Evidence of Cross-Shore 

 Sediment Transport 



Introduction 



This chapter examines literature concerning evidences of cross-shore 

 transport of sediment on the inner shelf. Patterns and mechanisms of sedi- 

 ment transport on the inner shelf, particularly in the cross-shore dimen- 

 sion, and of beach-shelf sediment interchange are poorly understood 

 (Wright et al. 1991). Consequently, the generation of predictive theories 

 which address these mechanisms and effectively recreate their effect on 

 the cross-shore transport of sediment across the inner shelf is very diffi- 

 cult. Several authors (Wright 1987, Nummedal and Snedden 1987, Pilkey 

 et al. 1993) concur that a model directly relating cross-shore sediment 

 transport to transport mechanisms/processes is needed. 



Additional topics discussed in this chapter include surf zone and inner 

 shelf cross-shore transport of sediment, interchange of sediment between 

 the beach and the inner shelf, and if this interchange results in the loss of 

 sediment from the beach/inner shelf system to the outer shelf, storm/fair- 

 weather sediment transport and storm sedimentation models. The purpose 

 of the section concerning cross-shore sediment transport is not to provide 

 a comprehensive review of all the theories of cross-shore sediment trans- 

 port, but to discuss some of the evidences of this phenomenon and their re- 

 lation to the theories of cross-shore sediment transport on the inner shelf. 



Mechanisms of Inner Shelf Sediment Transport 



The research of Wright et al. (1991) showed that bidirectional cross- 

 shore sediment transport on the inner shelf is an exceedingly complex phe- 

 nomenon driven primarily by shoaling waves, wind- and tide-generated 

 currents, wave-current interactions, gravity-induced downslope transport, 

 mean flows, and geostrophic circulation. However, these mechanisms 

 have not been prioritized in terms of relative importance. 



Chapter 3 Evidence of Cross-Shore Sediment Transport 



19 



