitas e insignificante e a outra, de um episodio de grande infestacao. Conclui-se que a utilizacao de tecnicas de processamento digital de dados do MSS/LANDSAT, para documentar infestacoes de macrofitas, so e viavel quando o fenomeno ocupa grandes extensoes

    Abordagem analítica e sequencial para a classificação de ortofotos para o mapeamento de mosaico de Floresta e Campo no Parque Estadual de Campos do Jordão

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    Maps of the Araucaria Forest and Grassland mosaics, a typical landscape of Ombrophilous Mixed Forests in Brazilian south and southeastern regions are fundamental to understand its spatial and temporal dynamics. This work describes a reproducible analytical method for imaging processing and classification for the production of land cover map in such landscape for comparisons among different sites and dates. The work was conducted in Campos do Jordão State Park, São Paulo State, Brazil, which was created in 1941 to protect remnants of Araucaria Forest in the southeastern region of the country. The classification method comprises of nested region based classifications of orthorectified digital aerial photographs applied sequentially on band ratio and simple spectral bands. Classes that presented ambiguities in the classification of the band ratio were refined with further classifications of simple spectral band. The results showed that the methodology generated a good representation of the vegetation cover in a representative sample of the Campos do Jordão State Park landscape. The comparison of the Land Cover Map produced in this work with a previous one produced in 1975 showed consistence in the representation of landscape features that demonstrated stability in vegetation cover which emphasizes the role of this conservation unit for Araucaria Forest preservation. Evidences of forest encroachment over grassland were identified as well as forest degradation.Pages: 2905-291

    Transgressão do Código Florestal no Município de Piquete – SP

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    A Mata Atlântica possui uma taxa anual de desmatamento de 5,76, acarretando inúmeras conseqüências como prejuízos sociais e problemas ambientais. Entretanto, o país possui uma legislação específica para a proteção da cobertura vegetal, o Código Florestal Brasileiro, cujo objetivo é o de prevenir e corrigir danos causados pelo desmatamento. Esta legislação determina a preservação permanente de áreas específicas, levando em conta a participação da cobertura vegetal na proteção do solo e de recursos hídricos. O objetivo deste trabalho é demonstrar a aplicabilidade de métodos de Sensoriamento Remoto e Geoprocessamento para detecção de transgressão do Código Florestal. Demostra-se para o município de Piquete, SP, que é possível o mapeamento de áreas de preservação permanente conforme critérios do Código Florestal e a detecção de áreas com cobertura vegetal em desacordo com a referida legislação ABSTRACT: The Atlantic Forest has an annual deforestation rate of 5.76 which leads to many environmental end social deleterious consequences. The country has a specific legislation for the protection of the vegetation cover, the Brazilian Forest Protection Act, which has the objective of control and mitigate damages caused by deforestation. The Act establishes the permanent preservation of specific areas taking into account the role of the vegetation cover in the protection of soils and water resources. The objective of this work is to demonstrate the applicability of Remote Sensing and Geoprocessing techniques for the detection of transgressions of the Forest Protection Act. It is demonstrated for the municipality of Piquete, São Paulo State, that it is possible to map the permanent protection areas as stated in the Act and to detect areas where the vegetation cover is in disagreement with the referred legislation.Pages: 611-61

    Fitossociologia e condições ambientais na Mata Atlântica: proposta de elaboração de um banco de dados geográficos

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    O entendimento de padrões de distribuição espacial das espécies é fundamental para a conservação da diversidade biológica. Técnicas de Geoprocessamento e de Sensoriamento Remoto podem ser aplicadas na busca deste entendimento pois permitem a integração e análise de dados de diversas fontes e com diversos formatos. Dados tabulares como inventários fitossociológicos podem ser integrados e analisados em conjunto com dados geográficos descritos por campos discretos ou grades em diversas resoluções espaciais. O objetivo deste trabalho é elaborar um banco de dados geográfico contendo informações florísticas publicadas em levantamento fitossociológicos realizados na Mata Atlântica e informações ambientais disponíveis como normais climáticas, mapas pedológicos e grades topográficas. O banco de dados será utilizado análises de classificação e ordenação de comunidades vegetais na Mata Atlântica, considerando o contexto espacial e ambiental da informação florística. Espera-se desta análise, a determinação de áreas de maior diversidade, áreas com falta de informação florística, bem como a análise de correlações entre a distribuição de certas espécies florestais e condicionantes ambientais. ABSTRACT: The understanding of the spatial pattern of species distribution is a basic requirement for the conservation of biological diversity. Remote Sensing and Geoprocessing techniques can be applied in the search of such understating for they allow the integration and analysis of data from different sources and presented in different formats. Tabular data such as fitossociological inventories can be integrated and analyzed together with geographical data presented as discrete fields or regular grids of different spatial resolution. The objective of this work is to construct a geographical data base with floristic information from published fitossociological inventories of the Atlantic Forest and available environmental information such as climatic and soil maps and topographic grid. The data base will be used in the classification and ordination analysis of plant communities in the Atlantic Forest, considering the spatial and environmental context of the floristic information. It is expected from this analysis the determination of high diversity sites, the determination of areas where floristic information is scarce as well as the evaluation of the correlation between the spatial distribution of certain plant species and the environmental constraints.Pages: 409-41

