Aplicação Do Índice Da Vegetação Por Diferença Normalizada (Ndvi) Em Imagens Cbers 2b No Município De Botucatu-Sp

Abstract

RESUMOO objetivo do presente artigo foi testar a aplicação do índice de vegetação NDVI em imagens de satélite CBERS 2B, sensor CCD, em toda a área do município de Botucatu -SP. As imagens são datadas em 07/12/2008, sendo utilizada as bandas 3 e 4, que correspondem às faixas de vermelho visível e infravermelho próximo, respectivamente. Tais bandas são freqüentemente utilizadas em categorização de imagens de satélite para análises agrícolas e estudos ambientais. O índice de vegetação NDVI (Normalized Difference vegetation Index) é o indicador mais usado ultimamente, por reduzir parcialmente o efeito da topográfia, e apresentar uma escala de medida linear entre -1 e 1, onde o valor zero são designados como conjunto de pixel com ausência de vegetação (Ramos et. al., 2010). O NDVI retratou a condição e o grau de degradação sofrido na superfície do município de Botucatu, través da retirada da cobertura vegetal principalmente nas bordas da malha urbana e no setor norte, apresentando alvos com valores entre 0,10 e 0,30. Palavras-chave:Imagem de Satélite, NDVI, Sensoriamento Remoto. ABSTRACTThe purpose of this article was to test the application of vegetation index NDVI satellite images CBERS 2B CCD sensor in the whole area of Botucatu -SP. The images are dated 07/12/2008, bands 3 and 4 which correspond to bands of visible red, near infrared, being respectively used. Such bands are often used in categorization of satellite imagery analysis for agricultural and environmental studies. The vegetation index NDVI (Normalized Difference Vegetation Index) is the indicator most used lately, partially reduce the effect of topography, and present a linear measurement range between -1 and 1, where the zero value are designated as a set of pixel absence of vegetation (Ramos et. al., 2010). The NDVI portrayed the condition and the degree of degradation suffered on the surface of Botucatu, abeam the removal of vegetation cover mainly the edges of the urban area and in the northern sector, presenting targets with values between 0.10 and 0.30.

Geographic information systems in the delimitation of permanent preservation areas and vegetation index on the Jequitinhonha Valley municipality

“…The municipal see of Capelinha, also characterized by red tonality, is drained by the Areão stream, which has low NDVIs (-0.23454) in its banks, indicative of inappropriate use and occupation of the land in urban area, besides the rural zone. A similar situation was found by Rodrigues and Rodrigues (2012) who, using the NDVI to evaluate Botucatu's vegetation cover, found 0.1 NDVI for the urban area close to those agriculturally developed within the municipality. Comparing Figures 7 and 8, it is possible to state the importance of the PRNH for the region, since shades indicating low vegetation cover predominate in areas where there is no reserve, either in the urban center or in rural areas, a fact corroborated by fieldwork.…”

“…However, land uses that are very common in the region, such as agricultural crops, pasture, and forestry, cannot be considered as positive in terms of biodiversity conservation. This was also shown in Rodrigues and Rodrigues (2012), which studied the city of Botucatu, São Paulo state, Brazil, found low NDVI in most of the municipality, including marginal regions that were related to the region's agricultural expansion. Figure 7 shows some fragments in red tonality, especially in the central and northwest region of the municipality.…”

Sugarcane spatial-temporal monitoring and crop coefficient estimation through NDVI

“…Pixels with lower values, 0 to 0.05 range, received red color, representing exposed soil; pixels with variation from 0.05 to 0.26 received a salmon color (pinkish orange), representing a recently planted area, so that it is similar to the spectral behavior of exposed soil (Formaggio & Sanches, 2017), or even areas with some process of degradation (Rodrigues & Rodrigues, 2012); beige shade (close to white) was attributed to the range from 0.26 to 0.47, representing areas with little biomass; the set of pixels in the range from 0.47 to 0.69 received a light green color, representing areas with green but still scarce vegetation, which may be related to vulnerable health of the crop (not healthy or under any water deficit) or even to the process of maturation; and the set of pixels with highest values, from 0.69 to 0.90, received a dark green color, representing higher vegetative vigor of the crop.…”