Josiclêda Domiciano Galvíncio

Análise quantitativa de parâmetros biofísicos de bacia hidrográfica obtidos por sensoriamento remoto

The objective of this work was to quantitatively evaluate the biophysical parameters, obtained by remote sensing, for the range area of the Tapacura River Basin, in Pernambuco state, Brazil. Landsat 5‑TM images of 7/10/1989, 7/6/2005, and 8/29/2007 were used. The images were registered with a polynomial geometric correction of first order. Radiometric calibration, reflectance, transmittance and planetary albedo were calculated and, subsequently, thematic maps of surface albedo, surface temperature and enhanced vegetation index (EVI) were generated. The surface albedo showed increasing average values between the 1989 and 2005 images, which indicates the urban territorial expansion. The image of 8/29/2007 showed the highest land surface temperature, followed by the temperatures showed in the images of 7/10/1989 and 7/6/2005, and the highest values were those of the urban networks. The 1989 image showed the highest average value for EVI, which indicates that there was a higher vegetation presence in that date.

Evapotranspiração e estimativa da água consumida em perímetro irrigado do Semiárido brasileiro por sensoriamento remoto

The objective of this work was to map the actual evapotranspiration (ETr) and to determine the volume of water used in the irrigation project of Sao Goncalo, PB, in the Brazilian Semiarid Region, using remote sensing. TM/Landsat 5 images were acquired from the study area, in 2008, and were used to obtain thematic maps of daily ETr. Two dwarf coconut crops were selected for validation of the results of evapotranspiration obtained by the surface energy balance algorithm for land (ETSebal) and the FAO‑56 method (ETFAO). In order to determine ETFAO, the product between the culture coefficient, the adjustment coefficient, and the reference evapotranspiration was used. The differences obtained by the two techniques resulted in root mean square error, mean relative error, and mean absolute error equal to 0.53 mm, 9.46%, and 0.43 mm, respectively. In the irrigated areas, ETr represented about 85% of net radiation and, in rainfed plots, only 12.5%. The mapping of ETr clearly delimitated the irrigated and nonirrigated plots, as well as the differences within the irrigated perimeter of the project under investigation. The volume of water applied in the irrigation project, only in the period from July to December, represents more than 60% of the capacity of the Sao Goncalo reservoir.

Determinação do saldo radiativo na Ilha do Bananal, TO, com imagens orbitais

Remote sensing may be used to identify changes that occur in land use of Earth, resulting from natural and/or anthropic processes. Many of these changes can be diagnosed from the monitoring of radiative exchanges that take place at the surface. In this sense, this study aims to determine the net radiation at surface, by means of sateLλite images covering Bananal Island, in the State of Tocantins, Brazil. TM-Landsat 5 images obtained in 2005 (cloud free), were used to generate maps of instantaneous and daily net radiation (Rn) based on SEBAL. The Rn values were validated with measurements performed in a micrometeorological tower installed within the Bananal Island. The instantaneous Rn values varied between 488.0 and 535.0 W m-2; while the daily Rn values varied between 132.7 and 145.3 W m-2. The disturbed areas showed decrease in net radiation. The daily net radiation presented relative mean error, mean absolute error and square root of mean square error equal to 1.95%, 2.78 W m-2 and 3.36 W m-2; respectively. According to the results, it may be concluded that the methodology used for Rn determination presented good accuracy.

Estimativa do balanço de energia utilizando imagens TM - Landsat 5 e o algoritmo SEBAL no litoral sul de Pernambuco

The energy exchange across soil vegetation-atmosphere interface through the net radiation components (Rn) the soil heat flux (G), sensible heat flux (H) and latent heat flux (LE) are of vital importance for the climatic and hydrologic modeling, which affects all biosphere. The main objectives of this research are: (1) to estimate and compare the several energy balance components behavior, using SEBAL algorithm, under different soil usages; and (2) to validate SEBAL algorithm. In order to make the analysis, three TM - Landsat 5 images, from orbit and point 214/066, of August 26th 2006, September 6th 2010 and January 28th 2011, covering the South Coast of Pernambuco State (Brazil) were used. The results showed the ability of SEBAL to estimate the spatial variability of the different components of energy balance, with the ability to distinguish different soil occupations. The calculation of the energy balance components allows to figure the different forms of energy usages by different soil coverage and to find those that provide better thermal comfort. Estimates of evapotranspiration obtained by the algorithm SEBAL showed a good agreement with the results obtained by the FAO-Penman-Monteith, thus demonstrating the potential of this methodological approach.

