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The effect of sea-level rise in the 21st century on marine structures
along the Mediterranean coast of Israel: An evaluation of physical
damage and adaptation cost
D. Zviely
a
,
*
, M. Bitan
b
, D.M. DiSegni
c
a
The Leon Recanati Institute for Maritime Studies, University of Haifa, 199 Aba Khoushy Ave, Mount Carmel, Haifa, 3498838, Israel
b
Department of Maritime Civilizations, Leon Charney School of Maritime Studies, University of Haifa,199 Aba Khoushy Ave, Mount Carmel, Haifa, 3498838,
Israel
c
The Eitan Berglas School of Economics, Tel Aviv University, P.O.B. 39040, Ramat Aviv, Tel Aviv, 69978, Israel
article info
Article history:
Available online
Keywords:
Sea-level rise
Eastern Mediterranean coast
Overtopping
Marine structures
Damage
Corrective measures
abstract
This study presents estimates of the impact adaptation costs due to damage to coastal and marine
structures located along the Mediterranean coast of Israel caused by sea-level rise in the 21st century.
The study examines the effects on various types of constructions, including seaports, power plants,
marinas, desalination plants, sea walls, detached breakwaters, and bathing beach infrastructures for sea-
level rises of 0.5 m and 1 m. To this end, we conduct an analysis of hydrodynamic forces on the structures
and an uncertainty analysis of their occurrence. The study find that the impact of wave overtopping of
breakwaters can lead to extensive damage to port infrastructure and to the vessels moored inside.
Adaptation costs are computed as the corrective measures to be taken to maintain the functionality of
the structures.
©2014 Elsevier Ltd. All rights reserved.
Introduction
A large number of marine structures are situated along the
Mediterranean coast of Israel, including ports, marinas, power
station cooling water stilling ponds, coal unloading jetties,
seawater desalination plants, various drain lines to the sea, mooring
buoys for unloading fuel and natural gas, detached breakwaters,
groynes, sea walls, promenades, vacation and sailing facilities, and
archaeological sites (Fig. 1). These structures play a significant role
in shaping the geography and economy of Israel.
In 2007, the Intergovernmental Panel on Climate Change (IPCC),
acting on behalf of the UN Environment Programme (UNEP) and
the World Meteorological Organization (IPCC., 2007), reported that
sea-level rose rapidly from the mid-19th century until the end of
the 20th century, at an average rate of 2 mm per year. In some areas
sea-level has risen faster, and in others it has dropped. Several
papers analyzing the change in sea-level along the coast of Israel in
the 20th century were published in the past decade. Among them is
an analysis of a series of sea-level measurements from Ashkelon,
Ashdod, and Tel Aviv (Fig. 1) from 1958 to 2001 (Shirman, 2004),
which indicated that there was a sharp rise of more than 100 mm in
sea-level along the Mediterranean coast of Israel from 1990 to 2001.
This rise is additional to a previous rise of 50 mm from 1977 to 1991.
Sea-level measurements taken at the end of the coal unloading pier
at the Hadera power plant also indicated a rise of 100 mm from
1992 to 2002 (Lichter, Zviely, Klein, &Sivan, 2010). This rate is much
higher than the 1.0e1.8 mm per year measured during previous
decades. Since the beginning of the 21st century, the rate of sea-
level rise has slowed, and the average measured rise at Hadera
was 6.1 mm per year from 2001 to 2013 (Rosen, 2013).
The fifth IPCC report (2013) predicts that by the end of the 21st
century sea-level will be 26e97 cm higher than at present. This
prediction has been challenged at both ends of the scale. A number
of researchers claim that it is too conservative, and that global sea-
level will rise much more (Grinsted, Moore, &Jevrejeva, 2010;
Horton et al., 2008; Rahmstorf, 2007; Vermeer &Rahmstorf,
2009). In contrast, other researchers claim that these predictions
are excessive, and that if sea-level does rise, it will be at a much
slower rate (Church &White, 2006; Hunter, 2009). Overall, this is
higher than the previous prediction (IPCC., 2007), which estimated
that sea-level will only rise by 18e59 cm.
*Corresponding author. Tel.: þ972 52 5805758.
E-mail address: zviely@netvision.net.il (D. Zviely).
Contents lists available at ScienceDirect
Applied Geography
journal homepage: www.elsevier.com/locate/apgeog
http://dx.doi.org/10.1016/j.apgeog.2014.12.007
0143-6228/©2014 Elsevier Ltd. All rights reserved.
