category, suggesting extensive shoreline engineering
(Figure 1b). The WPI, which provides information on
only 3,700 ports worldwide, excludes many, mostly small
fishing ports. For example, Japan, with a coastal length of
about 30,000 km, has more than 4,000, 28 % listed as
commercial and 72 % as fishing ports (Shapiro, 1984).
The WPI lists only 292 for Japan.
The structures that are found in ports include piers,
docks, warehouses, and other support facilities. The type
and number of which vary greatly from port to port
depending mainly on their function.
Shoreline protection
“The need for coastal protection only becomes evident as
human activities become established. . .and fixed structures and buildings are constructed. . .” (Gourlay, 1996,
12). Once humans began to fill the coast with dwellings,
roads, industries, and other infrastructure elements, they
often found themselves at odds with nature. According
to Horikawa, beach erosion is “. . .one of the largest world
problems from the perspective of land preservation”
(1978, 327), and Bird (1996) adds emphasis by noting that
75 % of the world’s beaches are in retreat. Human reaction
to coastal erosion has mostly been “stabilized” so that
today artificial structures dominate extensive sections of
the world’s shorelines.
This “hard” or “static” engineering approach centers
around structures that are fixed in position and that have
durability. They include those that are land/sea interface
structures such as seawalls, bulkheads, and revetments.
The seawall is the one “. . .most generally regarded by
the public as representing the best form” (French, 2001,
51). Designed to separate land from sea, it in essence
becomes an artificial cliff. Some, like the one along a
typhoon-prone area on the Pacific coast of Japan, are more
than 12 m high. Japan’s coastline, much of which is also
threatened by tsunami, has more than 8,000 km of dykes
and seawalls.
Breakwaters, designed to eliminate or reduce wave
action, are used to protect the shore behind or adjacent to
them. Most early breakwaters were attached to the shore,
especially in connection with harbors. Today they are also
constructed off shore. They are especially abundant in
Italy and Japan. In the USA, along the southern coast of
California, detached breakwater construction began in
1899 and eventually extended along 14 km of shoreline
(U.S. Army, 1977). Other hard structures include jetties
and groins (Figure 1c). They are nonparallel structures
designed to protect river entrances from silting (jetties)
and to trap long-shore drift and combat shore erosion
(groins).
The materials of which such structures are made are
highly varied. Natural rock as rubble and riprap was the
traditional material, although timber, steel piling, and,
more recently, manufactured armor blocks are also used.
The first fabricated armor unit was a simple concrete block
that served as a substitute for natural boulders. In 1950 the
French designed an interlocking unit called “tetrapod”
which subsequently led to numerous designs including
dolos (South Africa), akmon (the Netherlands), trumpets
(Spain), and more than 30 others in Japan with such
names, when translated from the Japanese, as spindle, turtle, and igloo (Walker, 1988).
The extent and character of an engineered shoreline
varies greatly from one country or locale to another and
depends not only on the nature of the coast itself but also
on how humans, with their varied population densities,
histories, cultural preferences, and technological expertise, have adapted to it. For example, less than 2 % of Finland, with its hard-rock, rebounding coast, is bordered by
artificial structures, whereas more than 85 % of the coastline of Belgium is so bordered.
Soft engineering
Hard engineering has been the most common method of
combating coastal erosion despite the fact that it is expensive and often unsightly and frequently aggravates erosion. Recently, a technique that is more compatible with
natural processes has been utilized. Basically, it is the
replenishment of the sand that has been removed from a
beach by erosion. The first example of such an engineering feat may have been the creation of a beach in Turkey
with sand shipped from Egypt more than 2,000 years
ago for Cleopatra (El-Sammak and Tucker, 2002). Today,
that beach (on the island of Sedir) is a popular tourist destination but one with very strict preservation restrictions.
Beach nourishment, proposed in the United States in
1916, was done sparingly for decades; the first large scale
beach nourishment in Europe was at Norderney, Germany,
in 1951. Beach nourishment mainly elevates the beach and
advances the shoreline, thereby increasing its effectiveness against erosion and, of course, its desirability for recreation. Sediment sources for beach nourishment projects
are varied including from offshore; transport is by truck,
bulldozer, dredge, and pipeline (Finkl and Walker,
2002). Durability also varies; effectiveness averages
between 5 and 10 years, although some, such as Miami
Beach, Florida, last much longer.
Another soft structural procedure is the construction of
dunes which serve as barriers to wave action, locales for
vegetative growth, and reservoirs of sand during storms
(National Research Council, 1990).
Other types of engineered coasts
Although reclamation, ports, and shoreline protection
dominate coastal engineering, there are other modifications that have altered the natural coastal zone. Some
examples include the construction of highways and railways along the top, the bottom, and on the slopes of cliffy
coasts; the creation of flood gates as on the Thames, in
Venice lagoon, and in the Netherlands; the damming of
straits creating fresh water bodies as in Hong Kong; the
construction of offshore islands for drilling platforms as
in the Beaufort and Kara Seas; and the construction of
ENGINEERED COASTS
229
(Figure 1b). The WPI, which provides information on
only 3,700 ports worldwide, excludes many, mostly small
fishing ports. For example, Japan, with a coastal length of
about 30,000 km, has more than 4,000, 28 % listed as
commercial and 72 % as fishing ports (Shapiro, 1984).
