Trophic status evaluation of TVA reservoirs
TVA tributary and mainstem reservoirs show generalized differences in morphometry, hydraulics, nutrient loads, and response to nutrient concentrations. Neither type of reservoir is strictly comparable to the natural lakes on which classical eutrophication studies have been based. The majority of published trophic state indices and standards (e.g., hypolimnetic dissolved oxygen depletion, Secchi depth, areas nutrient loading rates, in-reservoir phosphorus concentrations) are inappropriate for evaluation of some or all TVA reservoirs. No single trophic potential or trophic response variable summarizes the mechanisms and manifestations of eutrophication sufficiently to be used as a sole criterion for judging or regulating TVA reservoir water quality. Relative multivariate trophic state indices were developed for mainstem and tributary reservoirs. Ranking of the mainstem reservoirs is based on chlorophyll, macrophyte coverage, hydraulic retention time, reservoir area less than five feet deep, annual pool elevation drawdown, and Secchi depth. Based on available data, the rank from least eutrophic to most eutrophic is: Pickwick, Kentucky, Chickamauga, Nickajack, Wilson, Fort Loudoun, Watts Bar, Wheeler, and Guntersville Reservoirs. Ranking of the tributary reservoirs is based on chlorophyll, total phosphorus and total nitrogen weighted by the N:P ratio, and bio-available inorganic carbon levels. The rank from least eutrophic to most eutrophic is: Hiwassee, Blue Ridge, Chatuge, Norris and Fontana, Watauga, South Holston, Tims Ford, Cherokee, Douglas, and Boone Reservoirs. 130 references, 18 figures, 30 tables.
- Research Organization:
- Tennessee Valley Authority, Chattanooga (USA). Div. of Water Resources
- OSTI ID:
- 5478299
- Report Number(s):
- TVA/ONR/WR-83/7; ON: DE84900364
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
Aquatic-- Site Resource & Use Studies-- (-1989)
54 ENVIRONMENTAL SCIENCES
AQUATIC ORGANISMS
DATA
DATA COMPILATION
DISSOLVED GASES
ENVIRONMENTAL QUALITY
EUTROPHICATION
FLUIDS
GASES
INFORMATION
NATIONAL ORGANIZATIONS
NUMERICAL DATA
NUTRIENTS
PLANKTON
PLANTS
PRODUCTIVITY
SOLUTES
SURFACE WATERS
TENNESSEE VALLEY AUTHORITY
TENNESSEE VALLEY REGION
US ORGANIZATIONS
WATER QUALITY
WATER RESERVOIRS