Determinação por sensoriamento remoto da produtividade primária bruta do perímetro irrigado São Gonçalo - PB

ABSTRACT: ASSESSMENT OF GROSS PRIMARY PRODUCTION - GPP IN THE IRRIGATED PERIMETER SAO GONCALO - PB USING REMOTE SENSINGThe Gross Primary Production (GPP) assessment and monitoring by remote sensing is of crucial importance in the climate changes studies given its direct connection to the effectively extracted carbon from the atmosphere by numerous earth ecosystems. The present work aims to assess the GPP in a Brazilian semi-arid irrigated area, using TM – Landsat 5 images and complementary surface meteorological data. Cloudless TM images were acquired from the year 2008 and were used to obtain daily GPP for five selected days. This model expresses GPP as a function of the absorbed photosynthetic active radiation and the efficiency of light use by vegetation. A comparison is made between the obtained results with TM images and GPP from MOD17A2. The difference between GPP values obtained by the two techniques resulted in an Average Absolute Difference - AAD of 0.91 g C m -2 dia -1 , an Average Percentage Difference - APD of 11.82% and Root Square Mean Difference - RSMD of 1.12 g C m

Índice de umidade (NDWI) e análise espaço-temporal do albedo da superfície da bacia hidrográfica do rio Moxotó-PE

O sensoriamento remoto permite o monitoramento espaco-temporal dos recursos naturais em diversas partes do mundo de maneira eficiente e sistematica, vindo a apresentar grande auxilio nas areas de agricultura, silvicultura, bem como em previsoes meteorologicas e hidrologicas. Deste modo, diversos indices tem se apresentado mais recorrentemente na literatura, como os indices de vegetacao e do albedo superficial. Considerando as grandes mudancas espaco-temporais ocorridas em bacias hidrograficas e a influencia destas mudancas no ciclo hidrologico das mesmas, este estudo objetiva avaliar mudancas ocorridas espaco-temporalmente na bacia hidrografica do rio Moxoto-PE, aplicando o NDWI e albedo da superficie, obtidos com imagens orbitais. Foram utilizadas imagens dos satelites Landsat 5 e 7, orbita-ponto 215-66 datadas em 09 de maio de 1987, 20 de abril de 1992, 15 de maio de 2001, 11 de abril de 2003 (ETM+), 02 de maio de 2008 e 24 de maio de 2010, alem de dados de radar SRTM, dados meteorologicos e mapa de uso e cobertura do solo da referida bacia. O Indice de Umidade (NDWI) complementou as cartas de albedo da superficie na analise multitemporal das mudancas de uso e cobertura do solo, auxiliando os planejadores publicos no gerenciamento do uso e cobertura do solo de bacias hidrograficas. A grande variabilidade na quantidade e periodicidade da precipitacao indica que o Indice de Umidade e o albedo da superficie detectam grandes mudancas na resposta espectral dos alvos em estudo. A elaboracao de perfis do albedo da superficie e do Indice de Umidade auxiliou na avaliacao e entendimento do comportamento dos alvos na bacia hidrografica do rio Moxoto, tornando possivel observar grande destaque para as areas com corpos hidricos, agricultura irrigada e vegetacao de porte arboreo fechado, e valores de umidade mais elevados.

