DETER’ system – Deforestation Detection in Real Time from National Institute for Space Research (INPE), confirms that 323km2 from Legal Amazon had shallow cut or progressive degradation during July/08, when satellites could observe 81% of the region. This is the smallest result since March 2008, when the system detected 145km2, although in that month only 22% from Amazon was seen by satellites due to the region has been covered by clouds. In April, May and June, DETER pointed 1124, 1096 and 870 km2, numbers that could indicate the tendency for the diminution.
In July, from those 323 km2 checked, 235.6km2 are located in Para, however in Mato Grosso was found only 32,7 km.
The 323km2 distribution deforestation from July 07 to 31, 2008
DETER’system data concerning August month will be published on September 29th
Avaliação
INPE prepared a report with qualification data from LANDSAT and CBERS satellite images that presented a better space resolution. The analysis report, available at www.obt.inpe.br/deter, shows that 97.3% of the areas pointed by DETER were confirmed as deforested. We can see that 212 were evaluated as alert deforestation, which correspond to 244km2 (75%) of the total area of the polygons (323km2) indicated by DETER in July.
The alerts indicated deforestation by shallow cut (79,5%) mainly, and by forestall degradation of high intensity (14,4%). About 4% of the alert showed moderate intensity deforestation and only 2,7% did not show any evidence of image deforestation. These results prove that the use of DETER system was necessary to detect the polygons in all band’ size, so that in areas bigger than 2km2 (200ha) the confirmation index was 100%.
DETER
Working since 2004, DETER was created by INPE as an alert system to support surveillance and deforestation control. Both shallow cut and areas in process of deforestation are mapped. It is possible to detect only deforestation polygons with an area larger than 25 hectares due to spatial resolution (DETER uses MODIS sensor data from Terra satellite, and WFI sensor data from China Brazil Earth Resources Satellite -CBERS, with spatial resolution of 250 meters). Due to cloud coverage, not all deforestation larger than 25 hectares is able to be identified by the system.
You can check all information about deforestation published by INPE at http://www.obt.inpe.br/deter/. At DETER’s page a consult reveals the system had registered 8147km2 of new deforestations in the last 12 months (from August 2007 to July 2008) while between August 2006 and July 2007 were identified 4820km2. However, it is good to emphasize that these data do not correspond to the annual rate deforestation, which is measured by PRODES, a more detailed system that considers only shallow cut deforestation , or rather, the deforestation in its final phase.
More information: http://www.inpe.br/ingles/news/news_not21.php
