Cropland area estimates using Modis NDVI time series in the state of Mato Grosso, Brazil.

• Autor(a) principal: VICTORIA, D. de C.
• Data de Publicação: 2012
• Outros Autores: PAZ, A. R. da, COUTINHO, A. C., KASTENS, J., BROWN, J. C.
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da EMBRAPA (Repository Open Access to Scientific Information from EMBRAPA - Alice)
• Texto Completo: http://www.alice.cnptia.embrapa.br/alice/handle/doc/949316
• topic: Índice de vegetação; Máscara de culturas; Área cultivada; Transformada de Fourier; Cropland masks; Cultivated area; vegetation index

The objective of this work was to evaluate a simple, semi?automated methodology for mapping cropland areas in the state of Mato Grosso, Brazil. A Fourier transform was applied over a time series of vegetation index products from the moderate resolution imaging spectroradiometer (Modis) sensor. This procedure allows for the evaluation of the amplitude of the periodic changes in vegetation response through time and the identification of areas with strong seasonal variation related to crop production. Annual cropland masks from 2006 to 2009 were generated and municipal cropland areas were estimated through remote sensing. We observed good agreement with official statistics on planted area, especially for municipalities with more than 10% of cropland cover (R2 = 0.89), but poor agreement in municipalities with less than 5% crop cover (R2 = 0.41). The assessed methodology can be used for annual cropland mapping over large production areas in Brazil.