One of a UK network of tide gauges maintained to the highest and most consistent standards.
Gain of material on the shore leading to increased levels, the growth of sand dunes on sandy shores and the expansion of marshes on muddy shores.
Layers of stone, concrete or other material to protect the toe of a structure such as a seawall.
Large quarried stone, or concrete block, used as protection against wave action.
Coastal area between the beach head and high water, potentially affected by large waves during high tides.
A sand or shingle bar above high tide, parallel to the coastline and separated from it by a lagoon.
A deposit of non-cohesive mobile material (e.g. sand, gravel) situated on the interface between dry land and the sea (or other expanses of water).
From the beach crest out to the limit of sediment movement.
Ridge, cliff, dune or sea defence forming the landward limit of the potentially active beach
Beach cross-section perpendicular to the shore, which may extend from the backshore, across the foreshore and into the nearshore zone.
Mechanical addition of imported sediment to a beach, also known as beach replenishment/nourishment.
Beach: near horizontal plateau above high water, formed by deposition of beach
material by wave action or by mechanical plant as part of a beach recharge
scheme. Structure: near horizontal area, often separating the upper part of a
seawall or revetment from the lower part.
Use of chemical glues to create a skin across a sediment surface. Usually applied
area within a dune system.
Bog Hole is the remnant of a former channel in the Ribble estuary inshore of
the Horse Bank. The bed of the Bog Hole was once many metres below low-water.
It has filled with sediment during the past two centuries and now its lowest
bed level is one metre below the height of the lowest neap tides.
rounded rock on a beach, greater than 250mm in diameter.
of the beach head or defence
flooding by tidal action.
zone within which waves approaching the coastline commence breaking,
typically in water depths of between 5 and
faced or steeply inclined structure built parallel to the shoreline, at or
near the crest of the beach, to resist erosion, usually timber.
coastal structure designed to protect an area from wave action, either for
navigation or coastal defence. Can be connected to or detached from the
beach material from the updrift to the downdrift side of an
obstruction to longshore drift i.e. harbour breakwater, estuary or
level to which both tidal levels and water depths are reduced - on most UK
charts this level is approximately the predicted lowest astronomical tide
or management operations intended to control coastal erosion
A division of the shoreline with
geographic limits set by the boundaries of natural physical processes,
usually coastal sediment movement. See Sediment cell
generic term embracing both “coast protection” which is the protection of
land from coast erosion and “sea defence” which is the protection of land
from flooding by the sea.
A coastal-cell partnership of coastal
defence operating authorities, environmental organisations, land owners and
conservation groups that shares knowledge and experience of shoreline
management issues and helps to define objectives for the future management of
term covering the action of natural forces on the shoreline, and nearshore
effect when hard defences (including beaches fixed in position by control
structures) interrupt the natural response of the shoreline to sea level
rise, restricting landward retreat and resulting in loss of the intertidal
interface between land and sea.
rounded rock on a beach, with diameter ranging from about 75 to 250mm - see also boulder,
containing significant proportion of clays, the electromagnetic properties of
which cause the sediment to bind together.
and/or animals living together under characteristic, recognisable conditions.
inner, often much less permeable portion of a breakwater, or barrier beach.
point on a beach face, breakwater or seawall.
to the shoreline.
of dunes by wind action.
an extreme wave condition with a specified return period used in the
design of coastal works.
without any constructed connection to the shore.
affecting wave propagation, by which wave energy is radiated normal to the
direction of wave propagation into the lee of an island or breakwater.
The spatial range of a
species, usually on a geographic but sometimes on a smaller scale, or the
arrangement or spatial pattern of a species over its habitat
mso-bidi-font-family:Arial;mso-ansi-language:EN-GB'>In community ecology, an
event that removes organisms and opens up space which can be colonised by
individuals of the same or different species
with greatest effect on shoreline processes.
to which material is being transported in the littoral zone.
of windblown sand on the backshore, usually in the form of small hills or
ridges, stabilised by vegetation or control structures.
seaward face of a dune system where coastal processes may cause erosion or
when tide level is falling; often taken to mean the ebb current that occurs
during this period.
Ebb tide delta
Area of sediment deposition caused by a decrease in
velocity of tidal currents where there is interaction with more open
nearshore conditions. Typically such deltas form at the mouths of estuaries
and restricted channels where they enter the sea
The study of the interactions of organisms with
their physical environment and with one another
All of the organisms of a given area and the
encompassing physical environment
bank protecting land from flooding.