The WPI lists only 292 for Japan.
The structures that are found in ports include piers,
docks, warehouses, and other support facilities. The type
and number of which vary greatly from port to port
depending mainly on their function.
Shoreline protection
“The need for coastal protection only becomes evident as
human activities become established. . .and fixed structures and buildings are constructed. . .” (Gourlay, 1996,
12). Once humans began to fill the coast with dwellings,
roads, industries, and other infrastructure elements, they
often found themselves at odds with nature. According
to Horikawa, beach erosion is “. . .one of the largest world
problems from the perspective of land preservation”
(1978, 327), and Bird (1996) adds emphasis by noting that
75 % of the world’s beaches are in retreat. Human reaction
to coastal erosion has mostly been “stabilized” so that
today artificial structures dominate extensive sections of
the world’s shorelines.
This “hard” or “static” engineering approach centers
around structures that are fixed in position and that have
durability. They include those that are land/sea interface
structures such as seawalls, bulkheads, and revetments.
The seawall is the one “. . .most generally regarded by
the public as representing the best form” (French, 2001,
51). Designed to separate land from sea, it in essence
becomes an artificial cliff. Some, like the one along a
typhoon-prone area on the Pacific coast of Japan, are more
than 12 m high. Japan’s coastline, much of which is also
threatened by tsunami, has more than 8,000 km of dykes
and seawalls.
Breakwaters, designed to eliminate or reduce wave
action, are used to protect the shore behind or adjacent to
them. Most early breakwaters were attached to the shore,
especially in connection with harbors. Today they are also
constructed off shore. They are especially abundant in
Italy and Japan. In the USA, along the southern coast of
California, detached breakwater construction began in
1899 and eventually extended along 14 km of shoreline
(U.S. Army, 1977). Other hard structures include jetties
and groins (Figure 1c). They are nonparallel structures
designed to protect river entrances from silting (jetties)
and to trap long-shore drift and combat shore erosion
(groins).
The materials of which such structures are made are
highly varied. Natural rock as rubble and riprap was the
traditional material, although timber, steel piling, and,
more recently, manufactured armor blocks are also used.
The first fabricated armor unit was a simple concrete block
that served as a substitute for natural boulders. In 1950 the
French designed an interlocking unit called “tetrapod”
which subsequently led to numerous designs including
dolos (South Africa), akmon (the Netherlands), trumpets
(Spain), and more than 30 others in Japan with such
names, when translated from the Japanese, as spindle, turtle, and igloo (Walker, 1988).
The extent and character of an engineered shoreline
varies greatly from one country or locale to another and
depends not only on the nature of the coast itself but also
on how humans, with their varied population densities,
histories, cultural preferences, and technological expertise, have adapted to it. For example, less than 2 % of Finland, with its hard-rock, rebounding coast, is bordered by
artificial structures, whereas more than 85 % of the coastline of Belgium is so bordered.
Soft engineering
Hard engineering has been the most common method of
combating coastal erosion despite the fact that it is expensive and often unsightly and frequently aggravates erosion. Recently, a technique that is more compatible with
natural processes has been utilized. Basically, it is the
replenishment of the sand that has been removed from a
beach by erosion. The first example of such an engineering feat may have been the creation of a beach in Turkey
with sand shipped from Egypt more than 2,000 years
ago for Cleopatra (El-Sammak and Tucker, 2002). Today,
that beach (on the island of Sedir) is a popular tourist destination but one with very strict preservation restrictions.
Beach nourishment, proposed in the United States in
1916, was done sparingly for decades; the first large scale
beach nourishment in Europe was at Norderney, Germany,
in 1951. Beach nourishment mainly elevates the beach and
advances the shoreline, thereby increasing its effectiveness against erosion and, of course, its desirability for recreation. Sediment sources for beach nourishment projects
are varied including from offshore; transport is by truck,
bulldozer, dredge, and pipeline (Finkl and Walker,
2002). Durability also varies; effectiveness averages
between 5 and 10 years, although some, such as Miami
Beach, Florida, last much longer.
Another soft structural procedure is the construction of
dunes which serve as barriers to wave action, locales for
vegetative growth, and reservoirs of sand during storms
(National Research Council, 1990).
Other types of engineered coasts
Although reclamation, ports, and shoreline protection
dominate coastal engineering, there are other modifications that have altered the natural coastal zone. Some
examples include the construction of highways and railways along the top, the bottom, and on the slopes of cliffy
coasts; the creation of flood gates as on the Thames, in
Venice lagoon, and in the Netherlands; the damming of
straits creating fresh water bodies as in Hong Kong; the
construction of offshore islands for drilling platforms as
in the Beaufort and Kara Seas; and the construction of
ENGINEERED COASTS
229