TITLE:
Spectral Model for Soybean Yield Estimate Using MODIS/EVI Data
AUTHORS:
Anibal Gusso, Jorge Ricardo Ducati, Mauricio Roberto Veronez, Damien Arvor, Luiz Gonzaga da Silveira
KEYWORDS:
Remote Sensing; Coupled Model; Soy Yield; Forecast; Satellite Images
JOURNAL NAME:
International Journal of Geosciences,
Vol.4 No.9,
November
12,
2013
ABSTRACT: Attaining reliable and timely
agricultural estimates is very important everywhere, and in Brazil, due to its
characteristics, this is especially true. In this study, estimations of crop
production were made based on the temporal profiles of the Enhanced Vegetation
Index (EVI) obtained from Moderate Resolution Imaging Spectroradiometer (MODIS)
images. The objective was to evaluate the coupled model (CM) performance of
crop area and crop yield estimates based solely on MODIS/EVI as input data in
Rio Grande do Sul State, which is characterized by high variability in seasonal
soybean yields, due to different crop development conditions. The resulting
production estimates from CM were compared to official agricultural statistics
of Brazilian Institute of Geography and Statistics (IBGE) and the National
Company of Food Supply (CONAB) at different levels from 2000/2001 to 2010/2011
crop years. Results obtained with CM indicate that its application is able to
generate timely production estimates for soybean both at municipality and local
levels. Validation estimates with CM at State level obtained R2 = 0.95.
Combining all cropping years at municipality level, estimates were highly
correlated to official statistics from IBGE, with R2 = 0.91 and RMSD = 10,840
tons. Spatially interpolated comparisons of
yield maps obtained from the CM estimates and IBGE data also showed visual
similarity in their spatial distribution. Local level comparisons were
performed and presented R2 = 0.95. Implications of this work point
out that time-series analysis of production estimates are able to provide
anticipated spatial information prior to the soybean harvest.