EM 1110-2-1100 (Change 1)
31 Jul 03
B
BACK BARRIER
Pertaining to the lagoon-marsh-tidal creek complex in the lee of a coastal barrier island, barrier spit, or baymouth
barrier.
BACKBEACH
See BACKSHORE.
BACKRUSH
The seaward return of the water following the uprush of the waves. For any given tide stage the point of farthest
return seaward of the backrush is known as the Limit of backrush or limit backwash.
BACKSHORE
That zone of the shore or beach lying between the foreshore and the coastline comprising the BERM or BERMS
and acted upon by waves only during severe storms, especially when combined with exceptionally high water. Also
BACKBEACH. (See Figure A-1)
BACKWASH
(1) See BACKRUSH. (2) Water or waves thrown back by an obstruction such as a ship, BREAKWATER, or cliff.
BACKWASH RIPPLES
Low amplitude ripple marks formed on fine sand beaches by the Backwash of the waves.
BACKWATER CURVE
The longitudinal profile of the water surface in an open channel where the depth of flow has been increased by an
obstruction as a weir or a dam across the channel, by increase in channel roughness, by decrease in channel width or by a
decrease of the bed gradient
BANK
(1) The rising ground bordering a lake, river, or sea; or of a river or channel, for which it is designated as right or
left as the observer is facing downstream. (2) An elevation of the sea floor or large area, located on a continental (or island)
shelf and over which the depth is relatively shallow but sufficient for safe surface navigation (e.g., Georges Bank); a group of
shoals. (3) In its secondary sense, used only with a qualifying word such as "sandbank," "gravelbank," or "spoil bank," a
shallow area consisting of shifting forms of silt, sand, mud, and gravel.
BAR
A submerged or emerged embankment of sand, gravel, or other unconsolidated material built on the sea floor in
shallow water by waves and currents. See BAYMOUTH BAR, CUSPATE BAR.
BARRIER BEACH
A bar essentially parallel to the shore, the crest of which is above normal high water level. Also called offshore
barrier and BARRIER ISLAND.
BARRIER FLAT
The flat area, often marshy and populated with low vegetation, on the bay or lagoon side of a barrier island
A-4
Appendix A Glossary of Coastal Terminology
Previous Page
