Sources, Instream Transport, and Trends of Nitrogen, Phosphorus, and Sediment in the Lower Tennessee River Basin, 1980-96

List of Figures

1-4. Maps showing:

1. Location of the lower Tennessee River Basin NAWQA study unit

2. Subunits, major hydrologic units, and location of selected monitoring sites and basin boundaries in the lower Tennessee River Basin

3. Land use and land cover, major hydrologic units, and location of selected monitoring sites and basin boundaries in the lower Tennessee River Basin

4. Location of wastewater dischargers and estimated wastewater input of total nitrogen and total phosphorus in the lower Tennessee River Basin in 1995

5. Graph showing basin characteristics of tributary sites in the lower Tennessee River Basin where instream loads were estimated

6. Diagram showing anthropogenic sources and fluxes of nitrogen within an agricultural watershed

7-18. Graphs showing:

7. Seasonal variation in nutrient concentrations and model estimate of seasonal pattern at selected sites in the lower Tennessee River Basin, 1980-96

8. Variation in total nitrite plus nitrate and total phosphorus concentrations with streamflow and model estimate of streamflow variation in concentration at selected sites in the lower Tennessee River Basin, 1980-96

9. Relation of median value of total nitrogen concentrations during low streamflow conditions and median value of total nitrogen load during low streamflow conditions to wastewater-discharge input to the watershed

10. Nutrient concentrations at selected sites on the Tennessee River, 1980-96, for total nitrogen, total nitrite plus nitrate, total ammonia, and total phosphorus

11. Nutrient concentrations at selected sites on the Duck River, 1980-96, for total nitrogen, total nitrite plus nitrate, total ammonia, and total phosphorus

12. Annual yield and flow-weighted mean concentration of total nitrogen, total nitrite plus nitrate, total ammonia, and total ammonia plus organic nitrogen at selected sites in the lower Tennessee River Basin

13. Annual yield and flow-weighted mean concentration of total phosphorus, dissolved orthophosphorus, and suspended sediment at selected sites in the lower Tennessee River Basin

14. Total nitrogen input and export at selected sites in the lower Tennessee River Basin

15. Total phosphorus input and export at selected sites in the lower Tennessee River Basin

16. Comparison of distribution of flow-weighted mean concentrations at lower Tennessee River Basin sites with national distribution

17. Monthly instream load of total nitrogen at Elk River near Prospect, Tennessee, water years 1990-92

18. Relation of total nitrogen export to the balance of land-phase inputs to agricultural land

19. Map showing trends of instream concentrations of nitrogen, phosphorus, and suspended sediment in the lower Tennessee River Basin

20. Graph showing temporal variation in nutrient concentrations during 1980-96 and model estimate of trend at selected sites in the lower Tennessee River Basin for total nitrogen, total nitrite plus nitrate, total ammonia, and total phosphorus

Tennessee home page