
Coastal engineering is a branch of
civil engineering
Civil engineering is a regulation and licensure in engineering, professional engineering discipline that deals with the design, construction, and maintenance of the physical and naturally built environment, including public works such as roads ...
concerned with the specific demands posed by constructing at or near the
coast
A coast (coastline, shoreline, seashore) is the land next to the sea or the line that forms the boundary between the land and the ocean or a lake. Coasts are influenced by the topography of the surrounding landscape and by aquatic erosion, su ...
, as well as the development of the coast itself.
The
hydrodynamic
In physics, physical chemistry and engineering, fluid dynamics is a subdiscipline of fluid mechanics that describes the flow of fluids – liquids and gases. It has several subdisciplines, including (the study of air and other gases in moti ...
impact of especially
waves
United States Naval Reserve (Women's Reserve), better known as the WAVES (for Women Accepted for Volunteer Emergency Service), was the women's branch of the United States Naval Reserve during World War II. It was established on July 21, 1942, ...
,
tide
Tides are the rise and fall of sea levels caused by the combined effects of the gravitational forces exerted by the Moon (and to a much lesser extent, the Sun) and are also caused by the Earth and Moon orbiting one another.
Tide tables ...
s,
storm surge
A storm surge, storm flood, tidal surge, or storm tide is a coastal flood or tsunami-like phenomenon of rising water commonly associated with low-pressure weather systems, such as cyclones. It is measured as the rise in water level above the ...
s and
tsunami
A tsunami ( ; from , ) is a series of waves in a water body caused by the displacement of a large volume of water, generally in an ocean or a large lake. Earthquakes, volcanic eruptions and underwater explosions (including detonations, ...
s and (often) the harsh environment of salt
seawater
Seawater, or sea water, is water from a sea or ocean. On average, seawater in the world's oceans has a salinity of about 3.5% (35 g/L, 35 ppt, 600 mM). This means that every kilogram (roughly one liter by volume) of seawater has approximat ...
are typical challenges for the coastal engineer – as are the
morphodynamic changes of the coastal topography, caused both by the autonomous development of the system and human-made changes. The areas of interest in coastal engineering include the coasts of the
ocean
The ocean is the body of salt water that covers approximately 70.8% of Earth. The ocean is conventionally divided into large bodies of water, which are also referred to as ''oceans'' (the Pacific, Atlantic, Indian Ocean, Indian, Southern Ocean ...
s,
sea
A sea is a large body of salt water. There are particular seas and the sea. The sea commonly refers to the ocean, the interconnected body of seawaters that spans most of Earth. Particular seas are either marginal seas, second-order section ...
s,
marginal sea
This is a list of seas of the World Ocean, including marginal seas, areas of water, various gulfs, bights, bays, and straits. In many cases it is a matter of tradition for a body of water to be named a sea or a bay, etc., therefore all these ...
s,
estuaries
An estuary is a partially enclosed coastal body of brackish water with one or more rivers or streams flowing into it, and with a free connection to the open sea. Estuaries form a transition zone between river environments and maritime environm ...
and big lakes.
Besides the design, building and maintenance of coastal structures, coastal engineers are often interdisciplinary involved in
integrated coastal zone management, also because of their specific knowledge of the hydro- and morphodynamics of the coastal system. This may include providing input and technology for e.g.
environmental impact assessment
Environmental impact assessment (EIA) is the assessment of the environmental impact, environmental consequences of a plan, policy, program, or actual projects prior to the decision to move forward with the proposed action. In this context, the te ...
,
port
A port is a maritime facility comprising one or more wharves or loading areas, where ships load and discharge cargo and passengers. Although usually situated on a sea coast or estuary, ports can also be found far inland, such as Hamburg, Manch ...
development, strategies for coastal defense,
land reclamation
Land reclamation, often known as reclamation, and also known as land fill (not to be confused with a waste landfill), is the process of creating new Terrestrial ecoregion, land from oceans, list of seas, seas, Stream bed, riverbeds or lake ...
, offshore
wind farm
A wind farm, also called a wind park or wind power plant, is a group of wind turbines in the same location used to produce electricity. Wind farms vary in size from a small number of turbines to several hundred wind turbines covering an exten ...
s and other energy-production facilities, etc.
