ERDC/CHL CETN-IV-28
September 2000
CLASS:
Horizontal Channel Expansion
SUBCLASS:
Expansion into Bay - Flood Tidal Shoal
Description: A flood shoal forms on the interior of a tidal inlet from the
sediment transported by the flood tide. Typically is either one large shoal, two
approximately symmetric shoals, or a bat-shaped shoal.
Processes: Flood-tidal current transports littoral material through the inlet.
Upon experiencing the calm waters of the interior, sediments accumulate. The
decrease in velocity is due to the horizontal spreading of the flood jet.
CASE EXAMPLE - 1
Site: Bakers Haulover, Dade County, Florida
Photographed 11/24/1975
Project: Intercoastal waterway (ICWW) crosses flood shoal
Authorized Channel Dimensions:
Depth; 10 ft-mlw
Bottom Width; 125 ft
Shoaling History: Unknown
Morang, A. (1999). Coastal Inlets Research Program, Shinnecock Inlet, New York, Site Investigation, Report 1, Morphology and
CASE EXAMPLE - 2
Historical Behavior, Technical Report CHL-98-32, US Army Engineer Research and Development Center, Vicksburg, MS.
Site: Shinnecock Inlet, Long Island, New York
Photographed 4/10/95
Project: Federal Navigation Project from the Atlantic Ocean through the inlet to the Long Island
Intracoastal Waterway (LIIW).
Atlantic Ocean through inlet
Inlet to Long Island Waterway (LIIW)
Authorized Channel Dimensions:
Depth; 10 ft-mlw
Depth; 6 ft-mlw
Width; 200 ft
Width; 100 ft
Shoaling History:
Total flood shoal volume (cu yd), including dredged channels directly north of barrier island
Inlet Opened by Hurricane
Sep 1938
Jul-Aug 1949
678,000
Nov 1955
638,000
Figure 1. Sample page from DMS Manual
2.0
Flood
1.5
1.0
0.5
0.0
-0.5
-1.0
-1.5
Ebb
-2.0
337.0
337.5
338.0
338.5
339.0
Julian Day 1998
Figure 2. Time series of current measured near center of Shinnecock
Inlet, NY, showing a strong tendency for flood dominance
4
Previous Page