Applied Geography 57 (2015) 154e162
The present study has three objectives:
1. To survey the marine structures along the Mediterranean coast
of Israel affected by sea-level rise during the 21st century.
2. To estimate the impact of sea-level rise (of 0.5 m and 1 m) on a
range of key marine structures. These sea-levels have been
chosen merely to illustrate and quantify the damage to the
structures, and are not intended to take a stand on disagree-
ments in the scientific community regarding the expected
extent of sea-level rise in the current century.
3. To estimate the minimum actions required to preserve the
continued unimpaired functioning of these structures under the
physical and environmental impact of sea-level rise.
Previous research focusing on damage caused by the rise in
sea-level in the 21st century
Economic valuation of the damage caused by sea-level rise on
coastal areas around the World has focused mainly on the direct
economic damage caused by migration and loss of workplaces.
Dasgupta, Laplante, Meisner, Wheeler, and Jianping (2007) present
an assessment of the damage and economic cost in 84 developing
countries, as a result of a 1 me5 m rise in sea-level during the 21st
century. According to this study, the physical effects of the rise of
sea-level in the eastern Mediterranean and North Africa are rela-
tively minor compared to those in other areas of the world. In these
areas the flooding as a result of a 1 m rise in sea-level would affect
0.25% of the land area, leading to a relatively high rate of migration
(3.2% of the total population, compared to 1.28% on a global scale)
and a reduction of 1.5% of the GrossNational Product (GNP) of those
countries. Such trends were also supported by the study of Bosello,
Roson, and Tol (2007), which evaluated the potential damage to
various coastal areas around the world, while focusing on the loss
of urban areas, agricultural crops, and industrial products, and
population migration on a macroeconomic scale. Hinkel and Klein
(2009) and Hinkel, Nicholls, Vafeidis, Tol, and Avagianou (2010)
focused on the impact of sea-level rise in the European Union
countries, according to two scenarios presented in the IPCC reports:
Scenario A2, in which population growth and greenhouse gas
emissions continue at the current rate (business as usual), and
Scenario B1, which estimates a maximum value of the above two
parameters until 2050, after which they will slow down. Subject to
these scenarios, and assuming no adaptation, the total monetary
damage caused by flooding, salinity intrusion, land erosion, and
migration was projected to be about US$ 17 billion in both scenarios
in 2100. This suggests that taking measures to adapt to sea-level
rise would be beneficial and affordable, and would be widely
applied throughout the European Union.
Lichter and Felsenstein (2012) and Felsenstein and Lichter
(2014) mapped the area in the eastern Mediterranean most sensi-
tive to sea-level rise, using the GIS with a digital elevation model
(DEM) of the surface, with a vertical accuracy of ±2 m, and
considered the impact on the economy of Israel in four scenarios of
sea-level rise: 0.5, 1, 1.5, and 2 m. They provided a spatial estimate
of the geographic impact of sea level rise on Israeli residential and
industrial, and quantified the value of built residential and indus-
trial that could be affected by sea level rise. According to these
studies, the impact of sea level rise on inland infrastructures is
expected to result in loss of habitat area and earnings that are
estimated at the level of $47 million and $95.5 million per year, for
sea level rise of 0.5 m and 1 m respectively.
However, neither of these studies takes into consideration the
impact of sea level rise on the marine structures and its direct
Fig. 1. Marine structures along the coast of Israel chosen for the study.
D. Zviely et al. / Applied Geography 57 (2015) 154e162 15 5
contribution to the protection of inland constructions and eco-
nomic activities. Existing marine structures e.g. detached break-
waters, groynes, sea walls and promenades often provide direct
economic benefit for the transportation, tourism, and agricultural
sectors; and indirect benefits, such as preventing landscape
degradation and ensuring seashore protection. Failure to consider
the existence of marine structures, and their contribution to the
inland geography and economy, may lead to biased conclusions
with respect to the impact of sea-level rise on the economy.
Adaptation to preserve the functionality of marine structures
could result in cost savings due to sea level impact on residential
and industrial. Evaluations of the possible damage to key marine
structures and the adaptation costs involved in preserving their
functionality subject to sea level rise are important component for
further setting geographic adaptation and economic strategies to
coop with climate change impact.
In line with this approach, Ng and Mendelsohn (2005), focused
on the effects of the rise in sea-level until the end of the 21st century
in Singapore, using three separate scenarios (sea-level rise of 0.20 m,
0.49 m, and 0.86 m), while comparing the feasibility and costs of
constructing coastal protection (sea walls, breakwaters, groynes) vs
the cost to the economy from loss of valuable of commercial land.
