Student - January 29, 2009

ROUND THE WORLD IN EIGHTEEN BILLION PIXELS

Just imagine, you’re an African farmer and you want to find out more about your own piece of land. What is the soil like and how can you get the best out of it? You pick up your GSM and consult the digital GlobalSoilMap. A few seconds later, the information you want appears on the screen.

That’s still science fiction at the moment. But it may not be in a couple of years’ time, thinks Alfred Hartemink of the Wageningen ISRIC – World Soil Information. ‘It’s just around the corner,’ he says.

Hartemink is project leader of the new digital GlobalSoilMap, a large-scale project that aims to put the whole world into a digital soil map. No such map exists yet, he explains. Hard to imagine in this little country where every square meter has been mapped. But it’s not like that everywhere – far from it. The bigger the country, the less information about the soil there is, according to Hartemink. To say nothing of Africa, where the need for data about the soil is enormous. ‘There is a tremendous hunger for soil science information – among foresters, agriculturalists, hydrologists, climatologists, biologists and so on. There’s so much going on at all levels.’ Hartemink sees this as a ‘soil science renaissance’. The new map links a fixed set of soil characteristics to Nasa satellite maps with a resolution of nineteen by nineteen metres. ‘Pixels of thirty by thirty metres would be even better, but they are not yet available for the whole world.’ The result is a digital map with eighteen billion pixels, quantifying the carbon, water, clay and specific gravity of every inch of ground. ‘That may not seem like many characteristics, but from those four we can work out a lot of things.’

In Africa especially, a lot of new measurements are being taken on location. The rest are being extrapolated from existing databases and maps, because a map like this costs a fortune to produce. Hartemink estimates that it will cost 150 to 200 million dollars to map the whole world. Eighteen million has already been donated by the Gates Foundation and AGRA, the Alliance for a Green Revolution in Africa. This contribution is primarily intended for the African digital soil map. And this first phase of the global project was launched in Nairobi recently. The global project will be launched in New York in February, and several leading lights from Wageningen will probably attend.

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