Terra-i, a real-time deforestation tracking system that combines satellite coverage with on-the-ground processing and mapping has launched in advance of the United Nation's environmental conference in Brazil.

An international team has designed the system to track logging and other activities that strips trees and vegetation from the land in Latin America. Deforestation is having a significant effect on the ecology of Central and South America, as well as on its culture, finances, and health, due to its effect on the availability of clean water.

This system has to potential to affect government policy "by drawing attention, close to real time, to declines in deforestation associated with policies that are working (such as protected area designation, sustainable development projects) or to highlighting surges in deforestation and thereby helping to pinpoint the causes of those," Dr. Mark Mulligan, the project's supervisor, told Ars.

The team is led on the ground by Louis Reymondin, a doctoral student in Geography, like Mulligan also from King's College London. Columbia's International Center for Tropical Agriculture, Switzerland's School of Business and Engineering Vaud (HEIG-VD), and the Nature Conservancy are also taking part.

The system uses MODIS NDVI (Normalized Difference Vegetation Index) data gathered by moderate resolution imaging spectroradiometers carried by NASA's Terra (EOS AM) and Aqua (EOS PM) satellites.

"There are a number of other systems based on MODIS data but none have both the 16-day period and cover an entire continent as Terra-i does," Mulligan said.

So far the system has shown that deforestation has increased in Caquetá, Columbia by 340 percent since 2004, and the Gran Chaco region of Paraguay, the second most forested area in South America, has lost over a million hectares of forest.

Mulligan, an attendee at the upcoming Rio+20 United Nations Conference on Sustainable Development, described the development of a system that would distinguish between seasonal changes and permanent ones.

"We developed a computational neural network and 'trained' it with data from 2000-2004 to recognise the normal changes in vegetation greenness due to seasonal variation in rainfall in different areas. The network now recognises where and when greenness suddenly changes well beyond these normal limits as a result of deforestation. The system runs on data for every 250 square metres of land from Mexico to Argentina shortly after the data comes in from MODIS and highlights every 16 days the pixels that significantly change, writing these results to Google Maps for easy visualisation."

The Terra-i system is scaleable and the developers have plans to extend its coverage. Brazil has had a system to track deforestation in place since 2008. Now all of Latin America has it. Soon, if things proceed apace, the system will cover all tropic regions.

"As we approach Rio+20 where the world will define the targets that will guide us along the road to a more sustainable development, it is critical that we deploy the appropriate tools to carefully monitor and manage our landscapes," said Mulligan. "We need to ensure that we maintain enough farmland to feed the nine billion people to come, but we must also have protected natural landscapes that provide clean water, a stable climate, a refuge for biodiversity, and space for increasingly urbanised populations to experience and appreciate the wonders of nature."