at *x*=*x*g, the ratio *p *of the total sediment transport that bypasses the groin is,

-1

∞ 1 *d *ξ 2

2

∞

1 *d*ξ

∫

(14)

0

where ξ = ratio of breaking waves given by ξ = exp ( -(γ b h / *H * x )2 ) , in which *H*x = local

root-mean-square (rms) wave height neglecting wave breaking.

dimensional parameters and the incident wave angle, namely: *x*g/*H*rms,o, *H*rms,o/*L*o, *A*/*H*rms,o1/3

Fig. 3 illustrates how the bypass ratio depends on normalized groin length and deepwater

wave steepness for a fixed value on *A*/*H*rms,o1/3.

Fig.3. Bypass ratio as a function of normalized groin length and deepwater wave steepness for

Cascade includes the Reservoir Model (Kraus 2000) to describe inlet sediment storage

and transfer. The inlet is schematized into distinct morphological units (ebb shoal proper,

bypassing bars, and attachment bars) and formulated relationships for how the sediment

moves between them. Sediment that approaches the inlet and bypasses the jetty is

transported to the ebb shoal. From the ebb shoal, the material is transferred to the

bypassing bar and then further downdrift to the attachment bar. From the attachment bar

the sediment is transported along the shore. Each morphological unit is assumed to have a

certain equilibrium volume for fixed hydrodynamic and sediment conditions. As the

volumes approach equilibrium values, more sediment is transferred downdrift. Kraus

(2000) assumed that the sediment passing through each unit is proportional to the ratio

between the actual volume and the equilibrium volume for the unit. If equilibrium is

Larson, Kraus, and Hanson

7