Mapping Expansion of Soybean Cultivation with MODIS data
Ruth
DeFries, University of Maryland, rdefries@geog.umd.edu
(Presenting)
Douglas
Morton, University of Maryland, morton@geog.umd.edu
Matthew
Hansen, University of Maryland, mhansen@glue.umd.edu
Yosio
Shimabukuro, INPE, yosio@ltid.inpe.br
Liana
Anderson, INPE, liana@ltid.inpe.br
Ellen
Jasinski, University of Maryland, ejasinsk@pop900.gsfc.nasa.gov
Soybean cultivation is rapidly expanding in the southern portion of the Amazon basin, with potential implications for climate through changes in fire regimes, land cover, and size of clearings. While agricultural statistics document the area planted, spatially-explicit data are required to assess the implications of agricultural expansion on climate and ecosystem function. MODIS data at 250m spatial resolution and daily temporal resolution provide phenological information that distinguishes pasture from cropland. Soy fields display a distinct signature in the growing season with high values of the Enhanced Vegetation Index (EVI). In contrast, pasture displays lower EVI values throughout the year. Phenological patterns from both soy and pasture are distinct and separable from forest and cerrado. Here we show results from analysis of MODIS data for the years 2000 through March 2004 for Mato Grosso state. The results allow us to quantify the land area that has been converted to soy fields from 1) land previously cleared for pasture, 2) cerrado, and 3) forest. New soy fields are predominantly converted from land previously cleared for pasture, although a significant area is converted directly from cerrado and forest. The large size of new clearings in Mato Grosso (mean = 44 ha) reflect the high degree of mechanization in the region and the ability for land owners to deforest 50% of their properties in transition/ecotone forest types.
Submetido por Douglas Morton em 17-MAR-2004
Tema Científico do LBA: LC (Mudanças dos Usos da Terra e da Vegetação)