There, the cost-benefit analysis indicated a clear preference for the
construction of coastal protection over doing nothing.
The costs of restoring the Victoria Port facilities in Hong Kong, as
a result of a rise in sea-level, were quantified by Yim (2012). The
calculation of the expected damage was based, among other fac-
tors, on the probability of the recurrence of an extreme event. The
findings indicated that in order to deal with a 0.5 m sea-level rise, it
will be necessary to increase the height of 46 km of existing sea
walls by 0.5 m; and in the case of a 1 m rise by 1 m.
Changes in wave characteristics in the vicinity of marine
structures
Various natural phenomena could affect the operation of marine
structures, although the most common and significant along the
Mediterranean coast of Israel is wave overtopping (Fig. 2). This
happens when waves striking the marine structure (e.g. port or
marina), overwhelm the breakwater and penetrate the sheltered
area within, which can lead to extensive damage to the breakwater,
port facilities and the vessels inside. This phenomenon is assessed
by using a parameter which combines the frequency and number of
waves striking the breakwater, and wave intensity (m
3
/s) along the
breakwater. The number of waves overtopping the breakwater as a
percentage of the total number of waves striking it is critical in
planning the height of the breakwater. Effective planning requires
hydraulic laboratory testing and a decision regarding the design of
the upper layer of armor of the breakwater by, for example,
installing concrete elements such as Tetrapods, Acrropodes,
Dolosses, or Antifer blocks (Franco, Gerlomi, &Van der Meer, 1994;
Van der Meer, 1998). The greater the ratio between the significant
wave height (Hs) and the height of the breakwater, the greater is the
probability and intensity of wave overtopping (Jensen &Sorensen,
1979). Thus, it is clear that a rise in sea-level will increase this ra-
tio, and the effect of the waves beyond the breakwater, reducing its
effectiveness and increasing the vulnerability of the protected area.
A phenomenon affected directly by wave overtopping is wave
agitation (Fig. 3), which occurs within bays, ports, anchorages, and
other areas sheltered from waves. In ports, wave agitation causes
breakage of mooring cables, damage to fenders, and movement of
vessels. The waves can create strong currents, leading to uncon-
trolled movements of vessels inside the port, sometimes resulting in
collisions (Kofoed-Hansen, Kerper, Sorenen, &Kirkegaard, 2005).
The intensity of wave agitation depends on the unique structure of
each port (shape, length, design of piers, and depth) and charac-
teristics of the waves penetrating from the open sea (wave height,
frequency, wave length) (Al-Salem, 2009). Additional factors
contributing to the progression of waves inside a port are wind gusts
and the interface between short waves and swell at the entrance to
the port, leading to a piling up of long waves inside the port.
Below are the main categories of damage to marine structures
which could be expected as a result of a sea-level rise:
1. Increased dynamic pressure on breakwaters due to wave over-
topping, which increases maintenance costs.
2. Flooding and interruption to operation of the marine structure.
3. Endangering the safety of vessels in ports, marinas, etc.
4. Incompatibility between heights of cargo ships and loading
areas, changes in ship trim and the use of ballast water, and
extended waiting periods at the port.
5. Rise in groundwater level and sea-level below the piers,
undermining their stability.
6. Difficulty in keeping coastal power plants operational, due to
increase in wave agitation in stilling ponds.
7. Problems in draining power plant cooling water and concen-
trate from desalination plants and other discharges.
8. Swash of waves over coal jetties causing long periods of inter-
ruption of operations
9. Damage to urban infrastructure adjacent to marine structures.
Fig. 2. Wave overtopping Caesarea old harbour main breakwater 26.11.2004. Fig. 3. Wave agitation in Ashdod Port during winter storm (Limor Edri, 30.1.2013).
D. Zviely et al. / Applied Geography 57 (2015) 154e162156
These damages amount to direct economic damage to marine
structures, and indirect damage to economic systems, depending
on the structures.
Methodology
This is a representative case study of selected marine struc-
tures located along the Israeli Mediterranean coast of Israel,
carried out in 2012. The survey was conducted using maps, aerial
photographs, and coastal and marine inspections. The marine
structures were classified according to their physical character-
istics, geographical location, and function. The survey included 74
significant marine structures, comprising two main seaports
(Ashdod and Haifa), twelve marinas and small harbors, five
coastal power station cooling water stilling ponds and drain lines
to the sea (hot water), two coal unloading jetties on piles (Ash-
kelon and Hadera), five mooring buoys for unloading fuel and
natural gas, four large desalination plants, a facility for maritime
agriculture, 23 detached breakwaters, seven groynes, eight urban
promenades, and five archaeological sites. The survey did not
include industrial drain lines to the sea, urban sewerage systems,
and other drain lines across the beaches. These have a minor
impact on the national scale, do not fit a general model, and need
specific treatment.
