3. Sédiment Transport
63
X = x/xt>, x — distance normal to the shoreline, Xb being the distance
from the shoreline to the breaker zone and V — proportionality coefficient
obtained with the inclusion of latéral mixing, needs to be multiplied with
ko to obtain the actual velocity.
The other parameters are given by
A = [1/(1 - 2.5P)]; (P + 0.4); B, = [(P2 - l)/(Pt - P2)]Æ
B2 = [(P, - l)/(Pi - P2)\A-,
Pi = (-3/4) + [(9/16) + (1/P£)]1/2; P2 = (-3/4) - [(9/16) + (1/Pe)]1'2
£ = 1/(1 -F 0.37572); P = (mnN/'yCf)
where. 7— is the wave breaking index (consider as H = 0.78
parameter "A'" varies between 0 and 0.016. Komar [1979] has combined
the above longshore current velocity distribution of Longuet-Higgins 1970]
with Bagnold [1966] and formulated the distribution of sédiment transport
along the surf zone due to waves and longshore current as
4 = K2[CfpV2 + 0.5/p(0.2572pd)]V
(3.38)
where, apart from the variables explained above, f — coefficient for oscillatory wave motion, V — local longshore current velocity, K2 — proportionality constant between available power and resulting sédiment transport.
This K2 is evaluated by integrating the above équation across the surf zone
gives the équation below,
Il = K2
\ $
A
Bi \
3 + Pi + 2 ) VqX2 tan a
„
(A3
3A2Bi
3AB%
2(Pi + 1)
Bf A
(3P1 + 1)/
(3.39)
V03W
where A, B\ and Pi are from longshore current distribution by LonguetHiggins (1970), ko — being the longshore current, in the absence of horizontal mixing, Xb — surf zone width and this Eq. (3.78) will be equated
to total transport rate given by Komar and solved for K2.
63
X = x/xt>, x — distance normal to the shoreline, Xb being the distance
from the shoreline to the breaker zone and V — proportionality coefficient
obtained with the inclusion of latéral mixing, needs to be multiplied with
ko to obtain the actual velocity.
The other parameters are given by
A = [1/(1 - 2.5P)]; (P + 0.4); B, = [(P2 - l)/(Pt - P2)]Æ
B2 = [(P, - l)/(Pi - P2)\A-,
Pi = (-3/4) + [(9/16) + (1/P£)]1/2; P2 = (-3/4) - [(9/16) + (1/Pe)]1'2
£ = 1/(1 -F 0.37572); P = (mnN/'yCf)
where. 7— is the wave breaking index (consider as H = 0.78
parameter "A'" varies between 0 and 0.016. Komar [1979] has combined
the above longshore current velocity distribution of Longuet-Higgins 1970]
with Bagnold [1966] and formulated the distribution of sédiment transport
along the surf zone due to waves and longshore current as
4 = K2[CfpV2 + 0.5/p(0.2572pd)]V
(3.38)
where, apart from the variables explained above, f — coefficient for oscillatory wave motion, V — local longshore current velocity, K2 — proportionality constant between available power and resulting sédiment transport.
This K2 is evaluated by integrating the above équation across the surf zone
gives the équation below,
Il = K2
\ $
A
Bi \
3 + Pi + 2 ) VqX2 tan a
„
(A3
3A2Bi
3AB%
2(Pi + 1)
Bf A
(3P1 + 1)/
(3.39)
V03W
where A, B\ and Pi are from longshore current distribution by LonguetHiggins (1970), ko — being the longshore current, in the absence of horizontal mixing, Xb — surf zone width and this Eq. (3.78) will be equated
to total transport rate given by Komar and solved for K2.