Corrected Federal Data Crops Picture of Lost Lands

Valuable forests and agricultural land slipped under the wheels of the nation's sprawling commercial and residential juggernaut at a rapid rate over the last decade but not quite at as quickly as first believed, recently corrected federal data shows.

The Natural Resources Conservation Service, the land and water conservation arm of the U.S. Department of Agriculture, released the long-awaited update to its Natural Resources Inventory (NRI) last week.

The corrections showed that errors in the software that produced the detailed, state-by-state calculations of development of wetlands, agricultural lands, forests and other open spaces overestimated growth on non-federal areas in the five year period between 1992 and 1997 by 30 percent.

The first figures, released by Vice President Al Gore and Agriculture Secretary Dan Glickman in December 1999, put the amount of land developed over the period at nearly 16 million acres, or 3.2 million acres per year. The revised official figures, released Jan. 9 after almost ten months of recalculating numbers based on a chain of statistical missteps that were discovered last March, trim the five-year figure to11.2 million acres, just over 2.2 million acres per year.

Estimates of development on private, municipal and state lands in the United States dropped 7.1 million acres to a total of 98.3 million acres as of 1997, the last year included in the survey.

NRCS officials say they completed the update in mid-December but delayed its release in order to issue a good news package along with research from the U.S. Fish and Wildlife Service showing that the rate of wetland loss decreased 80 percent over the last decade.

But Jeff Goebel of NRCS's Resources Inventory Division, the office responsible for the NRI data, cautioned that the more conservative figures still revealed an alarming jump from patterns first measured in 1982.

"I'm a statistician, so from that respect this is a big change. But as far as the impacts of [growth], that's a different situation. It's still over a 50 percent increase from what took place over the previous decade," Goebel said Thursday by telephone from Ames, Ia., where NRCS staff were meeting with the statisticians from Iowa State University who conducted the inventory.

NRCS literature touts the NRI as "the most comprehensive database of its kind ever attempted anywhere in the world."

Launched under Congressional mandate in 1982, it gathers data from over 800,000 statistical sample areas on the growth and decline of cropland, pasture and rangeland, forests, wetlands and new development. It also monitors habitat diversity, soil erosion and irrigation patterns.

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