Loss of material
from the shore leading to reduced levels and, in the absence of a hard line
of defence, landward recession of the coastline.
semi-enclosed coastal body of water within which seawater is measurably
diluted with fresh water derived from land drainage.
value expected to be exceeded once, on average, in a given (long) period of
over which a wind acts to produce waves - also termed fetch length.
in which wave energy (or wave height) is limited by the size of the wave
generation area (fetch).
with a surface stabilised by vegetation.
dune which lies nearest the sea in a prograding system, also embryo-dune.
Backshore area formed by
the deposition of sediment which is no longer part of an active coastal
between high and low water - see also intertidal.
height of the crest of a structure above the still water level.
mesh baskets filled with rock.
or natural fabrics used in engineering to separate layers of granular
material usually well rounded and between about 2mm and 75mm in diameter -
see also shingle.
fixed dune with mosses, lichens, grasses and herbs.
shore-normal (approximately) structure built to reduce longshore currents,
and/or to trap and retain beach material. Most groynes are of timber or rock,
and extend from the beach head across the foreshore.
beach compartment between two groynes.
recognisable area or type of environment in which an organism normally lives.
term applied to impermeable coastal defence structures of concrete, timber,
steel, masonry etc, which reflect a high proportion of incident wave energy.
cf. Soft defences
Hard feature (natural or
artificial) forming local limit of longshore extent of a beach.
The highest line
on the shore or at the coastline to which tides rise and advance landward.
The Horsebank is
a broad-crested bank of sand that appears on 19th and 20th
charts of the coast. Its crest, about
2 metres above the level of the adjoining shore, is roughly parallel to and
about 2 kilometres distant from the Southport coastline. The crest is covered by 85% of tides.
zone between high and low tide lines - see also foreshore.
probability of two (or more) events occurring together.
process by which percolating water removes nutrients from the soil
of beach material in the littoral zone under the influence of waves
from the beach head seawards to the limit of wave induced sediment
of (beach) sediments approximately parallel to the coastline.
The lowest line
on the shore to which tides fall and retreat seaward.
range greater than 4m.
The setting back of
existing coastal defences in order to achieve environmental, economic and/or
engineering benefits. Typically being undertaken in estuarine systems to
combat the issue of coastal squeeze
range between 2m and 4m.
range less than 2m.
The movement of
individuals and commonly whole populations from one area to another
area of fine silt usually exposed at low tide but covered at high tide,
occurring in sheltered estuaries or behind shingle bars or sand spits.
organic material into the sediment surface to reduce erosion, moisten the
surface and fertilise the soil.
process by which one community of organisms gives way to another in an
orderly series from colonisers to climax.
A tide of lower
range than an average (“ordinary”) tide due to the sun’s and moon’s
gravitational forces acting on the sea at an angle to each other.
where waves are transformed by interaction with the sea bed.
to the analysis or prediction of coastal processes using computational
zone beyond the nearshore zone where sediment motion induced by waves
alone effectively ceases and where the influence of the sea bed on wave
action has become small in comparison with the effect of wind.
The process where water
is carried over the top of an existing defence due to wave activity
effect of waves overtopping a beach, often carrying sediment landwards
to the investigation of coastal processes using a scaled model.
beach located between two headlands.
Any group of individuals,
usually of a single species, occupying a given area at the same time
of greatest frequency, often but not always the dominant winds.
along the shore or into open water.
succession of plants on sand especially dunes systems
ridge of rock, or other material, lying seawards of the low water line.
by which the direction of a wave moving in shallow water at an angle to the
bathymetric contours is changed so that the wave crests tend to become more
aligned with those contours.
mechanical movement of beach sediment from the lower foreshore to the upper
foreshore -see also reprofiling.
mechanical movement of beach sediment from downdrift to updrift - see also regrading.
period of time between occurrences of a given probability event.
on the seaward slope of a coastal embankment.
root.ball of plant from which roots and side shoots develop.
upper and lower levels reached by a wave on a beach or coastal structure,
relative to still. water level.
formation of beach material developed by wave refraction and diffraction and
longshore drift comprising a bulge in the coastline towards an offshore
island or breakwater, but not connected to it as in the case of a tombolo.
area having characteristic vegetation adapted to saline soils and to periodic
submergence in sea water.
particles, mainly of quartz, with a diameter of between 0.062mm and 2mm,
generally classified as fine, medium, coarse or very coarse
or management operations intended to prevent coastal flooding
Sea level rise
The general term given to the upward trend in mean
sea level resulting from a combination of local or regional geological
movements and global climate change
near vertical coastal defence structure built parallel to the coastline,
usually of concrete or masonry.
material of which a shore, riverbed or seabed is comprised. Sediment is moved on to, along and away
from the shore by wind, waves and currents.
