In an article released late this month in Environmental Research Letters, authors Mark Broich, Matthew Hansen, Fred Stolle, Peter Potapov, Belinda Arunarwati Margono, and Bernard Adusei examined interannual forest cover loss on the Indonesian islands of Sumatra and Kalimantan from 2000 to 2008 using a combination of Landsat ETM+, MODIS, and SRTM data.

Forest cover loss in Sumatra between 2000-2008

Forest cover loss in Sumatra between 2000-2008

The researchers found that forest cover loss for the two islands during this time period totaled just under 21,000 square miles. This amount of land—nearly the size of West Virginia—accounted for 5.3 percent of the land area of the two islands, and some of the deforestation occurred in areas where forest clearing is prohibited or restricted.

Using this multi-sensor approach to map forest loss, the researchers were able to decipher that the deforestation rate increased between 2000 and 2006, peaked, and then began to decline. This work demonstrates that regular annual mapping yields a more accurate assessment of forest loss trends than a single national estimate.

A multi-sensor satellite approach, as shown in this study, could provide accurate forest cover information to national policy makers attempting to reduce greenhouse gas emissions as part of recent international agreements to incentivize forest conservation.

This work was funded by the NASA Land Cover Land Use Change program.

Mark Broich et al. (2011) Remotely sensed forest cover loss shows high spatial and temporal variation across Sumatera and Kalimantan, Indonesia 2000–2008. En vir omental. Research Letters, vol. 6. doi:10.1088/1748-9326/6/1/014010 [external link]