Gustavo Macedo de Mello Baptista

Avaliação dos processamentos de crosstalk e de correção atmosférica em dados ASTER para identificação da relação mineralógica caulinita/(caulinita + gibbsita) em solos no município de São João d'Aliança (GO)

The aim of this study was to analyze the influence of atmospheric correction and crosstalk in the spatial relationship of kaolinite/(kaolinite + gibbsite) in tropical soils through the application of the spectral index RCGb scale, in ASTER-SWIR L1A and L1B images, and in products on-demand AST_07 and AST_07XT, acquired on October 24, 2001. Atmospheric correction routines FLAASH and QUAC and the CRSTK30 software were used to correct for the crosstalk effect. The results were analyzed according to four approaches: comparing the behavior of RCGb scale and RCGbATG transects, analysis of the RCGb scale image of sliced values and analysis of the RCGb scale image and statistical analysis of the similarity between the values of the RCGb scale and RCGbATG transects through the Mann-Whitney statistical test. The routines FLAASH and QUAC hampered the identification of environments and mineralogical relationship. The combination CRSTK30-FLAASH impaired the identification of environments, as well as the relationship mineralogical and the behavior of the RCGb scale transect. The combination CRSTK30-QUAC provided better results in terms of the statistical similarity in relation to the results of the processing without corrections. The results indicated that the products on-demand AST_07 and images L1B converted to reflectance with crosstalk correction and atmospheric correction (QUAC) are the most appropriate, in this order.

Wetland nutrient retention and multitemporal growth – Case study of Riacho Fundo’s Wetland

Abstract Aim: The aim of this research was to evaluate the nutrient retention of Riacho Fundo’s wetland in controlling Lake Paranoa (Brasilia, Brazil) eutrophication analyzing its ability to retain nitrogen and phosphorus. Furthermore, the article aimed at verifying the multitemporal growth rate of Riacho Fundo’s wetland. Methods Five sampling points were distributed along the wetland, from its beginning to its outflow into Lake Paranoa. Twenty-five field campaigns during periods of drought and rain from November 2011 to October 2012 with intervals of fifteen days were accomplished. The parameters total nitrogen and total phosphorus were analyzed and for comparison between the sampling points a non-parametric statistical analysis was performed and the efficiency of retention of these parameters between input and outputs of the wetland was calculated. For the analysis of multitemporal pace of growth in the area of wetland, water area and was estimated by processed satellite images of the years 1973, 1985, 1995, 2005 and 2011. Results The general behavior of the analyzed nutrients was decay between the entry point and exit point of showing an overall average retention of nitrogen 36.66% and 33.95% overall average total phosphorus. By image processing was possible to estimate that the surface of the lake was lost 0.5273 km2 or 84.07% of the initial area in the range of 38 years. Conclusion Despite having lost water area, Lake Paranoa gained a natural filter that retains nutrients that could be being invested in it and so can cause eutrophication of its waters. Thus, the wetland provides an ecological service of water treatment and preservation of aquatic and terrestrial Lake Paranoa life and the wetland should be considered as an importanttheme in Lake Paranoa management.

Séries temporais do sensor Modis para mapeamento de áreas irrigadas em bacias hidrográficas do Nordeste brasileiro

The objective of this work was to evaluate the applicability of time series of the enhanced vegetation index (EVI), from the moderate resolution imaging spectroradiometer (Modis), in the mapping of irrigated areas in the Northeastern region of Brazil. Annual time series from 2006 to 2015 were classified with the iterative self-organizing data analysis technique (Isodata) algorithm, generating a binary map of irrigated and nonirrigated areas for each year. In the Sertão region, the classification showed an average kappa coefficient of 0.66, underestimating the irrigated area by 7.6%, compared with data of the 2006 agricultural census. In regions more humid than the Sertão, such as Agreste and Zona da Mata Nordestina, the methodology showed limitations to distinguish irrigated areas from natural vegetation, presenting average kappa coefficients of 0.26 and 0.00, respectively. The EVI time series from Modis are applicable for the mapping of irrigated areas in the Sertão of the Northeastern region of Brazil.