It can be transported by air or water currents over the ground or
seabed or may be carried in suspension in air or water. Fine sediment (silt or mud) settles slowly
in low energy environments. Coarse
sediment (sand or gravel) settles quickly and is transported in higher energy
the context of a strategic approach to coastal management, a length of
coastline confined by natural or artificial barriers around which no sand or
shingle can be transported — also know as coastal cell.
or area at which beach material is irretrievably lost from a sediment cell,
such as an estuary, or a deep channel in the seabed.
or area on a coast from which beach material arises, such as an eroding
cliff, or river mouth.
grained beach sediment dominated by gravel but including some sand. Shoreline
One characteristic of the coast, often poorly defined, but essentially the
interface between land and sea.
Feature of the upper
beach, comprising built up deposits of shingle often fronting lower lying
between the high and low water marks of spring tides.
A zone that
encompasses near-shore coastal waters, the shore, the coastline and its
Shoreline Management Plan or SMP
SMPs have been
produced for the whole coastline of England and Wales with limits determined
by natural physical processes to enable operating authorities to identify
long-term sustainable policies for the coastal defence of the shoreline. Sefton has two of the SMPs: - Liverpool
Bay (Great Orme to Formby Point) and Ribble Estuary (Formby Point to the
as the average height of the highest third of the waves in a sea, and is
approximately height the visually observed wave height (H, or H).
shore parallel structure, submerged at high tide.
particles with a grain size between 0.004mm and 0.062mm i.e. coarser than
clay particles but finer than sand.
within dune system where the surface is at or near the ground water level.
refers to managed beaches, salt marshes or mudflats that provide protection to
the shoreline, but may also include rock structures which dissipate waves
rather than opposing them. cf. Hard defences
A tide of
greater range than an average (“ordinary”) tide due to the sun’s and moon’s
gravitational forces acting on the sea approximately in line with each
other. Spring and neap tides occur in
sequence following a lunar half-monthly cycle of approximately 15 days. There are also longer-term cycles that
vary according to astronomic circumstances.
long, narrow accumulation of sand or shingle, lying generally in line with
the coast, with one end attached to the land and the other protecting into
the sea or across the mouth of an estuary.
of debris formed at the limit of wave run up along the upper foreshore. Surge
Changes in water level as a result of meteorological forcing (wind, high or
low barometric pressure) causing a difference between the recorded water
level and that predicted using harmonic analysis; may be positive or
The orderly progression
of changes in a community composition that occurs during development of
vegetation in any area from initial colonisation to the attainment of the
climax typical of a particular geographic area
mode of sediment transport in which the particles are supported, and carried
along by water.
zone of wave action on the beach, which moves as water levels vary, extending
from the limit of run-down to the limit of run-up.
wind-generated waves. Swell characteristically exhibits a more regular and
longer period and has longer crests than locally generated waves - see also wind
zone of wave action extending from the water line (which varies with tide,
surge, set-up, etc.) out to the most seaward point of the zone (breaker zone)
at which waves approaching the coastline commence breaking, typically in
water depths of between 5 and 10
motion of water responding to changes in sea level during a tidal cycle
distance (height or amplitude) between sea level at low-water and sea level
at high-water during a single tide.
The maximum range of spring tides at Southport is approximately 10
metres and the minimum range of neap tides is approximately 4.5 metres.
movement of the sea caused by the gravitational attraction of sun and
moon. Each tidal cycle (from high-to
low-to high) takes approximately 12.5 hours.
formation of beach material developed by refraction, diffraction
and longshore drift to form a ‘neck’ connecting a coast to an offshore
island or breakwater - see also salient.
of brushwood laid down to protect dune grasses and help trap sand.
from which material is being transported in the littoral zone.
Plant communities on
shingle ranging from pioneer plant species on fringing shingle beaches
through to lichen-rich turf to gorse scrub on disturbed or marginal areas and
where grazed to a species-rich turf.
below which the soil is waterlogged.
seasonal and annual distribution of wave height, period and direction.
direction of wave energy propagation relative to true North.
distance from wave trough to crest.
taken for the passage of successive waves past a point.
of wave energy as a function of wave frequency and direction.
in wave energy due to the action of physical processes.
showing the long term distribution of wind speed and direction.
conditions directly attributed to recent winds - see also swell.
of the water level over an area directly caused by wind stress on the water
vegetated dune with bare sand frequently exposed between plan