Morphology Change Analysis

EMCM8_Shinnecock
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Bar

Bar

an equilibrium inlet and the cross sectional area of the throat (LeConte 1905; O'Brien

1931, 1969; Jarrett 1976). The empirical equation is,

Ac = CP n

(1)

where Ac is the channel cross-sectional area, P is the tidal prism, and C and n are

empirical coefficients. Values of C and n depend on the number of jetties present at

the inlet and the general wave climate. For Shinnecock Inlet the coefficients C and n

are 5.77 x 10-5 and 0.95 respectively. Application of the Jarrett (1976) equation to

Shinnecock Inlet using the 1998 estimate of tidal prism indicates the minimum cross-

sectional area in the throat of the inlet should approach 2,177 m2 (Buonaiuto 2003b).

A previous estimate gave a minimum inlet cross-sectional area of 2,694 m2 (Militello

and Kraus 2001). These empirically-estimated minimum cross-sectional areas are

larger than those measured in 1994 (1,551 m2) and 1998 (1,566 m2) (Morang 1999).

Between 1994 and 1998 the cross-sectional area of the channel increased, indicating

that the inlet was scouring toward the predicted equilibrium flow area.

The dominant direction of longshore transport along the south shore of Long

Island is from east to west (Taney 1961; Panuzio 1968). Seasonal winds from the

west and southwest in summer can induce short-term transport reversals along the