The U.S. Department of Agriculture recently released a revised National Resource Inventory (NRI) that outlines the nation's land use trends.
NRI is a statistically based survey that has been designed and implemented using scientific principles to assess conditions and trends of soil, water and related resources on non-federal lands in the United States.
NRI data is tracked, gathered and categorized annually, while trend analysis is published every five years. "We have been producing NRI reports since 1982 and have released five reports," said Cameron Loerch, Colorado NRCS state soil scientist. "The information we get from these reports are vital to land-use planning."
Information available through the inventory describes the rate land is being developed across the country. The pace of development is estimated at 2.2 million acres a year, in the five-year period between 1992 and 1997, more than one and one-half times that of the previous 10-year period, 1982 to 1992 (1.4 million acres a year).
The revised 1997 NRI also includes additional information on wetlands. It indicates that 101,000 acres of wetlands were lost each year nationally, on the average, from l992 to 1997 and nearly 69,000 acres were gained, for an overall average annual net loss of 32,600 acres per year, due to all causes, including conversion for development, agriculture and forestland.
The report not only provides national statistics, but also statewide figures. It cites that in Colorado, more than 112,400 acres of land has been developed (converted from non-urban to urban) between 1992 and 1997 (a substantial amount of land converted to development in Colorado is due to an increase in small ranchettes and other developments, where only a portion of the land is classified as urban using NRI criteria). This increase is equivalent to 22,480 acres per year.
"This information is vital," said Stephen Black, Colorado NRCS state conservationist. "It allows us to track our progress, predict future outcomes and strategize for desired results."
The revised report also shows that over the last 15 years (1982 to 1997) the average soil erosion in Colorado has dropped 2%, but there is still a desperate need for conservation practices. "As an average, this is good," Black said. "Colorado farmers and ranchers deserve a lot of credit for the decrease. The sound conservation practices they implement are working. Excessive erosion due to wind continues to be a serious problem, so there is work to be done."
Other figures the report cites are that approximately 34% of the cropland in Colorado is irrigated and 42% of the pastureland is irrigated. The total land in Colorado that is irrigated is 3,458,800 acres.
The Natural Resources Conservation Service, in cooperation with the Iowa State University Statistical Laboratory, conducts the NRI, using more than 800,000 scientifically selected nationwide sample sites. It provides data on land cover and use, soil erosion, prime farmland soils, wetlands, habitat diversity, selected conservation practices and related resource attributes.
Data collected in 1997 enables an analysis of trends extending over 15 years. NRCS is working cooperatively with Iowa State University to provide new NRI data that will cover the period 1982 to 2000. These results will be announced in early 2002. The agency is implementing an annual inventory process, as well as working to develop a multi-agency integrated inventory approach.