Environmental and Water Quality Operational Studies. Analysis and Revision of a Reservoir Water Quality Model

• Main Authors: Wlosinski,Joseph H, Collins,Carol D
• Format: Report
• Language: English
• Subjects: ALGAE; ALGORITHMS; ALKALINITY; AMMONIA; ARKANSAS; CALIBRATION; CARBON; CE-QUAL-R1 computer program; Civil Engineering; CONSERVATION; Degray Lake; DISSOLVING; GRAPHICS; INORGANIC MATERIALS; MASS; MOUNTAINS; MULTIPURPOSE; NITROGEN; ONE DIMENSIONAL; ORGANIC MATERIALS; OXYGEN; PREDICTIONS; RESERVOIRS; SOLIDS; STABILITY; STATISTICAL TESTS; VARIABLES; WATER QUALITY; ZOOPLANKTON

CE-QUAL-R1 is a one-dimensional model being developed by the Corps of Engineers to predict and assess the effects of engineering activities on reservoir water quality. Evaluation consisted of tests of the code and comparisons of model predictions with field measured values. Tests of the code included evaluations of the stability of predictions, conservation of mass, time step comparisons, entries of initial values, use of different driving variables, and a check of equation dimensionality. Evaluations of model predictions were made using data collected in 1979 and 1980 at DeGray Lake, a Corps of Engineers multipurpose project located in the Ouachita Mountains in south-central Arkansas. Calibration data were collected in 1979, and confirmation data in 1980. Both graphical and statistical tests were used for comparing model predictions with measured values. Variables used in this study were: algae, zooplankton, dissolved organic matter, orthophosphate-phosphorus, ammonia nitrogen, nitrite plus nitrate nitrogen, inorganic carbon, oxygen, pH, alkalinity, and dissolved solids. This report includes an evaluation of different variables, processes, and algorithms that were changed in order to provide a model whose predictions more closely fit measured values.