Sentinel-2A Images and Spectroradiometry Applied to Degraded Grassland Study

The goal of this study is distinguish on remote sensing data, different conservation stage from pasture areas, using laboratorial analysis, orbital images and field spectroscopy, comparing field and laboratory methods. Was studied two pasture areas with grass Brachiaria decumbens, the area 1 without degradation and the area 2 degraded. The orbital sensor changed chosen was Sentinel-2 MSI, and yours images was used on Leaf Area Index (LAI) estimative and in obtaining the reflectance of the canopies, as well as using a field spectrometer. The concentration of chlorophyll was quantified, where the degraded area presented lower values, denoting low force. The LAI computation was efficient in the separation of the degraded area, which presented lower LAI, however the satellite reflectance data did not result as expected, because the degraded area reflected less energy in the red, however the recognition of coverage patterns was observed mainly in area without degradation. The chlorophyll content in the canopies was compared with reflectance obtained with the field spectrometer, and in the reflectance graphics presented particular features. However, the reflectance spectra were better analyzed after applying the information extraction techniques, in which the spectral derivative and the removal of the continuum were efficient to differentiate the areas, confronting with the chemical dat

Determinação de metais pesados (Mn, Cd, Cr, Cu, Pb) em peixes das espécies Astyanax bimaculatus, Hoplias malabarcius e Oreochromis niloticus presente na Lagoa Salgada – Rio Subaé - Feira de Santana (Bahia)

O Brasil tem um dos maiores complexos hidrográficos do mundo. Devido ao abrupto crescimento urbano e industrial das últimas décadas, a qualidade da água dos corpos aquáticos brasileiros tem sido alterada. As nascentes do rio Subaé, representadas nesse trabalho pela lagoa Salgada, estão localizadas na cidade de Feira de Santana-BA, tem apresentado visíveis alterações na qualidade da água. Neste trabalho foram utilizadas algumas espécies de peixes para fazer o monitoramento da área estudada: espécie Astianax bimaculatus (lambari), Hoplias malabarcius (traíra), Oreochromis niloticus (tilápia). Este trabalho objetivou determinar o grau de comprometimento, em relação à contaminação por metais pesados, nas espécies de peixes presentes na lagoa Salgada, da Bacia do Subaé-BA. As análises feitas do tecido muscular não detectaram Cr e Cd em nenhuma das espécies. O elemento Cu foi detectado em A. bimaculatus, H. malabarcius, e O.niloticus,com médias de 1.59, 1.89 e 0.05 respectivamente. O Pb foi encontrado, em todas as espécies analisadas, concentrações acima do valor máximo para consumo humano (13,8 em A. bimaculatus, 8,32 H. malabarcius e 15,9 em O. niloticus), o que oferece risco tanto aos organismos envolvidos na cadeia alimentar do ambiente como a população que reside e consume os peixes desta lagoa

Modelagem da Qualidade da Água na Bacia Hidrográfica do Rio Coisa Boa - Igatu - Chapada Diamantina - Bahia

This research aims at modeling the Good thing Basin (BCB), region Igatu, Chapada Diamantina - Bahia, especially as the physico-chemical quality of surface waters. The study area lies within the limits of the National Park of Chapada Diamantina (PNCD) and listed as a Historic, belonging to the municipality of Andaraí. Regarding the methodological procedures was used: principal components analysis (PCA), application of IQABa, spatial analysis methods by the inverse square of the distance and line graphs. The months were as follows: April, July and October 2010 and January 2011, covering twenty (20) sampling sites upstream and downstream of the BCB. The physicochemical parameters used to implement IQABa are those representing the Principal Component Analysis (PCA), which further explain how the quality of the waters of BCB: turbidity, total solids, pH, phosphate, nitrate, BOD and conductivity. From the results obtained during the sampling campaign, did the calculations Index Water Quality of Bascarán (IQABa) (Bascarán, 1979 apud Rizzi, 2001). The analysis of water quality of the BCB was performed in twenty collection points, contemplating headwater areas with little human interference, primary contact recreation, sewage discharge and areas around the mouth. It is observed that the quality of water in BCB decreases from upstream to downstream, as it is the entry of effluent generated by the anthropogenic Village Igatu. The amount of the BCB, has an area with springs, with little human interference and with good water quality, even in the dry season, reflecting the natural water of the study area. As for surface maps for the area studied, the technique called inverse square of the distance was visually satisfactory to the spatial data.Pages: 6526-653

