Suspended Sediment Modeling of Dredge-Disposal Effluent in the GREAT-II Study Reach, 1980

The disposal of dredged material has recently received much attention. There is a need for mathematical models to predict the disposition of suspended solids resulting from disposal of dredged material. Much of the modeling on suspended solids plumes resulting from dredge disposal has been for open sea or estuarine operations. Little work has been done on dredge disposal in the river environment. The • objectives of this study were to: l) Collect field data on suspended solids and turbidity during two dredge disposal operations on the Mississippi River, 2) Check the utility of the Schubel and Carter (1978) model for adequately describing the observed field data and modify, if possible, to reflect river conditions, 3) Examine other models available to describe the observed field data, including the numerical, computer solution of Weschler and Cogley (1977) (such models can be used to rapidly generate a number of simulations covering a spectrum of conditions expected in the Mississippi River), and 4) Develop a convenient, analytical solution for the prediction of suspended solids concentrations caused by hydraulically dredged sediment and compare the model results to field measurements. The scope of this modeling effort includes the utilization of existing dredge disposal mathematical models, both analytical and numerical, as well as the development of a new model. The new model is specifically derived for continuous nonpoint source, sidebank disposal type of operations such as commonly practiced in the upper Mississippi River