| Abstract: | Digital data sets were compiled by the U. S. Geological Survey (USGS) and used as input for a collection of Spatially Referenced Regressions On Watershed attributes for the Chesapeake Bay region. These regressions relate streamwater loads to nutrient sources and the factors that affect the transport of these nutrients throughout the watershed. A digital segmented network based on watershed boundaries serves as the primary foundation for spatially referencing total nitrogen and total phosphorus source and land-surface characteristic data sets within a Geographic Information System. Digital data sets of atmospheric wet deposition of nitrate, point-source discharge locations, land cover, and agricultural sources such as fertilizer and manure were created and compiled from numerous sources and represent nitrogen and phosphorus inputs. Some land-surface characteristics representing factors that affect the transport of nutrients include land use, land cover, average annual precipitation and temperature, slope, and soil permeability. Nutrient input and land-surface characteristic data sets merged with the segmented watershed network provide the spatial detail by watershed segment required by the models. Nutrient stream loads were estimated for total nitrogen, total phosphorus, nitrate/nitrite, amonium, phosphate, and total suspended soilds at as many as 109 sites within the Chesapeake Bay watershed. The total nitrogen and total phosphorus load estimates are the dependent variables for the regressions and were used for model calibration. Other nutrient-load estimates may be used for calibration in future applications of the models. |
| Genre: | USGS Numbered Series |
| ProdID: | 32201 |
| Citation Author: | Brakebill, John W.; Preston, Stephen D. |
| Citation Contributing Office: | Maryland Water Science Center |
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| Citation Edition: | Version 1.0 |
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| Citation Language: | ENGLISH |
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| Citation No Pagination: | Y |
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| Citation Online Only Flag: | Y |
| Citation Phsyical Description: | Unpaginated |
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| Citation Public Comments: | See OFR 2001-251 for version 2.0; see OFR 2004-1433 for version 3.0 |
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| Citation Series: | Open-File Report |
| Citation Series Code: | OFR |
| Citation Series Number: | 99-60 |
| Citation Search Results Text: | Digital data used to relate nutrient inputs to water quality in the Chesapeake Bay watershed; 1999; OFR; 99-60; Brakebill, John W.; Preston, Stephen D. |
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| Citation Year: | 1999 |
| Type: | citation/reference |
| Text: | Digital data used to relate nutrient inputs to water quality in the Chesapeake Bay watershed; 1999; OFR; 99-60; Brakebill, John W.; Preston, Stephen D. |
| URL (THUMBNAIL): | http://pubs.er.usgs.gov/thumbnails/usgs_thumb.jpg |
| URL (INDEX PAGE): | http://md.water.usgs.gov/publications/ofr-99-60/ |
| Date Other: | Wed, 1 Sep 1999 00:00 -0500 |
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