Table 8. Calibration results for the seven-parameter log-linear regression model of nutrient and sediment concentrations for selected sites in the lower Tennessee River Basin
[The numerical values of the coefficients β1-β6 are not shown; rather, the table entries indicate the time period spanned by the calibration data sets, which varied among sites and constituents; the colors of the numbers indicate the statistical significance and the sign (positive or negative) of the regression coefficients β1-β6 (see eq. 1); 1985-95, coefficient significant and positive; 1985-95, coefficient significant and negative; 1985-95, coefficient not significant; β1 significant and positive (negative) indicates that concentrations increase (decrease) with increasing streamflow; β3 significant and positive (negative) indicates an increasing (decreasing) temporal trend in concentration; β5 and β6 significant indicate that concentrations vary in a seasonal pattern, the patterns are illustrated at the bottom of the table; additional interpretation of the significance and sign of each coefficient is explained in the text; other regression statistics, such as coefficient of determination and standard error, are reported with load estimates in table 9; --, not estimated, and results not shown on fig. 19 because record during common period was insufficient; entries in italics are subject to larger error than the other entries, for various reasons (described in footnotes); R (riverine), tributary site at which streamflow is not regulated, or at which a major component of streamflow is not regulated; FR (flow regulated), site located in an impoundment or where streamflow is strongly influenced by an upstream impoundment; common period, the time span of the calibration data set used to obtain trend estimates for this common period is indicated in the table entries]
_____________________________________________________________________________________________________________________________________________ Common period Site β1 β5 β6 β3 identi- Surface-water station/site location (Logarithm β3 (Sine (Cosine ________ fication _________________________________________________ Site of (Decimal {2 * π {2 * π (Decimal (fig. 2) Number Name type streamflow) time) * time}) * time}) time) _____________________________________________________________________________________________________________________________________________ Total nitrogen as N 1 PR1038 Clarks River at Almo, Ky. R 1985-95 1985-95 1985-95 1985-95 1985-94 2 03604000 Buffalo River near Flat Woods, Tenn. R 1982-95 1982-95 1982-95 1982-95 1985-94 4 001025 Duck River below Normandy Dam, Tenn. FR 1986-95 1986-95 1986-95 1986-95 -- 5 001065 Duck River at Williamsport, Tenn. R 1982-94 1982-94 1982-94 1982-94 1982-94 6 475793 Duck River above Hurricane Mills, Tenn. R 1986-93 1986-93 1986-93 1986-93 1985-94 7 002395 Shoal Creek at Highway 43 near R 1983-92 1983-92 1983-92 1983-92 -- Lawrenceburg, Tenn. a 9 001207 Elk River below Tims Ford Dam, Tenn. FR 1984-94 1984-94 1984-94 1984-94 1985-94 10 475796 Elk River near Prospect, Tenn. R 1987-92 1987-92 1987-92 1987-92 -- 11 FLCR7 Flint Creek near Falkville, Ala. R 1993-97 1993-97 1993-97 1993-97 -- 12 TOWNCREEK15 Town Creek near Geraldine, Ala. R 1988-96 1988-96 1988-96 1988-96 -- 13 002375 Sequatchie River at Valley Road, Tenn. a R 1983-95 1983-95 1983-95 1983-95 1985-94 14 03609750 Tennessee River at Highway 60 near FR 1980-84 1980-84 1980-84 1980-84 -- Paducah, Ky. 15 202832 Tennessee River at mile 23, Ky. b FR 1990-94 1990-94 1990-94 1990-94 -- 16 03593005 Tennessee River at Pickwick Landing Dam, FR 1980-96 1980-96 1980-96 1980-96 1985-94 Tenn. 17 03571850 Tennessee River at South Pittsburg, Tenn. FR 1980-85 1980-85 1980-85 1980-85 -- 18 003315 Tennessee