A representative sample of each structure was chosen. The
sample included structures of particular importance, which affect
international trade, energy and water sectors, and collective social
and cultural activities for the Israeli public (Fig. 1).
In order to understand the operational effects and damage
caused by rising sea-level on the chosen marine structures, in-
terviews were conducted with 21 installation managers, pilots of
coal and oil tankers, and maritime engineers involved in the con-
struction, operation and maintenance of these structures.
The final stage of the study was constructed according to a
physical model in order to evaluate the corrective measures
required to repair the expected damage to the chosen structure.
The following basic assumptions were made in order to apply
this model to the structures:
1. The goal of modification and maintenance activities to marine
structures along the coast of Israel necessitated by sea-level rise
will be to sustain the current rate of operation (at the end of
2012).
2. Future technological advances and developments, which could
significantly affect the structure or eventually replace it, are not
included in the analysis.
3. Solutions which suggest protecting marine structures using
measures that result in abandoning the structure, are not viable
options.
The corrective measure framework
This study presents a conceptual framework for estimating and
computing the conservation activities needed as a function of the
area of the structure, structural modifications required, significant
wave height, structure height above sea level (measured as Zero of
Geodetic Height eZGH), depth of water at the sea front of the
structure or in its vicinity, type of structure, specific gravity and
solid fraction of the structure (in the case of a porous breakwater),
and specific gravity, solid fraction and weight of the material of the
protective armor elements.
The corrective measures are the modifications to structural
units required to maintain their operation at a functional level. The
scale of modification required varies in direct proportion to the
rise in sea-level, and depends directly on the probability of a
significant wave height, depth of water at the sea front, and type
of structure.
The general corrective measure is defined as
D
S
i
where
D
S
i
is the
addition required for the structure (m
2
/m
3
/ton)
i¼1denotes a porous marine structure (e.g. port breakwater,
detached breakwater, groyne).
i¼2denotes a sealed structure (e.g. concrete pier, sea wall).
S
1
represents the structural addition to a porous structure, and
is calculated as:
DS
1
¼LWDr
1
FRh(1)
where these are functions of the following variables:
L¼length of structural addition (m)
W¼width of structural addition (m)
Dr
i
¼structural height (porous/sealed) change coefficient.
F¼solid fraction of the protection element material
R¼specific gravity of the protection element
h¼height of the top of the structure above ZGH (m)
The structural change coefficient for a porous structure is pre-
sented in this model as:
Dr
l
¼0:7DE
1
þ0:3Dc
1
(2)
where
D
E
1
represents the change in energy striking the structure,
while
D
c
1
represents the change in wave celerity when striking the
structure, both as a result of a 0.5 m and 1 m rise in sea-level. The
values of E
i
and c
i
are calculated based on an algorithmic interface
developed at Delaware University, USA, using wave calculator
software. The algorithm calculates the main factors affecting the
marine structure: energy (W/m width, wave celerity (m/s), wave
celerity at the bottom of the structure (m/s), wavelength (m), and
wave refraction coefficients).
D
S
2
represents the structural addition to a sealed structure, and
is calculated as:
DS
2
¼LWDr
2
(3)
The change coefficient for a sealed structure is represented by:
Dr
2
¼3:4eh
2
(4)
where, for example, 3.4 is the planned height for the new Haifa Port
and h
2
is the existing height of the sealed structure.
The model is based on maintaining the structure at the current
level of operation, and the restoration does not include potential
damage to the ecological system adjacent to the structure, which
cannot be restored. These factors are calculated as a function of the
significant wave height, wave frequency, wave direction, and depth
of water at the sea front of the structure. The solid fraction and
specific gravity of the structure's protective armor are presented in
Table 1.
Table 1
Specific gravity and solid fraction of materials of marine protective layer.
Details Stone layer Dolos layer Tetrapod layer Antifer layer
Void fraction 0.37 0.63 0.5 0.47
Solid fraction F 0.63 0.37 0.5 0.53
Specific gravity
of protective
element R
2.6 2.4 2.4 2.4
D. Zviely et al. / Applied Geography 57 (2015) 154e162 157
Table 2
Calculation of change coefficient for porous structure
Dr
1
as function of energy and celerity of wave striking marine structure.
