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Acres of Forest Land Converted to Developed Land, 1982-1997

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Description

This dot density map shows the total acreage of forest land converted to developed land from 1982 to 1997. Dots are aggregated by and placed randomly within 8-digit hydrologic units. Each red dot represents 2,000 acres of forest land converted to developed land. Developed land is a combination of urban and built-up areas and rural transportation land. There were 10,279,200 acres of land converted to developed land from 1982 to 1997. Areas with 95% or more Federal area are shaded gray.

Cautions for this Product:
Use this map only to identify broad spatial trends. Within an 8-digit hydrologic unit, dot counts represent total acreage, with an error of plus or minus one dot to account for remainders. Data are not available for Alaska or the Pacific Basin. Data for Puerto Rico and the U.S. Virgin Islands are aggregated by 6-digit hydrologic unit.



Sources

Source: National Resources Inventory, 1997
Distributor: USDA-NRCS-RIAD
Reliability:
NRI sample data are generally reliable at the 95% confidence interval for state and certain broad substate area analyses. Generally, analyses that aggregate data points by smaller geographic areas and/or more specific criteria result in fewer data points for each aggregation and therefore less reliable estimates. NRI maps reflect national patterns rather than site- specific information.


Layers

Aggregate Layer: Cross of State with 8 Digit Hydrologic Units and Federal Land
Other Layers Displayed: States, Rivers


Definitions

Developed land:
A combination of land cover/use categories, Urban and built-up areas, and Rural Transportation Land.

Forest land:
A Land Cover/Use that is at least 10 percent stocked by single stemmed forest trees of any size which will be at least 4 meters (13 feet) tall at maturity. When viewed vertically, canopy cover is 25 percent or greater. Also included are areas bearing evidence of natural regeneration of tree cover (cutover forest or abandoned farmland) and not currently developed for nonforest use. For classification as forest land, an area must be at least one acre and 100 feet wide. [NRI-97]

Rural transportation land:
A Land Cover/Use category which consists of all highways, roads, railroads and associated rights- of-way outside urban and built-up areas; including private roads to farmsteads or ranch headquarters, logging roads, and other private roads, except field lanes. [NRI-97]

Urban and built-up areas:
A Land Cover/Use category consisting of residential, industrial, commercial, and institutional land; construction sites; public administrative sites; railroad yards; cemeteries; airports; golf courses; sanitary landfills; sewage treatment plants; water control structures and spillways; other land used for such purposes; small parks (less than 10 acres) within urban and built-up areas; and highways, railroads, and other transportation facilities if they are surrounded by urban areas. Also included are tracts of less than 10 acres that do not meet the above definition but are completely surrounded by Urban and Built-up land. Two size categories are recognized in the NRI: (i) areas 0.25 to 10 acres, and (ii) areas greater than 10 acres. [NRI-97]


Product Information

Product ID: 5104
Production Date: 11/22/99
Product Type: Map


For additional information contact the Resources Inventory and Assessment Division. Please include the Product ID you are inquiring about. nri@wdc.usda.gov or 1400 Independence Avenue SW - P.O. Box 2890 - Washington D.C. 20013. If you use our analysis products, please be aware of our disclaimer.