Estimating summer crops area using TM/Landsat-5 data from pre-planting season / Imagens TM/Landsat-5 da época de pré-plantio para a previsão da área de culturas de verão

AUTOR(ES)
DATA DE PUBLICAÇÃO

1998

RESUMO

Estimation of cultivated areas with agricultural crops is important for economic policy making. In Brazil, there is a lack of objective techniques for that purpose. Remote sensing seems to be valuable for crop acreage estimations in a large scale. However, cloud cover at the time of summer season has impaired the use of optical remote sensing images for evaluation of summer crops. An alternative is to use these data to evaluate objectively and in advance the area prepared to be cultivated with summer crops. In the present work multitemporal remote sensing techniques were used to estimate areas to be planted with annual summer crops in the municipalities of Sumaré, Hortolândia and Nova Odessa located in São Paulo State, for the crop calendar 1997/1998. Three TM/Landsat images from 1997 July 8, September 28 and October 14 were selected to perform multitemporal analysis using supervised (MAXVER) and unsupervised (ISODATA) classifications of original and transformed (NDVI) data. The accuracy of maps was determined using statistical sampling of ground fields. The quantification of classification error based on ground truth survey allowed corrections of the area estimates. The error matrix was used to improve the estimates of proportions-correct for each map category. It was shown that there was a very good score for the percentage of correct classification using the proposed techniques. Nevertheless, it was observed large differences in area estimation between the remote sensing techniques and the official estimations at the municipality level.

ASSUNTO(S)

índice de vegetação da diferença normalizada ndvi agricultura previsão de safra uso da terra landsat 5 mapeador temático (landsat) hortolandia (sp) culturas de verão sumare (sp) nova odessa (sp)

ACESSO AO ARTIGO

Documentos Relacionados