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2013-11-14. NASA-USGS Landsat Data Yield Best View to Date of Global Forest Losses, Gains.

posted Dec 3, 2013, 1:03 PM by Alan Gould
For GSS A New World View chapter 5. Excerpt:  The ravages of deforestation, wildfires, windstorms, and insects on global forests during this century are revealed in unprecedented detail in a new study based on data from the NASA-U.S. Geological Survey Landsat 7 satellite. The maps resulting from the study are the first to document forest loss and gain using a consistent method around the globe, at high resolution. They allow scientists to compare forest changes in different countries and monitor annual deforestation. With each pixel in a Landsat image showing an area about the size of a baseball diamond, researchers see enough detail to tell local, regional and global stories. Prior to this study, country-to-country comparisons of forestry data were not possible at this level of accuracy.  ...During the study period, Brazil cut its deforestation rate from approximately 15,400 square miles (40,000 square kilometers) per year to approximately 7,700 square miles (20,000 square kilometers) per year. "That's the result of a concerted policy effort to reduce deforestation, and it sets a standard for the rest of the world," Hansen said. ...The team found the deforestation rate in other countries increased.  Indonesia's deforestation rate doubled in the study period, from approximately 3,900 square miles (10,000 square kilometers) per year in 2000-2003 to more than 7,700 square miles (20,000 square kilometers) in 2011-2012. ...A different pattern of change appears in the southeastern U.S., where landowners harvest trees for timber and quickly plant their replacements. "Of this eco-region in the southeast, 30 percent of the forest land was regrown or lost during this period," Hansen said. "It's incredibly intensive. Trees are really treated like a crop in this region." In Alabama, Landsat also detected miles-long streaks of destroyed forest. When the researchers examined the year-by-year record, they found the damage occurred in 2011 after a violent tornado season. ...To view the forest cover maps in Google Earth Engine, visit: http://earthenginepartners.appspot.com/google.com/science-2013-global-forest - Source: http://www.nasa.gov/press/2013/november/nasa-usgs-landsat-data-yield-best-view-to-date-of-global-forest-losses-gains/. NASA Release 13-335.