Drainage basin size and cultural characteristics of National Stream 
 Quality Accounting Network and Hydrologic Benchmark Network watersheds  

 [NASQAN, National Stream Quality Accounting Network; HBN, Hydrolgic
 Benchmark Network.  The drainage area statistics exclude 29 watersheds 
 with interderminant area.  The cultural characteristics were estimated 
 using digital drainage boundaries for 507 NASQAN stations.  Accounting 
 unit boundaries were used for 85 NASQAN stations without digitized 
 drainage basin boundaries.  Cultural characteristics are not available 
 for 26 stations located outside of the conterminous United States.  
 Population data are from 1990 (U.S. Bureau of Census, 1991), and 
 land-cover statistics are for 1987 (U.S. Soil Conservation Service, 
 1989).  Population and land-cover data are not reported for HBN 
 watersheds because their small size prevents accurate estimation 
 of these statistics.  Refer to the accompanying Open-File Report 
 96-337 for further details]

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 CHARACTERISTIC         RANGE              PERCENTILES OF STATION WATERSHEDS
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                 Minimum     Maximum        25th         50th          75th
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  NASQAN BASINS
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 Drainage area
    (mi2)            1     1,140,500       1,238        4,390         14,910
 Population
  density(#/mi2)   0.7         2,577        14.3         41.3          108.3
 Crop area (%)       0          90.4         4.5         12.4           29.3
 Forest area(%)      0          87.7         3.4         17.4           50.6
 Urban area(%)       0          43.3         0.7          2.0            4.5
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   HBN BASINS
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 Drainage area
    (mi2)            2         2,000          24           57             99
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