River below Raccoon Mountain, FR 1981-94 1981-94 1981-94 1981-94 1985-94 Tenn. Total ammonia as N 1 PRI038 Clarks River at Almo, Ky. R 1985-95 1985-95 1985-95 1985-95 1986-94 2 03604000 Buffalo River near Flat Woods, Tenn. R 1987-92 1987-92 1987-92 1987-92 -- 4 001025 Duck River below Normandy Dam, Tenn. FR 1987-95 1987-95 1987-95 1987-95 -- 5 001065 Duck River at Williamsport, Tenn. R 1984-94 1984-94 1984-94 1984-94 1986-94 6 475793 Duck River above Hurricane Mills, Tenn. R 1987-94 1987-94 1987-94 1987-94 -- 7 002395 Shoal Creek at Highway 43 R 1984-94 1984-94 1984-94 1984-94 1986-94 near Lawrenceburg, Tenn. a 9 001207 Elk River below Tims Ford Dam, Tenn. FR 1984-94 1984-94 1984-94 1984-94 1986-94 10 475796 Elk River near Prospect, Tenn. R 1987-94 1987-94 1987-94 1987-94 -- 11 FLCR7 Flint Creek near Falkville, Ala. R 1993-97 1993-97 1993-97 1993-97 -- 12 TOWNCREEK15 Town Creek near Geraldine, Ala. c R 1988-96 1988-96 1988-96 1988-96 -- 13 002375 Sequatchie River at Valley Road, Tenn. a R 1983-95 1983-95 1983-95 1983-95 1986-94 15 202832 Tennessee River at mile 23, Ky. b FR 1990-94 1990-94 1990-94 1990-94 -- 16 03593005 Tennessee River at Pickwick Landing Dam, FR 1980-96 1980-96 1980-96 1980-96 -- Tenn. 17 03571850 Tennessee River at South Pittsburg, Tenn. FR 1980-86 1980-86 1980-86 1980-86 -- 19 SCARHAM- Scarham Creek near Kilpatrick, Ala. R 1988-96 1988-96 1988-96 1988-96 -- CREEK03 Total ammonia plus organic nitrogen as N 1 PRI038 Clarks River at Almo, Ky. R 1985-95 1985-95 1985-95 1985-95 1986-93 2 03604000 Buffalo River near Flat Woods, Tenn. R 1982-95 1982-95 1982-95 1982-95 1986-93 4 001025 Duck River below Normandy Dam, Tenn. FR 1986-95 1986-95 1986-95 1986-95 -- 5 001065 Duck River at Williamsport, Tenn. R 1981-92 1981-92 1981-92 1981-92 1986-93 6 475793 Duck River above Hurricane Mills, Tenn. R 1986-93 1986-93 1986-93 1986-93 1986-93 7 002395 Shoal Creek at Highway 43, R 1983-94 1983-94 1983-94 1983-94 1986-93 near Lawrenceburg, Tenn. a 9 001207 Elk River below Tims Ford Dam, Tenn. FR 1984-94 1984-94 1984-94 1984-94 1986-93 10 475796 Elk River near Prospect, Tenn. R 1986-93 1986-93 1986-93 1986-93 1986-93 11 FLCR7 Flint Creek near Falkville, Ala. R 1993-97 1993-97 1993-97 1993-97 -- 12 TOWNCREEK15 Town Creek near Geraldine, Ala. R 1988-96 1988-96 1988-96 1988-96 -- 13 002375 Sequatchie River at Valley Road, Tenn. a R 1983-95 1983-95 1983-95 1983-95 1986-93 14 03609750 Tennessee River at Highway 60 near FR 1980-84 1980-84 1980-84 1980-84 -- Paducah, Ky. 15 202832 Tennessee River at mile 23, Ky. b FR 1990-94 1990-94 1990-94 1990-94 -- 16 03593005 Tennessee River at Pickwick Landing Dam, FR 1986-93 1986-93 1986-93 1986-93 1986-93 Tenn. 17 03571850 Tennessee River at South Pittsburg, Tenn. FR 1980-85 1980-85 1980-85 1980-85 -- 18 003315 Tennessee River below Raccoon Mountain, FR 1981-94 1981-94 1981-94 1981-94 1986-93 Tenn. 19 SCARHAM- Scarham Creek near Kilpatrick, Ala. R 1988-96 1988-96 1988-96 1988-96 -- CREEK03 Total nitrite plus nitrate as N 1 PRI038 Clarks River at Almo, Ky. R 1985-95 1985-95 1985-95 1985-95 1985-94 2 03604000 Buffalo River near Flat Woods, Tenn. R 1986-93 1986-93 1986-93 1986-93 1985-94 4 001025 Duck River below Normandy Dam, Tenn. FR 1987-95 1987-95 1987-95 1987-95 -- 5 001065 Duck River at Williamsport, Tenn. R 1982-93 1982-93 1982-93 1982-93 -- 6 475793 Duck River above Hurricane Mills, Tenn. R 1987-93 1987-93 1987-93 1987-93 -- 7 002395 Shoal Creek at Highway 43, Tenn. a R 1983-94 1983-94 1983-94 1983-94 1985-94 9 001207 Elk River below Tims Ford Dam FR 1984-94 1984-94 1984-94 1984-94 1985-94 10 475796 Elk River near Prospect, Tenn. R 1987-93 1987-93 1987-93 1987-93 -- 11 FLCR7 Flint Creek near Falkville, Ala. R 1993-97 1993-97 1993-97 1993-97 -- 12 TOWNCREEK15 Town Creek near Geraldine, Ala. R 