Sediment Transportation and Deposition Models for Mobile Bay, Alabama

The objective of this study is the application of hydrodynamic and material transport mathematical models for Mobile Bay in predicting sediment transport and deposition profiles within the bay system. Of particular importance are the seasonal variations of sediment distribution which are critically influenced by current patterns within the estuary. Both point and non-point sources of sediment will be included in the analysis. Results will be presented in two ways. The first or long-term variations in sediment distribution will be assessed by correlation with tidal cycle average velocities at various locations within the bay. Calculated distribution patterns will be compared with observed bathemetic data over the past century. The net effect of the construction of the Mobile ship channel on deposition patterns within the bay will also be evaluated. Secondly, short-term variations in sediment transport and deposition resulting from man-made and natural disturbances will be analysed using a sediment transport model. This model will include deposition, bulk fluid transport and resuspension characteristics and will be capable of predicting localized, short-term sediment patterns from maintenance dredging operations within the bay. Model trend results will be compared with field data collected during recent dredging activities and high altitude photographic data obtained for the bay area.