on Coastal Engineering^ ASCE/ Capetown/ Nov 14-19^ 1982 



MODELING COASTAL CURRENTS AND SEDIMENT TRANSPORT 



by 



Y. Peter Sheng^ 



and 

 H. Lee Butler^ 



ABSTRACT 



An efficient three-dimensional model of coastal currents and 

 sediment transport has been developed. Simulations of tide- and 

 wind-driven currents and sediment transport in the Mississippi Sound 

 are presented. Results of a laboratory study on settling, 

 resuspension, and deposition of sediment are briefly described. Wave 

 effect on sediment resuspension is also addressed. 



INTRODUCTION 



Sediment transport in shallow coastal waters is an important 

 coastal engineering problem. Many coastal waters, e.g. the Mississippi 

 Sound, are receiving greater environmental concern due to increasing 

 utilization of their resources, including dredging of shipping channels 

 and disposal of dredged materials. To develop a regional plan of 

 dredged material disposal alternatives, one should not only be 

 concerned with the short-term fate of dredged material at specific 

 sites, but more importantly the subsequent resuspension, transport, and 

 deposition of sediment due to combined current and wave actions, 

 particularly during the sporadic high-energy events. 



The various physical processes that can affect the distribution of 

 sediment in a coastal environment are shown in Figure 1. Definitive 

 quantitative understanding of the various processes is crucial to the 

 success of any large-scale model. Recent improvements in numerical 

 estimation of currents and waves and the increased availability of 

 field data and satellite imageries has made it feasible to carry out 

 meaningful large-scale simulation studies of sediment transport events 

 (e.g. Sheng and Lick, 1979; Sheng, 1980). In this paper, we highlight 

 a systematic study of the sediment transport in the shallow coastal 

 waters of the Mississippi Sound and adjacent continental shelf waters 

 in the Gul f of Mexico. 



^Aeronautical Research Associates of Princeton, Inc., P.O. Box 2229, 

 Princeton, NJ 08540 U.S.A. 



Wave Dynamics Division, Hydraulics Laboratory, U.S. Army Engineer 

 Waterways Experiment Station, P.O. Box 631, Vicksburg, MS 39180 

 U.S.A. 



267 



