Glossary
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Littoral Drift : The sedimentary material moved along the shoreline under the
influence of waves and currents.
Littoral Material : Sediment moved in the LITTORAL ZONE by waves and
currents. Also called littoral drift.
Littoral Transport : The movement of littoral drift along the shoreline by waves
and currents. Includes movement parallel (longshore transport) and
perpendicular (on-offshore transport) to the shore.
Littoral Zone : Indefinite (unprecisely defined) zone extending from the
shoreline to just beyond the breaker zone.
Longshore : Parallel to and near the shoreline : same as ALONGSHORE.
Longshore Transport Rate : Rate of transport of littoral material parallel to
shore. Usually expressed in cubic yards per year.
Low Tide : Minimum elevation reached by each falling tide.
Low Water Line : Intersection of the low tide level with shore.
Marsh : An area of soft, wet or periodically submerged land, generally treeless
and usually characterized by grasses and other low vegetation.
Mean High Water (MHW) : Average height of the daily high waters over a 19year period. For semidiumal or mixed tides, the two high waters of each tidal
day are included in the mean. For diurnal tides, the single daily high water is
used to compute the mean.
Mean Higher High Water (MHHW) : Average height of the daily higher high
water over a 19-year period. Only the higher high water of each of the high
waters of a tidal day is included in the mean.
Mean Low Water (MLW) : Average height ~ff the low waters over a 19-year
period. For semidiumal and mixed tides, the tow low waters of each tidal day
are included in the mean. For a diurnal tide, the one low water of each tidal
day is used in the mean. Mean Low Water has been used as datum for many
navigation charts published by the U.S. National Ocean Survey, but it is
being phased out in favor of Mean Lower Low Water for all areas of the
United States.
327
Littoral Drift : The sedimentary material moved along the shoreline under the
influence of waves and currents.
Littoral Material : Sediment moved in the LITTORAL ZONE by waves and
currents. Also called littoral drift.
Littoral Transport : The movement of littoral drift along the shoreline by waves
and currents. Includes movement parallel (longshore transport) and
perpendicular (on-offshore transport) to the shore.
Littoral Zone : Indefinite (unprecisely defined) zone extending from the
shoreline to just beyond the breaker zone.
Longshore : Parallel to and near the shoreline : same as ALONGSHORE.
Longshore Transport Rate : Rate of transport of littoral material parallel to
shore. Usually expressed in cubic yards per year.
Low Tide : Minimum elevation reached by each falling tide.
Low Water Line : Intersection of the low tide level with shore.
Marsh : An area of soft, wet or periodically submerged land, generally treeless
and usually characterized by grasses and other low vegetation.
Mean High Water (MHW) : Average height of the daily high waters over a 19year period. For semidiumal or mixed tides, the two high waters of each tidal
day are included in the mean. For diurnal tides, the single daily high water is
used to compute the mean.
Mean Higher High Water (MHHW) : Average height of the daily higher high
water over a 19-year period. Only the higher high water of each of the high
waters of a tidal day is included in the mean.
Mean Low Water (MLW) : Average height ~ff the low waters over a 19-year
period. For semidiumal and mixed tides, the tow low waters of each tidal day
are included in the mean. For a diurnal tide, the one low water of each tidal
day is used in the mean. Mean Low Water has been used as datum for many
navigation charts published by the U.S. National Ocean Survey, but it is
being phased out in favor of Mean Lower Low Water for all areas of the
United States.