CARACTERIZAÇÃO AMBIENTAL DA BACIA HIDROGRÁFICA DO RIO MOXOTÓ – PE USANDO SENSORIAMENTO REMOTO TERMAL

Os produtos do Sensoriamento Remoto orbital vem se tornando uma importante ferramenta para as mais variadas aplicacoes, particularmente aquelas relacionadas com a avaliacao, manejo, gerenciamento e gestao de recursos naturais, como agua, solo e vegetacao. Este estudo visa realizar uma caracterizacao ambiental da Bacia Hidrografica do Rio Moxoto, atraves do balanco de radiacao. Para isto foram utilizadas duas imagens do mapeador tematico do satelite Landsat 5 de orbita e ponto 215/66 com passagem em 27-09-1992 e 12-10-2003, que foram processadas, organizadas e analizadas em ambiente GIS. A diminuicao da cobertura vegetal e evidente na analise temporal e espacial das duas datas analisadas. Esta diminuicao fez com que em algumas areas da bacia ocorresse um aumento de temperatura. As areas de cimeira, com altitudes superiores a 600m apresentaram indices de SAVI com valores superiores a 0.211. Ja as areas com vegetacao de encosta apresentaram valores de SAVI que variaram entre 0.130 e 0.210. Em geral, ocorreu um aumento do Albedo, entre 27 de agosto de 1992 e 12 de setembro de 2003 e na bacia hidrografica do rio Moxoto. No geral as areas mapeadas como areas de solo exposto e/ou atividades antropicas apresentaram uma diminuicao na densidade da cobertura vegetal e consequentemente aumento nos valores de albedo e temperatura.

Vitis vinifera SPECTRAL RESPONSE TO THE INCREASE OF CO2

Hyperspectral remote sensing (HRS) is a useful method to monitor spectral changes in vegetation. HRS contains significant spectral information for detecting plant stress. The specific aims were: (1) to assess the changes in Vitis vinifera plant chlorophyll content due to the leakage of CO2 into the plant-air environment, and (2) to analyze an vegetation index derived from the first derivative reflectance values for use in detecting Vitis vinifera plant stress due to elevated concentrations of air CO2. Spectral reflectance was measured between 336 and 1045 nm with a spectral resolution of 1 nm, covering visible and near-infrared portions of the electromagnetic spectrum. The amount of chlorophyll decreased about 50% in the open top chamber modified (OTC modified) + CO2 injection when compared to natural condition. The difference in chlorophyll between OTC modified + no CO2 injection and natural condition was 24%. The concentration of chlorophyll a and b decreased and concentration of carotenoids increases of Vitis vinifera in initial stage of growth, with increase in CO2 to 550 ppm. In the end, the remote sensing hyperspectral presents itself as a great tool to assist in studies of global climate change and its impacts on the biomes of the world.

HOMOGENEIZAÇÃO DA PRECIPITAÇÃO PLUVIOMÉTRICA NA BACIA HIDROGRÁFICA DO RIO GOIANA - PE, COM MÉTODO DE ANÁLISE DE AGRUPAMENTO

O objetivo deste estudo e usar o metodo de analise de agrupamento de Ward para mapear a pluviosidade homogenea na bacia hidrografica do rio Goiana-PE e posteriormente verificar os principais fatores fisicos, internos a bacia, que influenciam na espacializacao da chuva. Como medida de dissimilaridade foi empregada a distância euclidiana. Os resultados mostraram que a bacia hidrografica do rio Goiana possui tres regioes pluviometricamente homogeneas e que estao fortemente influenciadas pelos fatores maritimos (longitudinais) e topograficos. Busca-se com estes resultados ampliar a difusao deste metodo entre os trabalhos envolvendo a Geografia e as ciencias afins e contribuir com posteriores diagnosticos que envolvam a dinâmica climatica nesta bacia.

Spectral Reflectance Characteristics of Laboratory-Grown Salt Crusts on Silty Clay and Sandy Soils

Salinization of soils has led to the loss of cropland and represents a major threat to food production. Hyperspectral imaging may prove to be useful for characterizing the spectral behavior of salt-affected soils but the methodology needs to be better evaluated. In this study, we characterized the spectral behaviors of four types of chloride salt crusts [calcium chloride dehydrate, magnesium chloride dehydrate, potassium chloride, and sodium chloride (CaCl2·2H2O, KCl, and NaCl)] formed in the laboratory. We found that (1) as salt concentration increased, the reflectance intensity decreased for both soil types, and the decreases were especially pronounced for the soils leached with the CaCl2·2H2O and MgCl2·2H2O solutions; (2) soil texture had little if any effect on reflectance; and (3) reflectance intensity decreased in the order CaCl2·2H2O < MgCl2·2H2O < KCl < NaCl. By clarifying the spectral behavior of chloride salt crusts on soils, our work demonstrates hyperspectral imaging may differentiate some types of salts and determine relative salt concentrations.