1988-96 1988-96 1988-96 1988-96 -- 13 002375 Sequatchie River at Valley Road, Tenn. a R 1983-95 1983-95 1983-95 1983-95 1985-94 14 03609750 Tennessee River at Highway 60 near FR 1980-84 1980-84 1980-84 1980-84 -- Paducah, Ky. 15 202832 Tennessee River at mile 23, Ky. b FR 1990-94 1990-94 1990-94 1990-94 -- 16 03593005 Tennessee River at Pickwick Landing Dam, FR 1980-96 1980-96 1980-96 1980-96 1985-94 Tenn. 17 03571850 Tennessee River at South Pittsburg, Tenn. FR 1980-85 1980-85 1980-85 1980-85 -- 18 003315 Tennessee River below Raccoon Mountain, FR 1981-94 1981-94 1981-94 1981-94 1985-94 Tenn. 19 SCARHAM- Scarham Creek near Kilpatrick, Ala. R 1988-96 1988-96 1988-96 1988-96 -- CREEK03 20 SOUTH- South Sauty Creek, Ala. R 1988-96 1988-96 1988-96 1988-96 -- SAUTYCK03 Total phosphorus as P 1 PRI038 Clarks River at Almo, Ky. R 1985-95 1985-95 1985-95 1985-95 1985-93 2 03604000 Buffalo River near Flat Woods, Tenn. R 1983-95 1983-95 1983-95 1983-95 1985-93 4 001025 Duck River below Normandy Dam, Tenn. FR 1987-94 1987-94 1987-94 1987-94 -- 5 001065 Duck River at Williamsport, Tenn. R 1981-93 1981-93 1981-93 1981-93 1985-93 6 475793 Duck River above Hurricane Mills, Tenn. R 1988-93 1988-93 1988-93 1988-93 -- 7 002395 Shoal Creek at Highway 43 near R 1983-94 1983-94 1983-94 1983-94 1985-93 Lawrenceburg, Tenn. a 9 001207 Elk River below Tims Ford Dam, Tenn. FR 1983-94 1983-94 1983-94 1983-94 1985-93 10 475796 Elk River near Prospect, Tenn. R 1986-94 1986-94 1986-94 1986-94 -- 14 03609750 Tennessee River at Highway 60 near FR 1980-84 1980-84 1980-84 1980-84 -- Paducah, Ky. 15 202832 Tennessee River at mile 23, Ky. b FR 1990-94 1990-94 1990-94 1990-94 -- 16 03593005 Tennessee River at Pickwick Landing Dam, FR 1980-93 1980-93 1980-93 1980-93 1985-93 Tenn. 17 03571850 Tennessee River at South Pittsburg, Tenn. FR 1980-86 1980-86 1980-86 1980-86 -- Dissolved orthophosphorus as P 2 03604000 Buffalo River near Flat Woods, Tenn. R 1984-95 1984-95 1984-95 1984-95 -- 6 475793 Duck River above Hurricane Mills, Tenn. R 1986-91 1986-91 1986-91 1986-91 -- 10 475796 Elk River near Prospect, Tenn. R 1987-91 1987-91 1987-91 1987-91 -- 11 FLCR7 Flint Creek near Falkville, Ala. c R 1993-97 1993-97 1993-97 1993-97 -- 12 TOWNCREEK15 Town Creek near Geraldine, Ala. c R 1988-96 1988-96 1988-96 1988-96 -- 16 03593005 Tennessee River at Pickwick Landing Dam, FR 1983-93 1983-93 1983-93 1983-93 -- Tenn. 15 202832 Tennessee River at mile 23, Ky. b FR 1990-94 1990-94 1990-94 1990-94 -- 19 SCARHAM- Scarham Creek near Kilpatrick, Ala. R 1988-96 1988-96 1988-96 1988-96 -- CREEK03 Suspended sediment 2 03604000 Buffalo River near Flat Woods, Tenn. R 1982-95 1982-95 1982-95 1982-95 -- 3 03596000 Duck River below Manchester, Tenn. d R 1979-83 1979-83 1979-83 1979-83 -- 8 03588500 Shoal Creek at Iron City, Tenn. d R 1979-83 1979-83 1979-83 1979-83 -- 16 03593005 Tennessee River at Pickwick Landing Dam, FR 1980-93 1980-93 1980-93 1980-93 -- Tenn. 17 03571850 Tennessee River at South Pittsburg, Tenn. FR 1980-86 1980-86 1980-86 1980-86 -- _____________________________________________________________________________________________________________________________________________ a Regression results are subject to error because streamflow-measurement and water-quality-sampling sites were not colocated. b Regression results are subject to error due to grab sampling methods at this vertically stratified site. c Regression results are subject to error due to variable minimum reporting level and large percentage of observations below minimum reporting level. d The calibration data set included data from 1979 in order to have sufficient length of record.
Seasonal patterns: Printable version of this figure also available as a PDF
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