Satellite imageries to count poppies in Afghanistan

Satellite imageries to count poppies in Afghanistan

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A new U.N. report claims that Afghan opium production skyrocketed over the past year. The area of the country planted with Papaver somniferum—the poppy that secretes opium as a milky -white goo — rose 64 percent, to 323,701 acres. The crop yielded 4,200 tons of opium, just shy of the record of 4,600 tons set in 1999. Since drug lords are understandably cagey about their operations, how did the United Nations obtain those figures?

In part by analyzing satellite imagery, and in part—as dicey as it sounds—by sending surveyors out to interview villagers in opium-rich areas. High-resolution images from two satellites, Ikonos-2 and SPOT 5, were studied for evidence of poppy cultivation. The Ikonos photos covered the 10 Afghan provinces that grew approximately 90 percent of the nation’s Papaver somniferum in 2003. In each province, Ikonos took two images of several 100-square-kilometer plots—one before the annual harvest and one afterward. This was done to ensure that wheat fields were not mistaken for poppy fields. The analysts then extrapolated countrywide figures from these samples.

The lower-resolution SPOT 5 images, meanwhile, covered only the province of Nangarhar. But because the satellite’s photos are more affordable than those of Ikonos, it was able to capture images of the entire province. The estimated poppy coverage found in the SPOT 5 images was then compared to the estimate extrapolated from the Ikonos sample of the province. The two sets of images led to estimates that were within 7 percent of each other, a gap which is considered almost negligible in this type of analysis.