published a report in 2006 entitled “Eating Up the Amazon”.
This report contained evidence that soy cultivated in deforested
areas of the Amazon biome was exported to Europe and used to
feed chicken to produce the “McNuggets” (Greenpeace, 2006).
Given the impact of these actions on public opinion and the
questions of European clients about the origin of Brazilian soy,
the topic of deforestation began to be part of the soy traders'
agenda. In this way, NGOs and Brazilian soy traders initiated a
dialogue with the aim of defining a common agenda for
stopping the advance of soy into the Amazon rainforest
resulting in the Soy Moratorium that was signed on July 24.
2006. This agreement requires that all soy cultivated in
deforested areas (legal or illegal) after this date will not be
commercialized by any company linked to the Brazilian
Association of Vegetable Oil Industries (Associaçäo Brasileira
das Indástrias de Óleo Vegetal - ABIOVE) and the National
Association of Cereal Exporters (Associacdo Nacional dos
Exportadores de Cereais - ANEC). The Soy Moratorium has
been renewed annually and, since 2009, satellite images are
being used for monitoring soy cultivation in deforested areas
mapped by the Program for the Calculation of Deforestation in
the Amazon (Programa de Cálculo do Desflorestamento da
Amazónia - PRODES) (Rudorff et al., 2011).
The monitoring method is based on the EVI2 time series from
the MODIS sensor and the Crop Enhancement Index (CEI)
approach (Rizzi et al., 2009). At the same time, images with
improved spatial resolution from the AWIFS, LISS3, TM and
ETM+ sensors are used to better identify and delineate the soy
plantations within the deforested polygons (Rudorff et al,
2012). In some instances the deforestation date is contested by
the farmer and the visualization tool for EVI2 time series
developed by INPE (Freitas et al., 2011) is used, together with
TM images, to ensure the correct deforestation date whenever
there is a conflict between PRODES data and the farmer
argument. The visualization tool has been used to determine
the exact period in which deforestation occurred. In addition, it
allows the identification of various LUC patterns through the
seasonal analyses of terrestrial targets (Adami et al., 2012). In
this sense, the objective of this work is to use the MODIS/EVI2
time series to identify the LUC patterns and trajectories of
deforested areas within the Soy Moratorium context.
2. STUDY AREA
The study area is comprised by the Soy Moratorium polygons
selected during the fourth year of monitoring (crop year
2010/11). The selected polygons are from the PRODES years of
2007 to 2010 within municipalities that produced more than
5,000 ha of soy each in the previous crop year, and with an area
higher than 25 ha (Rudorff et al., 2011). Figure 1 indicates the
location of the Amazon biome and the states and municipalities
monitored in crop year 2010/11.
In crop year 2010/11, 3,571 polygons with a total area of
375,500 ha were monitored. Of this total, soy plantations were
found in 146 polygons corresponding to an area of 11,698 ha.
3. MATERIAL AND METHODS
The 3,571 deforested polygons were pre-evaluated with regards
to size and compactness criteria to exclude those polygons that
are too narrow or irregular. The compactness index (CI) is the
International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Volume XXXIX-B8, 2012
XXII ISPRS Congress, 25 August — 01 September 2012, Melbourne, Australia
ratio between the perimeter and the square root of the area of
the polygon. Higher IC values indicate more irregular
geometries, while lower IC values indicate more regular
geometries. A polygons to be selected should have IC less than
9 for area greater than 40 ha, or IC less than 6 for area smaller
than 40 ha. This procedure selected 1,971 polygons without soy
and 91 polygons with soy. A subsample of 50 polygons was
selected from each stratum: with and without soy.
80°W 70° W 60°W 50°W 40° W
N
10°N-
0°7 Es
109$4
e
20?S1 B
E
30984 5
=
©
Jn
40°S1
| | Selected Municipalities
Amazon Biome
50°87 Political Boundaries
[ 1 South America
Figure 1. Location of the study area. Adapted from Rudorff et
al. (2011).
In the next step, the subsampled polygons were evaluated with
respect to LUC homogeneity. Very heterogeneous polygons
represented an additional difficulty in the characterization of
LUC patterns and transitions after deforestation. For the
polygons without soy (first stratum), the evaluation was
conducted based on variations in the EVI2 temporal profile of
several MODIS pixels within the polygon. Each polygon
rejected in this evaluation phase was replaced by another
polygon. For the polygons with soy (second stratum) the
homogeneity was evaluated based on land use information
acquired from the aerial survey and available at:
<http://www.abtove.com.br/ss_relatoriousol0 br.asp>.
After the final selection of the 50 polygons from each stratum a
central pixel of each polygon was selected to perform the
MODIS/EVI2 time series profile analyses using the MODIS
Time Series Visualization for Land Use and Cover Analysis
(<https://www.dsr.inpe.br/laf/series/>) of the Remote Sensing
Time Series Virtual Laboratory developed to integrate a large
eM m8 00 0 à mo mA RO m Ya