Depth of water
at sea front of
structure (m)
Change in
depth (%)
Energy according
to algorithm
E (W/m)
Change in
energy
D
E
i
(%)
Wave celerity
according to
algorithm C (m/s)
Change in
celerity
D
C
i
(%)
Change
coefficient
Dr
1
Herzliya
Marina main
break-water
Dr
1
Herzliya Marina
secondary
breakwater
Dr
1
Ashdod port old
break-water
Dr
1
Ashdod port new
break-water
Dr
1
Ashdod port
secondary
break-water
Dr
1
123 45 678 9 1011 12
1.0 2.4 3.1
1.5 50.0 6.6 175.0 3.8 22.6 129
2.0 33.3 13.6 106.1 4.4 15.8 79 0.78
2.5 25.0 23.6 73.5 4.9 11.4 55 1.89
3.0 20.0 37.1 57.2 5.3 8.2 42
3.5 16.7 54.3 46.4 5.8 9.4 35
4.0 14.3 75.5 39.0 6.2 6.9 29
4.5 12.5 100.8 33.5 6.5 4.8 25 0.25 0.25
5.0 11.1 130.5 29.5 6.9 6.2 22 0.54 0.54
5.5 10.0 164.8 26.3 7.2 4.3 20
6.0 9.1 203.7 23.6 7.5 4.2 18
6.5 8.3 247.6 21.6 7.8 4.0 16
7.0 7.7 296.5 19.7 8.0 2.6 15
7.5 7.1 350.5 18.2 8.3 3.8 14
8.0 6.7 409.7 16.9 8.6 3.6 13
8.5 6.3 474.3 15.8 8.8 2.3 12
9.0 5.9 544.3 14.8 9.1 3.4 11
9.5 5.6 619.8 13.9 9.3 2.6 11
10.0 5.3 700.9 13.1 9.6 2.4 10
10.5 5.0 793.6 13.2 9.8 2.3 10
11.0 4.8 887.2 11.8 10.0 2.1 9
11.5 4.5 986.7 11.2 10.2 2.1 8
12.0 4.3 1092.1 10.7 10.4 2.0 8
12.5 4.2 1203.5 10.2 10.6 1.9 8
13.0 4.0 1321.1 9.8 10.8 1.8 7
13.5 3.8 1444.7 9.4 11.0 1.7 7
14.0 3.7 1574.5 9.0 11.2 1.7 7 0.07
14.5 3.6 1710.4 8.6 11.3 1.6 7 0.14
15.0 3.4 1852.6 8.3 11.5 1.5 6
15.5 3.3 1979.0 6.8 11.7 1.4 5
16.0 3.2 2131.0 8.5 11.8 1.5 6
16.5 3.1 2147.4 0.0 12.0 1.4 0.4
17.5 2.9 2147.4 0.0 12.3 1.3 0.4
18.0 2.9 2147.4 0.0 12.5 1.2 0.4
18.5 2.8 2147.4 0.0 12.6 1.2 0.4 0.004
19.0 2.7 2147.4 0.0 12.8 1.1 0.3 0.007
19.5 2.6 2147.4 0.0 12.9 1.1 0.3
20.0 2.6 2147.4 0.0 13.0 1.1 0.3
D. Zviely et al. / Applied Geography 57 (2015) 154e162158
The change coefficient of the various structures,
Dr
i
, is calcu-
lated according to the equations presented in the model, and
detailed in Table 2. The calculation refers to the change in energy
and celerity of the wave relative to the change in waterdepth at the
structure's sea front. It can be seen that the rate ofchange in energy
is faster than the change of celerity. The main results are presented
as the change coefficient for 0.5 and 1 m sea-level rise as a function
of current water depth at the sea front of the structure.
The values of the variables used to calculate wave energy and
celerity are those used for engineering breakwaters in Israel. The
maximum wave height (Hmax) in deep water is 15.41 m, and the
wave frequency is 14 s
1
. The depth of water at the sea front of the
structure depends on the structure's conditions. Fig. 4 represents
the ratio between the depth of water at the sea front of the marine
structure and the energy of the wave. The shallower the water, the
higher is the marginal change in wave energy. In depths greater
than 16 m the change is minor, and approaches asymptotic.
Fig. 5 represents the ratio between water depth at the sea front
of marine structures and celerity. The celerity increases in direct
proportion to the depth of water.
Calculations of the wave energy and celerity versus water depth
at the seaward face of the structure show that the wave energy is
more sensitive to the depth of water than is the celerity (Figs. 4 and
5and Table 2). Mathematical comparison shows that the effect on
the marine structure of wave energy (0.5e0.7 of the total effect) can
be more than double that of the celerity (0.3e0.5 of the total effect).
