Study looks at road construction impacts on Brazilian Amazon

A study of the Brazilian Amazon shows more than 30,000 miles of roads -- a major factor in deforestation and habitat loss -- were built in just three years. Researchers, including two scientists from Imperial College London, said the way in which road networks develop is still poorly understood and studies like theirs will help combat future deforestation by allowing for more accurate predictions of where it might occur. Although roads often occupy less than 2 percent of a country's land surface, they may have an ecological impact on an area up to 10 times as large, they said. "Knowing where the roads are and the speed at which they are built is key to predicting deforestation," researcher Rob Ewers said in an Imperial College London release Monday. "An understanding of road networks is the big missing gap in our ability to predict the future of this region." The researchers, using road maps and satellite imagery to track the evolution of the Brazilian Amazon road network between 2004 and 2007, found roads spread most quickly in regions with high economic growth, as well as in areas where new settlements were being built. But once a region had an extensive network of roads in place, they found, the rate of building slowed down. The study, published in the journal Regional Environmental Change, was conducted in collaboration with IMAZON, the Amazon Institute of People and the Environment.