Conclusions 1 II. Nutrient Loadings 10 V. Literature Reviewed 15 VI. A generalized representation or model relating sources, concentrations, and impacts can be constructed.
By applying measurements of relevant parameters associated with lake degradation, the generalized model can be transformed into an operational representation of a lake, its drainage basin, and related nutrients. With such a transformation, an assessment of the potential for eutrophication control can be made. Likewise, multivariate evaluations for the relationships between land use, nutrient export, and trophic condition, by lake class or use, are being developed to assist in the formulation of planning guidelines and policies by EPA and to augment plans implementation by the states.
Environmental Protection Agency expresses sincere appreciation to the North Carolina Department of Natural and Economic Resources for professional involvement and to the North Carolina National Guard for conducting the tributary sampling phase of the Survey. Lewis R. Taylor, Supervisor of the Monitoring Program Unit; provided invaluable lake documentation and counsel during the Survey, reviewed the preliminary reports, and provided critiques most useful in the preparation of this Working Paper series.
Major General William M. Bouchard, who directed the volunteer efforts of the North Carolina National Guardsmen, are also gratefully acknowledged for their assistance to the Survey. Trophic Condition: Survey data indicate that Lake Hickory is eutrophic. However, since the mean hydraulic retention time of the lake is a rather short 33 days, it more closely resembles a slow-moving river; and the term "over-enriched" may be a more appropriate description of the condition of the lake.
Depression of dissolved oxygen with depth occurred at all four sampling stations in July and September. Survey limnologists noted that the water was turbid on all sampling occasions. No algal blooms were observed, although phytoplankton numbers in September indicate a near-bloom condition, and blue-green genera were dominant.