ANÁLISE DE METAIS-TRAÇOS EM SEDIMENTOS DA APA DO PRATIGI, BAHIA

Na APA do Pratigi, Sul da Bahia, pontua-se como uso do solo, atividades agrícolas, pequenas hidrelétricas e piscicultura. Este trabalho analisou as concentrações de Cu, Pb, Cr, Zn e Ni nos sedimentos da Bacia do Rio Juliana. Revelou-se que existe uma grande variação entre as concentrações de metais-traços encontradas ao longo da bacia analisada e que esta variação pode ser explicada pelo uso do solo ao entorno dos pontos de amostragem, além da geomorfologia da região. Porém, apenas as concentrações de Cr apontaram uma possível contaminação do sedimento, que pode ser proveniente do uso de defensivos agrícolas, à base de Cr, em grande escala. Assim, os gestores da APA podem propor medidas mitigadoras para áreas com concentrações significativas de Cr, e no ambiente, livres de atividade antrópicas, que apresentou melhor qualidade ambiental, em relação às concentrações de metais-traços, pode ser útil como um ambiente referencial para sedimentos da Mata Atlântica

Comportamento espectral do solo da Caatinga em diferentes tipos de manejos

The premise that guides this work is to discriminate, from reflectance measurements obtained in the laboratory, the chemical attributes of the same type of soil in three experimental areas of the Embrapa at systems of distinct management and land use. The systems of use and management of the soils are: organic mango crop, Caatinga degraded and Caatinga preserved. Thus, it is expected that the soil characteristics can be estimated by differences at reflected energy. From the spectral analysis was possible to identify the attributes existing in the samples because the absorption bands which varied in breadth and depth, but not in placement.In part, this can be attributed to organic matter that directly affects the biological characteristics of the soil acting as a carbon source, energy and nutrients for microorganisms and is significantly correlated with the intensity of reflectance across the spectrum. Thus, from the spectra, it was found that the content of organic matter is higher in the savanna preserved because it has a lower reflectance, while the cultivation of organic mango has a higher reflectance consequently a lower content of organic matter. This research aims to assist the technical progress of agriculture as the basis for planning without affecting the environmental aspects.Pages: 9080-908

Influência entre os constituintes químicos e físicos do solo na sua resposta espectral

This study aims to analyze the influence of chemical and physical constituents of the soil in their spectral response, since the interaction of electromagnetic energy with the soil can be changed depending on the variability of their attributes. The research was conducted in reference-areas of preserved Caatinga, degraded Caatinga, buffel grass (Cenchrus ciliaris L.) and Mango crop (Mangifera indica L.), located at Embrapa Semiarid in Petrolina - PE. We used georeferenced data of 120 soil samples. The chemical and physical analyzes were performed at the Soil Laboratory of Embrapa Semi-Arid and the spectral measurements in the Spectroradiometry Laboratory of UEFS. The spectral curves obtained by spectroradiometry demonstrated how soil attributes act upon their spectral response. From the spectral curves were defined absorption bands throughout the spectrum that correlated significantly with soil attributes. By correlating the chemical and textural analyzes with the spectral curves we can see how each attribute influences the soil reflectance and thus predict the range that each attribute can be better interpreted. In addition, the correlation can demonstrate which of attributes are most influential or significant for the formation of absorption features. For the analyzed soil the best responses were found for the micronutrients Fe, Cu and Zn.Pages: 9195-920