In the current model we use the value of 0.7 for energy effects and
0.3 for celerity effects.
For the purpose of this study, the calculations refer to protective
units of a type and size found in each specific breakwater. Table 3
presents the corrective measures to be adopted for the chosen
structures.
The following presents detailed corrective measures for three
marine structures:
1. Ashdod Port (Fig. 1) The bulk of international trade passing
through Israeli seaports accounts for 98% of the total import/
export cargo tonnage and 62% of Israel's GNP, one of the highest
in the world. Calculations of effects on breakwaters and piers in
Ashdod Port are summarized in Tables 3 and 4. Pier calculations
Table 3
Summary of direct corrective measure and volume of addition for selected marine structures.
Structure Corrective measures
I
Addition of building material
for 0.5 m sea level rise ton
II
Risk
coefficient
III
Addition of building material
for 0.5 m sea level rise ton
IV
Addition of building material
for 1.0 m sea level rise ton
V
Haifa Port main
breakwater
Raising breakwaters at sea
front and paving new road
on breakwater
102,402 0.64 65,537 223,565
Haifa Port secondary
breakwater
Raising breakwaters at sea
front and paving new road
on breakwater
43,647 0.64 27,934 91,157
Kishon Port main
breakwater
Raising breakwaters 21,509 0.64 13,765 46,507
Kishon Port secondary
breakwater
Raising breakwaters 6454 0.64 4130 13,431
Haifa and Kishon
ports piers
Raising piers and fixing
infrastructure
1629 0.38 619 3356
Ashdod Port main
breakwater
Raising breakwaters at sea
front and paving new road
on breakwater
398,465 0.64 255,017 799,218
Ashdod Port secondary
breakwater
Raising breakwaters at sea
front and paving new road
on breakwater
9805 0.64 6275 19,984
Ashdod Port piers Raising piers and modifying
infrastructure
813 0.38 308 2461
Orot Rabin power station
main breakwater
Raising breakwaters at sea
front and paving new road
on breakwater
103,194 0.80 82,555 222,899
Orot Rabin power station
secondary breakwater
Raising breakwaters at sea
front and paving new road
on breakwater
24,939 0.80 19,951 55,037
Water cooling drainage
Orot Rabin power
station
Raising drainage channel 4400 0.80 3520 8800
Herzliya Marina main
breakwater
Raising breakwaters at sea
front and paving new road
on breakwater
35,279 0.80 28,223 77,022
Herzliya Marina
secondary breakwater
Raising breakwaters at sea
front and paving new road
on breakwater
40,329 0.80 32,263 96,501
Herzliya Marina
beach piers m
3
Raising piers and fixing
infrastructure
47 1.0 47 282
Desalination plant water
discharge pipe ekm
Addition of pipe identical
to existing pipe
2.5 0.16 0.4 2.5
Caesarea National
Park sea wall
Raising and strengthening
existing wall
450 0.8 360 900
Tel-Aviv beach detached
breakwaters
Raising breakwaters 9819 1.0 9819 23,930
Beach infrastructure
(promenades) m
3
Rebuilding and raising
sea-wall
290,400 1.0 290,400 290,400
D. Zviely et al. / Applied Geography 57 (2015) 154e162 15 9
are based on the various heights of the piers up to 3.4 m, ac-
cording to Haifa Bay port's pier plans. It is important to note that
a 20 cm rise in sea-level was taken into account in the planning
of the expansions of Haifa Port (the “Bay Port”) and Ashdod Port
(the “Southern Port”), in addition to a 10 cm rise from the
beginning of the century.
2. Herzliya Marina (Fig. 1) The largest marina in Israel, it was
constructed between August 1990 and September 1992. The
marina can berth 756 vessels of different sizes, and is a catalyst
for business and urban and tourism development.
The sheltered water inside the Marina is protected by the main
breakwater, 1160 m long and 5.5 m above ZGH, and by a secondary
breakwater 335 m long and 4.2 m above ZGH. Water depth at the sea
front of the structure is 3.5 m, and the infrastructure is made of
structural stones armored with 8000 Dolosses of two sizes, 10 and
18 tons. The anchorage consists of 16 finger piers, of total length
1129 m, and additional piers, with a total length of 940 m, bordering
the main structure. The height of the piers is 1.6e1.7 m above ZGH.
Modifications to breakwaters at Herzliya Marina are estimated
to require the addition of 35,000 and 77,000 tons of Dolos for sea-
level rise of 0.5 m and 1.0 m respectively (Table 3).