    Estudo preliminar sobre a aplicação de processamento digital de dados TM-Landsat no mapeamento de pomares de maçã em Fraiburgo, SC

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    Atraves da analise de dados TM-LANDSAT procurou-se avaliar a discriminabilidade de areas maleicolas de outros usos da terra na regiao de Fraiburgo-SC. A verdade terrestre foi um aerolevantamento pancromatico de setembro de 1979 (1:20.000)e verificacao de campo em janeiro de 1986 e analisou-se os dados TM-LANDSAT (221/79-A, dezembro de 1984, bandas TM: 2, 3, 4 e 7)no sistema IMAGE-100 (1:25.000). A area de estudo foi aplicada uma classificacao digital hibrica. A aplicacao do algoritmo K-MEDIAS (nao supervisionado)obteve 8 classes espectrais. Estas foram divididas em 18 classes supervisionadas pelo algoritmo MAXVER abrangendo 8 classes informativas: PINUS, MATA, MACA, SOLO PREPARADO, PASTAGEM, AGUA, AREAS ALAGADAS E AREA URBANA. A analise da localizacao destas classes no espaco de atributos TM-3 x TM-4 indicou que as 3 classes supervisionadas de MACA apresentaram superposicoes com classes de MATA, PASTAGEM E AREAS ALAGADAS. Atribui-se estas confusoes as diferencas de conducao e de idade dos pomares (de 5 a 20 anos). Sugere-se uma abordagem multitemporal, explorando as caracteristicas fenologicas de MACA, para melhor descrimina-la dos demais usos da terra.Pages: 21

    Adjustments to SIF Aid the Interpretation of Drought Responses at the Caatinga of Northeast Brazil

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    Sun-Induced chlorophyll Fluorescence (SIF) relates directly to photosynthesis yield and stress but there are still uncertainties in its interpretation. Most of these uncertainties concern the influences of the emitting vegetation’s structure (e.g., leaf angles, leaf clumping) and biochemistry (e.g., chlorophyll content, other pigments) on the radiative transfer of fluorescent photons. The Caatinga is a large region in northeast Brazil of semiarid climate and heterogeneous vegetation, where such biochemical and structural characteristics can vary greatly even within a single hectare. With this study we aimed to characterize eleven years of SIF seasonal variation from Caatinga vegetation (2007 to 2017) and to study its responses to a major drought in 2012. Orbital SIF data from the instrument GOME-2 was used along with MODIS MAIAC EVI and NDVI. Environmental data included precipitation rate (TRMM), surface temperature (MODIS) and soil moisture (ESA CCI). To support the interpretation of SIF responses we used red and far-red SIF adjusted by the Sun’s zenith angle (SIF-SZA) and by daily Photosynthetically Active Radiation (dSIF). Furthermore, we also adjusted SIF through two contrasting formulations using NDVI data as proxy for structure and biochemistry, based on previous leaf-level and landscape level studies: SIF-Yield and SIF-Prod. Data was tested with time-series decomposition, rank correlation, spatial correlation and Linear Mixed Models (LMM). Results show that GOME-2 SIF and adjusted SIF formulations responded consistently to the observed environmental variation and showed a marked decrease in SIF emissions in response to a 2012 drought that was generally larger than the corresponding NDVI and EVI decreases. Drought sensitivity of SIF, as inferred from LMM slopes, was correlated to land cover at different regions of the Caatinga. This is the first study to show correlation between landscape-level SIF and an emergent property of ecosystems (i.e., resilience), showcasing the value of remotely sensed fluorescence for ecological studies
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