Coca Cultivation and Eradication Estimates in Colombia
GAO-03-319R: Published: Jan 8, 2003. Publicly Released: Jan 8, 2003.
In a letter to us, Congress noted the differing coca estimates for Colombia. In subsequent discussions, we agreed to determine the (1) purposes of the Crime and Narcotics Center's (CNC) coca cultivation estimate and the Department of State's Bureau for International Narcotics and Law Enforcement Affairs, the Office of Aviation's coca eradication estimate in Colombia and (2) status of actions to implement the Executive Office of the President, Office of National Drug Control Policy (ONDCP) study's recommendations.
The coca cultivation estimate prepared by CNC and the coca eradication estimate prepared the Office of Aviation in Colombia serve different purposes and cannot be readily reconciled to one another because of differences in their respective methodologies. Annually, CNC develops cultivation estimates for coca, opium poppy, and marijuana in drug-producing countries around the world. These are published each March as part of the President's determination whether to continue providing U.S. assistance to major drug-producing and -transit countries. To prepare its estimates, CNC analyzes black and white high-resolution photographs taken primarily from satellites covering a representative sample of the target country's known or suspected drug-growing areas. This allows CNC to estimate illicit drug cultivation for the entire country. In Colombia, these images are usually taken, weather permitting, between November and January of each year. Because these cultivation estimates are used by other U.S. government agencies to help determine the amount of illicit drugs available for consumption in the United States, CNC focuses on identifying fields of healthy coca plants with leaves that are suitable for processing into cocaine. As part of its support for the Colombian National Police, the Office of Aviation uses airborne digital cameras to photograph coca fields for targeting aerial spraying and, afterwards, to help estimate the number of hectares eradicated. Through computer analysis, the Office of Aviation analyzes the light reflecting off the vegetation to identify coca. The digital photos can be taken anytime weather permits and are targeted over areas where the Colombian National Police intends to conduct or has conducted aerial eradication operations. Also, because the Office of Aviation wants to identify any coca fields for aerial eradication, it includes coca seedlings and mature, damaged, and dead plants in its definition of a coca field. The June 2002 ONDCP study recommended, among other things, that CNC and the Office of Aviation reconcile their definitions of a coca field, develop an error rate for each estimate, and enhance the technologies used for developing the respective estimates. Both CNC and Office of Aviation officials said they are in the process of implementing many of these recommendations, though the Office of Aviation said that some would require additional funding. CNC noted that it would have many of the changes necessary completed in time for its 2002 coca cultivation estimate.