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           <div class='source_table'>
  -          <p>Drag the handle to adjust the minimum tree cover canopy (TCC) density for the visualization and analysis of UMD tree cover and tree cover loss. TCC density represents the estimated percent of a UMD pixel that was covered by tree canopy in the year 2000, as determined from the analysis of satellite imagery. For the tree cover loss data, TCC density therefore corresponds to the density of tree cover <u>before</u> loss occurred. For example, if you select 25% as the minimum TCC density, you will only see tree cover loss pixels for which the original tree cover density was greater than 25%.</p>
  -          <p>Adjustments to the minimum TCC density only affect UMD tree cover and tree cover loss data layers. This feature does not pertain to UMD tree cover gain or to other GFW data layers or statistics. UMD tree cover gain is displayed with a set minimum TCC density greater than 50%. The minimum TCC density cannot be changed independently for tree cover and tree cover loss. A change made to one data layer will immediately take effect in the other.</p>
  +          <p>Drag the handle to adjust the minimum tree cover canopy (TCC) density for the visualization and analysis of Hansen/UMD/Google/USGS/NASA tree cover and tree cover loss. TCC density represents the estimated percent of a pixel that was covered by tree canopy in the year 2000, as determined from the analysis of satellite imagery. For the tree cover loss data, TCC density therefore corresponds to the density of tree cover <u>before</u> loss occurred. For example, if you select 25% as the minimum TCC density, you will only see tree cover loss pixels for which the original tree cover density was greater than 25%.</p>
  +          <p>Adjustments to the minimum TCC density only affect Hansen/UMD/Google/USGS/NASA tree cover and tree cover loss data layers. This feature does not pertain to Hansen/UMD/Google/USGS/NASA tree cover gain or to other GFW data layers or statistics. Hansen/UMD/Google/USGS/NASA tree cover gain is displayed with a set minimum TCC density greater than 50%. The minimum TCC density cannot be changed independently for tree cover and tree cover loss. A change made to one data layer will immediately take effect in the other.</p>
             <p>This feature is also available for statistics within the country profiles and rankings. However, the adjustment made to the visualization and analysis through the map view will not be automatically reflected in other areas of the website. To adjust the minimum TCC density within the country and country rankings pages, click on the settings icon.</p>
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positive.code: 
      <p>To learn more, visit the <%= link_to 'Forest Change tab', "#{sources_path}#forest_change" %> on the Data page.</p>
  
      <p><strong>Figures:</strong> UMD/Google circle graphs, 2012 tree cover, all global overview graphs and rankings</p>
  
      <h3 class='overview_title'>European Space Agency (GlobCover)</h3>
      <p>Data from the European Space Agency’s GlobCover was used to visualize tree cover on the country pages. As stated on the <a href='http://due.esrin.esa.int/globcover/' target='_blank'>ESA website</a>, GlobCover is an initiative which began in 2005 in partnership with a number of organizations. The aim of the project was to develop a service capable of delivering global composites and land cover maps using input observations from the 300m MERIS sensor on board the ENVISAT satellite mission. ESA makes available the land cover maps, which cover 2 periods: December 2004 - June 2006 and January - December 2009. To learn more, visit the <a href='http://due.esrin.esa.int/globcover/' target='_blank'>GlobCover website</a> or <a href='http://due.esrin.esa.int/globcover/LandCover2009/Globcover2009_V2.3_Global_.zip' target='_blank'>download the 2009 GlobCover map</a>.</p>
  
negative.code: 
                <p>When zoomed out (< zoom level 13), pixels of gain are shaded according to the density of gain at the 30 x 30 meter scale. Pixels with darker shading represent areas with a higher concentration of tree cover gain, whereas pixels with lighter shading indicate a lower concentration of tree cover gain. There is no variation in pixel shading when the data is at full resolution (≥ zoom level 13).</p>
  
                <p>A validation assessment of the 2000 – 2012 Hansen/UMD/Google/USGS/NASA change data was carried out independently from the mapping exercise at the global and biome (tropical, subtropical, temperate, and boreal) scale. A stratified random sample (for no change, loss, and gain) of 1500 blocks, each 120 × 120 meters, was used as validation data.  The amount of tree cover gain within each block was estimated using Landsat, MODIS, and Google Earth high-resolution imagery and compared to the map. Overall accuracies for gain were over 99.5% globally and for all biomes. However, since the overall accuracy calculations are positively skewed due to the high percentage of no change pixels, it is also important to assess the accuracy of the change predictions. The user’s accuracy (i.e. the percentage of pixels labelled as tree cover gain that actually gained tree cover) was 87.8% at the global level. At the biome level, user’s accuracies were 81.9%, 85.5%, 62.0%, and 76.7% for the tropical, subtropical, temperate, and boreal biomes, respectively.</p>
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