Physical Sciences and Mathematics Commons^™

Nearshore And Surf-Zone Morphodynamics: A Global Environmental Model For Predicting Hazards And Changes. Appendix 6. Standing Waves On A Pronounced Bar Trough Beach, Nungjane C. Shi, L. D. Wright

Reports

The hypothesis that a pronounced bar-trough surf zone topography favors resonance of standing waves with antinodes located over the bar is examined. Numerical and field investigations of standing waves in a bar-trough surf zone suggest a selective trapping of wave energy at specific resonant frequencies in the subharmonic and the high frequency infragravity bands and a possible suppression of lower frequencies. The resonant frequencies predicted by the numerical model remain fairly constant throughtout the tidal cycle due to the small tidal range typically associated with a bar-trough beach. Cross-shore bar migration changes the resonant frequencies. Numerical simulations show that an …

Nearshore And Surf-Zone Morphodynamics : A Global Environmental Model For Predicting Hazards And Changes, L. D. Wright, N. C. Shi, John D. Boon

Reports

The long-term goal of the project has been to develop improved, accurate predictability of nearshore, surf zone, and beach hydrodynamic and morphologic assemblages, based on lucidation of the universal principles governing nearshore and surf zone morphodynamic behavior.

Operation Manual For The Vims Combined Hydrodynamic-Ecosystem Model (Hem), Virginia Institute Of Marine Science

Reports

Since about 1970, VIMS has been developing water quality simulation models for the Virginia State Water Control Board under the Cooperative State Agencies (CSA) agreement. Under this agreement, VIMS has conducted field programs and developed and validated a number of water quality models. In order to make this accumulated experience available to the State Water Control Board and others, VIMS has prepared a users' manual and sample cases for the combined hydrodynamic-ecosystem model (HEM).

Effect Of Temperature And Dissolved Oxygen On Sediment-Water Nutrient Flux, C. F. Cerco

Reports

A series of experiments was conducted in order to determine the influence of water-column temperature and dissolved oxygen on sediment-water nutrient flux. Three nutrients were considered: ammoniurn nitrogen, nitrate nitrogen, and ortho phosphorus. Results of the experiments indicated that nutrient concentration in the overlying water had to be considered, as well as temperature and dissolved oxygen, as an independent variable which affected sediment-water nutrient flux.

Sediment-Water Column Exchanges Of Nutrients And Oxygen In The Tidal James And Appomattox Rivers, Carl F. Cerco

Reports

Fluxes between the sediments and overlying water of ammonium, nitrate, total phosphorus, ortho phosphorus, and dissolved oxygen have been measured in the tidal James and Appomattox Rivers, Va. A total of 68 nutrient flux measures, 203 oxygen flux measures, and 18 control measures were collected in the summer months, 1983 and 1984.

Ammonium is predominantly released from the sediments at a mean rate of 9.82 mg/m /hr. Nitrate is predominantly taken up by the sediments at a mean rate of 1.53 mg/m /hr. Total phosphorus is taken up by the sediments at a mean rate of 1.67 mg/m /hr. Ortho …