3. Palmachim desalination plant (Fig. 1) The plant was built by
Maris Desalination Ltd. north-east of kibbutz Palmachim. It covers
an area of 5 ha, and is located 800 m from the coastline. In the plans
authorizing the plant in 2004, the capacity of the plant was 30
million m
3
/year of desalinated water, with a flow of reject
concentrate of 6000 m
3
/hour. Since then, the plant has been
expanded, and the concentrate discharge pipe to the sea has been
extended in order to increase desalinated water production to 90
million m
3
/year.
Concentrate discharge into the sea from the desalinationplant is
by gravitation through a pipe 2500 m long, the discharge end of
which is 2 km from the coast, at a depth of 20 m. The concentrate
passes through a buffer tank 11 m high, with a high water level of
8 m above ZGH, and a working water level of 4 m. The current dif-
ference between the surface level of concentrate and sea-level
creates a hydraulic head which is sufficient to allow an efficient
discharge of concentrate into the sea. In a scenario in which sea-
level rises by 1 m during the 21st century, the hydraulic head and
the pressure in the pipe will decline. This will require raising the
surface level of concentrate in the buffer tank. However, the addi-
tional height in the buffer tank which is not currently utilized will
still provide sufficient flow rate. Only in a situation in which the
pressure drop in the pipe is greater than the head in the buffer tank
will there be a need for an additional concentrate pipe (Eli Sivan,
pers. comm.). The length of an additional concentrate pipe, identical
in length to the existing one, would be 2.5 km (Table 3). It should be
noted that, although the probability of actually incurring this cost is
extremely low, the overall restoration cost of the marine structures
and facilities has been taken into consideration for this study.
Uncertainty considerations
In order to evaluate the damage expected to a marine struc-
ture and facilities, with the probability of the damage occurring
Fig. 4. Ratio between depth of water at the sea front of the marine structure and
energy of wave.
Fig. 5. Ratio between water depth at sea front of marine structure and wave celerity.
Table 4
Repair calculations for Ashdod breakwaters for sea-level rise of 0.5 m and 1 m.
Breakwaters in Ashdod Variable Old main
break-water
New main
break-water
Secondary
breakwater
Height above ZGH (m) h 8 8.4 6
Mean height of structure
from sea floor (m)
23 28.3 no section
Length (m) L 2070 1160 800
Width of sea front
wall (m)
W80 50 25
Mean depth of water
at sea front (m)
4 18 13.6
Slope of sea front 1:2.1 1:2.1 no section
Slope into port 1:1.33 1:1.33 no section
Width of top of
breakwater (m)
8104
Top protection layer Tetrapod Antifer Tetrapod
Solid fraction F 0.5 0.53 0.5
Specific gravity of
armor units
R 2.4 2.4 2.4
Structure change
coefficient for 0.5 m
sea-level rise
Dr
1
0.25 0.004 0.07
Structure change
coefficient for 1 m
sea-level rise
Dr
1
0.5 0.007 0.14
Addition needed for 0.5
sea-level rise tons
D
s
1
395,986 2479 9805
Addition needed for 1 m
sea-level rise tons
D
s
1
794,880 4338 19,984
Table 5
Probability of occurrence of danger to marine structures as result of sea-level rise.
Classification Probability Probability of danger occurring
0.2 Very low Near zero
0.4 Somewhat low Up to 15%
0.6 Low Up to 25%
0.8 Medium 25e75%
1.0 High Over 75%
D. Zviely et al. / Applied Geography 57 (2015) 154e162160
due to a rise in sea-level, the current risk coefficient, which
depends on the probability of the damage occurring, is incor-
porated into the calculation. This evaluates the severity of the
cause of the damage, and some level of forecasting a future sea-
level rise.
Damage caused by events resulting from a 0.5 m sea-level rise
has been calculated, and a uniform distribution of probabilities of
events is assumed. Each marine structure or facility is assigned a
risk factor, presented in Tables 5e7. The risk factor is based on the
level of ongoing maintenance assessed through interviews with
installation managers of each structure. The total risk level for each
structure is detailed in Table 8 and Fig. 6. As an example, the cooling
water drainage system of the Orot Rabin power station in Hadera
has a very high risk probability (100%), with the most serious
consequences. The main breakwaters in Haifa Port, Ashdod Port,
and the coal unloading jetty in Hadera have an 80% probability of
this risk occurring, and its effects are expected to be 80%. In
contrast, the probability of the risk for the breakwater in the Orot
Rabin power station cooling water stilling ponds is identical (80%),
but the expected damage from occurrence of this risk has a very
high probability (100%).