Vegetation Cover Development Resulting from Different Restoration Approaches of Exploited Mines

The vegetation cover development is an essential step towards the restoration of the ecosystems. In this work, we applied remote sensing to evaluate the temporal development of vegetation cover on exploited mines revegetated with five approaches: natural regeneration, tree plantation, cultivation of trees + herbs, topsoil replacement + tree plantation, and sewage sludge incorporation into mining substrate. Results showed that the natural regeneration approach would require a secular time to provide satisfactory vegetation cover on the exploited mine. Tree plantation required fifteen years to provide 80% of vegetation cover. The use of topsoil + trees or the incorporation of sewage sludge into mining substrates achieved the fastest development of vegetation cover (2.5-5 years) and the highest percentages of revegetated surface (80-95%). However, the floristic composition of vegetation covers is as important as their development, and some restoration approaches are reported to stimulate weed invasion while others prevent it.

Preliminary assessment of ALOS/PALSAR images for the international roughness index estimation

This article evaluates the relationship between SAR backscattering coefficients and the International Roughness Index (IRI). We used full-polarized ALOS/PALSAR amplitude images and field data gathered using laser sensors on-board of vehicles. We also evaluated LANDSAT-5/TM images for comparison. The study area is located in Brazils Federal District. Simple regression was used for quantitative analysis employing Pearsons correlation coefficients (r) and determination coefficients (r2). The HH polarized image yielded an r value of 0.5040 and a r2 value of 0.2541. The HV polarized image obtained an r value of 0.4824 and a r2 value of 0.2327 while the VV polarized image reached an r value of 0.4382 and a r2 value of 0.1920. All r2 values were considered significant. Those results show that there is an important relationship between SAR backscattering and IRI. Considering that, new researches will be conducted using high spatial resolution SAR sensors and different wavelengths.

Evaluation of the environmental importance of Riacho Fundo's wetland to Paranoa lake and neighboring communities

regarding water quality. One of its main tributaries, the Riacho Fundo, has many solids and sediments in suspension, which could be cause for great concern, but a wetland naturally was formed at the downstream, object of this study. Using images of the airborne sensor of R-99 aircraft, Multispectral Scanner (MSS), and applying different resources of geoprocessing including Normalized Difference Vegetation Index (NDVI), Photochemical Reflectance Index (PRI) and Spectral Angle Mapper (SAM) was investigated the environmental importance of the wetland to the Paranoa Lake and neighboring communities, especially regarding to three aspects: suspended solids retention, carbon dioxide sink and thermal comfort. The results proved that the wetland contributes significantly to the improvement of water quality of Paranoa Lake, because it is able to retain the suspended solids coming from upstream, and also cooperates with the oxygen generation and thermal comfort, because it sinks carbon more strongly than the areas of margins and appears colder than the edges.

ANÁLISES ESPECTRAIS DA VEGETAÇÃO COM DADOS HYPERION E SUA RELAÇÃO COM A CONCENTRAÇÃO E O FLUXO DE CO2 EM DIFERENTES AMBIENTES NA AMAZÔNIA BRASILEIRA

A modelagem espectral e uma das ferramentas importantes para a determinacao de estimativa de parâmetros biofisicos de um local. Correlacionar a concentracao e o fluxo de dioxido de carbono, por meio de medicoes indiretas e um grande avanco na area das geociencias. A metodologia desenvolvida para o sequestro florestal de carbono CO2flux, CO2fluxEVI e CO2fluxEVI2, a partir do sensor Hyperion envolveu ambientes naturais e antropicos, tornando-o eficaz quando associada a variabilidade de ecotipos existentes na Amazonia Brasileira. Resultados desse estudo apontaram que os indices NDVI, EVI e EVI2 podem compor a estrutura do indice de sequestro florestal de carbono, CO2flux. Entretanto, fez-se necessario avaliar a potencialidade e comparacao dos indices em relacao a deteccao do sequestro florestal de carbono, associado as medicoes diretas de CO2 nas torres micrometeorologicas. Apos o processamento das imagens hiperespectrais e analises estatisticas dos indices sugeridos pode-se inferir que o CO2flux com a utilizacao do NDVI tem melhor ajustamento, quando associado aos dados de concentracao de CO2 (ppm) medidos no topo das torres, e com os dados de fluxo (mol.m-2.s-1), uma vez que as correlacoes possuem similaridades e sao estatisticamente significativos com os dados do sensor Hyperion.