In this monthly feature, we span the globe to examine Our Changing Landscape with time series of medium resolution RapidEye satellite imagery. The RapidEye archive dates back to late 2008 and already contains more than 3 billion square kilometers of data. This month, we travel to the Amazon Rainforest and explore changes in forest cover in the state of Pará, Brazil.
The RapidEye Constellation
RapidEye is a constellation of five 5-meter medium resolution satellites each offering five spectral bands of information. The RapidEye constellation offers a daily revisit time to every location on the planet with a huge footprint that is 77-km wide. The data is priced competitively with a base price of $1.28 per square kilometer for all five spectral bands – academics receive a discount on this price. RapidEye adds a fifth band, the red edge, to the ‘traditional’ multispectral set of blue, green, red and near-infrared (NIR). The additional spectral data available in the red edge band allows users to extract more useful land ‘information’ than can be from traditional 4-band imagery sources. When RapidEye imagery is ordered as a Level 3A Orthorectified product, images from multiple dates are extremely well registered, making it the ideal data source for Our Changing Landscape.
Deforestation in Pará, Brazil
For some time now, Brazil has been home to one of the strongest and most rapidly growing economies in the Southern Hemisphere. And as its economy blossomed, so too did clearing of one of our world’s most important natural resources, the Amazon Rainforest, reaching a peak in 2004. Since that time, deforestation in Brazil plummeted nearly 80% while the economy grew 40%, suggesting that for the first time in the country’s history, economic growth has not been coupled with and spurred by the clearing of the Amazon. There are multiple factors that help to explain this promising trend, including increased environmental regulations and monitoring by the Brazilian government; heighten environmental sensitive among the citizens and companies of the region; and global macroeconomic trends that make the export of timber not as profitable as it once was.
Today, the majority of Brazilian deforestation appears to be tied to five key activities. The leading activity is clearing forests for cattle ranching as Brazil is the world’s largest exporter and producer of beef. In the past, squatters were encouraged to move into the Amazon and settle new lands (i.e. clear forests) for subsistence farming; however, this trend has slowed in the past ten years as government support for this policy has waned. As government support for the expansion of subsistence farming has waned, its support of large infrastructure development projects such as damns and highways that clear massive tracts of forest at once has waxed. And as this infrastructure is built into remote regions of the Amazon, commercial agriculture operations and illegal logging spring up along newly built highways, clearing more forest lands. Historically, Pará has long been one of the most deforested states in Brazil and continues to be to this day. The series of 5-meter RapidEye images from Pará, Brazil below shows how rapidly deforestation can occur after relatively stable periods of forest cover.
In the image above you see an animation of deforestation in Pará, Brazil. This stack of three 5-meter RapidEye images was collected on 8/20/2009, 6/17/2011 and 8/14/2011. While you can see that forest cover declined from 2009 to June 2011, from June to August 2011, deforestation was significant as an area covering more than 60 acres was cleared in less than two months. (Images Courtesy: RapidEye)
If you would like to find out more about using RapidEye for your academic studies, engineering projects or any landscape analysis, let us know at [email protected] or (303) 993-3863.