Results
This study deals with the following marine structures: Haifa
Port; Ashdod Port; the Orot Rabin power station stilling pond and
coal jetty; Herzliya Marina; the Palmachim seawater desalination
facility; the sea wall in the Caesarea National Park; the detached
breakwaters at the Tel Aviv beach, and bathing beach in-
frastructures. Table 4 presents the corrective measures to be taken
in order to keep the functionality of a specific marine structure at its
current level. Columns IV and V of Table 4 detail the modifications
needed in each structure, given the decision to modify these marine
structures to cope with a 0.5 m or 1 m sea-level rise. The calculation
for a rise of 0.5 m is incorporated into the uncertainty coefficient in
risk management.
Marine structures with little or no maintenance will be more
exposed to damage due to a sea-level rise. Thus, the column rep-
resenting associated risk in Table 4 takes the full probability of the
damage occurring into account (piers in Herzliya Marina, detached
breakwaters in Tel-Aviv, and coastal infrastructure).
Table 6
Evaluation of severity of cause of threat.
Classification Effect Degree of effect
0.2 None Does not cause damage
0.4 Low Small amount of damage, minor maintenance
0.6 Medium Medium damage, high maintenance
0.8 High Large amount of damage, operational difficulties
1.0 Critical Loss of operability
Table 7
Classification of forecast level.
Classification Level of forecast Forecast possibilities
1.0 Certain Indicators enable almost certain forecast of
cause of danger
0.8 Good Indicators enable reasonable forecast of
cause of danger
0.6 Medium Indicators enable medium level of certainty for
forecast of cause of danger
0.4 Low Indicators enable low level of certainty for
forecast of cause of danger
0.2 Slight Indicators enable little certainty for forecast
of cause of danger
Table 8
Uncertainty coefficient for destruction of marine structures in Israel.
Marine
structure
Breakwaters
in Haifa and
Kishon ports
Piers in Haifa
and Kishon
ports
Breakwaters
in Ashdod
port
Piers in
Ashdod
port
Breakwaters and water
cooling ponds: Orot Rabin
power station
Cooling water
drainage at Orot
Rabin power station
Coal pier at
Orot Rabin
power station
Breakwaters
at Herzliya
Marina
Piers at
Herzliya
Marina
Discharge drainage
at Palmachin
desalination plant
Sea wall
at Caesarea
National Park
Detached
breakwaters e
Tel Aviv
Beach
infrastructure
Probability
from
Table 5
0.8 0.8 0.8 0.8 1.0 1.0 0.8 1.0 1.0 0.2 1.0 1.0 1.0
Severity
from
Table 6
0.8 0.6 0.8 0.6 0.8 1.0 0.8 1.0 1.0 1.0 1.0 1.0 1.0
Level of
forecast
from
Table 7
1.0 0.8 1.0 0.8 1.0 0.8 0.6 0.8 1.0 0.8 0.8 1.0 1.0
Total risk 0.64 0.38 0.64 0.38 0.8 0.8 0.8 0.8 1.0 0.16 0.8 1.0 1.0
D. Zviely et al. / Applied Geography 57 (2015) 154e162 161
Summary and discussion
1. This study develops a general estimation for corrective mea-
sures and a physical model for calculating restoration or
extension for Israeli marine structures, taking into consideration
environmental and physical properties of common marine
structures, including sea-level (a rise of 0.5 m or 1 m), the
characteristics of the structures (type, direction, properties of
protective armor, built area), and changes in wave characteris-
tics in the vicinity of the structures (expected changes in sig-
nificant wave height and the wave force of impact).
2. The study is applied to a sample of marine structures along the
Mediterranean coast of Israel. These comprise two ports (Haifa
and Ashdod), a power station (Orot Rabin), a marina (Herzliya), a
seawater desalination facility, sea walls in the Caesarea National
Park, detached breakwaters at the Tel Aviv beach, and bathing
beach infrastructures.
3. The expected economic impact of maintaining the current level
of operation of these marine infrastructures as a result of sea-
level rise (shown in Table 3), is approximately US$200 million
and US$500 million, for 0.5 m and 1 m sea-level rise, respec-
tively. The costs represent 0.07% and 0.17% of Israel's GDP for
2012, respectively, not including potential loss of property
values due to the rise in sea-level.
Acknowledgments
We wish to thank Prof. Eliezer Kit of the Faculty of Engineering
of Tel Aviv University for his constructive comments.
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D. Zviely et al. / Applied Geography 57 (2015) 154e162162
