Longshore Sediment Transport

1
(No Transcript)
2
Longshore Sediment Transport
Bedload or Suspended Load?
Komar (1978) BL 75 of L.T. Walton Chui
(1979) BL 9.4 (FV sin2bb/Hb0.5)
FV Fall Velocity bb Breaker Angle Hb
Breaker Height
3
(No Transcript)
4
(No Transcript)
5
(No Transcript)
6
(No Transcript)
7
(No Transcript)
8
CERC Formula
9
Volumetric Littoral Transport Rate as a
Function of Pls (US Army, 1977)
10
Comparison of Computer Longshore Sediment Drift
Rates for Five Second Waves
11
(No Transcript)
12
Project No. Hilton HD, 74.02.19, Plot No. 0,
Period 7.1 sec., Ray No. 11.
13
(No Transcript)
14
The long-shore power gradient on a cape/bay
sequence may be calculated if the wave height and
angle of wave approach at the shore is known or
can be determined from the bathymetry. The
derivative of the power gradient then gives a
sediment transport rate. A rapid increase in this
sediment transport rate at the cape leads to
erosion ,while a decrease at the bay leads to
deposition. The model allows these rates to be
calculated. (after May and Tanner, 1973)
15
Variations in Longshore Transport due to
Hurricane Gloria (1985), New Jersey Coast
16
(No Transcript)
17
(No Transcript)
18
Littoral Drift Rates Along Coasts (from
Johnson, 1956, 1957)
19
(No Transcript)
20
WAVENRG-predicted net longshore transport rates
computed using WIS and USN (composite) deep water
waves data and USN storm and fairweather inputs
(lower) from Grayton Beach to Morgan Peninsula.
21
Location and Bathymetric Map of the
Apalachicola-Panama City Coastal Area (Isobaths
in meters below Mean Lower Low Water).
22
Location and Bathymetric Map of the
Pensacola-Mobile Bay Area
(Isobaths in meters below Mean Lower Low Water).
23
Sediment Transport Model for the Grayton
Beach-Santa Rosa Island Region, and the Perdido
Key-Morgan Peninsula Region. Transport rates are
in m3yr-1.
24
(No Transcript)