Specific challenges

The coastal environment produces challenges specific for this branch of engineering: waves, storm surges, tides, tsunamis,
sea level
Mean sea level (MSL, often shortened to sea level) is an mean, average surface level of one or more among Earth's coastal Body of water, bodies of water from which heights such as elevation may be measured. The global MSL is a type of vertical ...
changes,
sea water
Seawater, or sea water, is water from a sea or ocean. On average, seawater in the world's oceans has a salinity of about 3.5% (35 g/L, 35 ppt, 600 mM). This means that every kilogram (roughly one liter by volume) of seawater has approximate ...
and the
marine ecosystem
Marine ecosystems are the largest of Earth's aquatic ecosystems and exist in Saline water, waters that have a high salt content. These systems contrast with freshwater ecosystems, which have a lower salt content. Marine waters cover more than 7 ...
.
Most often, in coastal engineering projects there is a need for
metocean conditions: local wind and wave climate, as well as statistics for and information on other
hydrodynamic quantities of interest. Also,
bathymetry
Bathymetry (; ) is the study of underwater depth of ocean floors ('' seabed topography''), river floors, or lake floors. In other words, bathymetry is the underwater equivalent to hypsometry or topography. The first recorded evidence of wate ...
and
morphological changes are of direct interest. In case of studies of sediment transport and morphological changes, relevant properties of the sea bed sediments, water and ecosystem properties are needed.
Long and short waves

The occurrence of wave phenomena – like sea waves, swell, tides and tsunamis – require engineering knowledge of their physics, as well as models: both
numerical models and
physical models. The practices in present-day coastal engineering are more-and-more based on models
verified and validated by experimental data.
Apart from the wave transformations themselves, for the waves coming from deep water into the shallow coastal waters and
surf zone
The surf zone or breaker zone is the nearshore part of a body of open water between the line at which the waves break and the shore. As ocean surface waves approach a shore, they interact with the bottom, wave shoaling, get taller and steeper, an ...
, the effects of the waves are important. These effects include:
* the wave loading on coastal structures like
breakwaters,
groyne
A groyne (in the U.S. groin) is a rigid aquatic structure built perpendicularly from an ocean shore (in coastal engineering) or a river bank, interrupting water flow and limiting the movement of sediment. It is usually made out of wood, concrete ...
s,
jetties,
sea walls and
dikes
* wave-induced currents, like the
longshore current
Longshore drift from longshore current is a geological process that consists of the transportation of sediments (clay, silt, pebbles, sand, shingle, shells) along a coast parallel to the shoreline, which is dependent on the angle of incoming w ...
in the surf zone,
rip current
A rip current (or just rip) is a specific type of water current that can occur near beaches where waves break. A rip is a strong, localized, and narrow current of water that moves directly away from the shore by cutting through the lines of bre ...
s and
Stokes drift, affecting sediment transport and morphodynamics
* wave agitation in harbors, which may result in harbor
downtime
In computing and telecommunications, downtime (also (system) outage or (system) drought colloquially) is a period when a system is unavailable. The unavailability is the proportion of a time-span that a system is unavailable or offline.
This is ...
* wave overtopping over seawalls and dikes, which may e.g. threaten the stability of a dike
Underwater construction
Coastal engineering takes place at or near the interface between land and water. Consequently a significant part of coastal engineering involves underwater construction, particularly for foundations. Breakwaters, sea walls, harbour structures like jetties, wharves and docks, bridges, tunnels, outfalls and causeways usually involve underwater work.
Sustainability and soft engineering
In recent decades, coastal engineers have favored non-structural solutions, which avoid adverse impacts that are typically cause by structures, such as sea walls, bulkheads, jetties, etc. These solutions include
beach nourishment, marsh restoration/creation, and habitat restoration. More recently, beneficial use of dredge material, which utilizes material dredged for navigation maintenance to nourish beaches and restore
wetland
A wetland is a distinct semi-aquatic ecosystem whose groundcovers are flooded or saturated in water, either permanently, for years or decades, or only seasonally. Flooding results in oxygen-poor ( anoxic) processes taking place, especially ...
s. Beneficial use is also employed to increase the elevation of marsh platforms in an attempt to adapt to sea level rise.
Regional sediment management has also become a focus strategy for coastal practitioners. This essentially uses nearshore sediment sources and knowledge of coastal morphology to identify which accretional features can be harvested to bolster erosional areas, understanding the harvested material will continue to accumulate. A common regional sediment management option is to dredge ebb and flood shoals to nourish beaches.
Both beneficial use and regional sediment management recognizes the scarcity of material resources offshore and upland.
See also
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** , to prevent coastal erosion and creation of beach
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** Coastal engineering
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** (CERF)
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Notes
References
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External links
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* – Proceedings of the International Conference on Coastal Engineering (ICCE), held since 1950 (biannually since 1960).
{{Authority control
Civil engineering
Coastal construction