(c) Marco Pluijm / June 2016 2
systems which seem to be able to deal with these effects without too much impact. Or no
impact nor damage at all.
A number of these systems have been identified and analyzed on their unique characteristics
and presented here as examples. To mention are:
• Barrier islands
A number of barrier islands in the Mississippi Delta appear to have a natural
resilience towards hurricane impacts. For instance Dauphin Island, which has
survived a number of hurricanes in succession, without too much damage to the
island and on the island. On one occasion the island did develop a gap, breached,
which helped to understand what the limits of resilience in this respect are. With
thorough understanding of the natural processes and due to the natural
characteristics of the system, this gap could be fixed with relative simple means. The
conclusion in this case is that the system’s natural resiliency performed well during all
events and only once needed a bit of human support to recover, still based on natural
These systems are renowned for their natural resiliency, mainly due to their extensive
and spread out root systems. Mangroves are very effective in reducing waves and
therefore in protecting vulnerable coastlines. The systems themselves are vulnerable
to climate change as such. Which needs careful monitoring and when needed,
mitigation where possible. Healthy mangrove areas usually fully recover after an
extreme event. In some cases, for instance when large quantities of sediment have
moved around during the storm, settled and cover their root systems, human
intervention may be required to remove that overburden. For instance by controlled
flushing. An option, which will be highlighted later on in this paper.
Figure 1: Dauphin Island (US) under normal conditions and spilling during an extreme event
Figure 2: Mangrove System
(c) Marco Pluijm / June 2016 3
• Dune coasts
Like mangroves, dune coasts are renowned for their natural resiliency. Due to their
natural dynamics and flexibility they are able to withstand super-storms and recover
afterwards. During the storm event the dune-front erodes, with the eroded sand
settling on the foreshore, thus reducing the wave impact, slowing down the overall
effect. After the event, cross-shore sand transport brings the sand back, with the wind
taking care of the dry parts, settling again along the dune-front.
• Polder systems
Polders in this respect might seem to be a bit of an odd one. Because polders by
definition are manmade. Still in terms of natural resiliency, a lot can be learned from
these systems once built. For instance how their structure of canals, levies and
buffers manages to cope with extreme events. Even after flooding. For instance as
integral element in flood defense systems. Protecting the area behind, even when the
polder area itself would get flooded. An attribute which in itself can be used as part of
the overall resiliency of a coastal area. In particular in those cases where the polder
is used for nature development and conservation. Like the Oostvaardersplassen in
the Netherlands, where inside the diked area (the polder), a large part has been
developed into a nature conservation area. It is the characteristics of this area,
actually an eco-buffer, which helps to develop the polder itself, and so the area
around it, into a resilient and more sustainable environment. And although this polder
is situated inland, the same capacity can be used for enhancing the resilience of
coastal areas in terms of reducing direct storm impact and flooding.
In summary, four examples of systems with built in natural resilience towards extreme event
impacts, which form part of the basis for the “Resilient by Nature” approach, presented here.
Examples for solutions, also in combination with each other, for places less able to cope with
the challenges these impacts impose with increasing frequency and intensity.
Figure 3: Dune Coast
Figure 4: Nature Conservation Polder and Landscape
(c) Marco Pluijm / June 2016 4
Resilient by Nature
With reference to the above, the “Resilient by Nature” approach is based on what can be
learned from natural systems around the globe, which are able to survive and recover from
the impacts of climate change induced extreme events.
Experiences translated into basic dimensions, practical guidelines and tools for the benefit of
other places, which are not able to respond in a similar, adequate way. Solutions either as
standalone components or in combination. In which case reference is made to what is called
, highlighted later on in this paper.
All solutions based on proven performance. Sharing the ability of natural resilience and
sustainability. Systems which can recover either fully by themselves or sometimes with a little
help from outside.
Where “help from outside” is defined as “with local means”. For reasons of sustainability and
efficiency, it is recommended to strive for solutions based on the use of local craft and
capacity. A capacity which was demonstrated for instance in Hue, Vietnam, using sand bags
and local labor to close a major tidal gap in a barrier island, developed after the devastating
floods of 1999. No external efforts were called in. Instead of bringing in international
contractors, the Government decided to solve the problem with local means. This is not a
unique example and should be one of the basic principles to follow throughout the whole
“Resilient by Nature” approach.
Based on the lessons learned and analyses of the various natural systems, a number of
different elements, tools, emerge as building blocks which can be used for enhancement of
more vulnerable systems elsewhere.
The examples from toolbox in its current format contains the following elements or tools:
• Hurricane proportioned barrier breakwaters
In analogy with the behaviour of the barrier islands in the Mississippi Delta, this
concept can easily be translated into breakwater solutions, or other coastal
infrastructure, elsewhere. Main determining parameters are found in width, height
and length. Based on the principle of relative undisturbed flow over and around the
barrier island during the event, instead of attacking it as a rigid structure. Time has
shaped these features according to the wide variety of exposure they have faced
during their lifetime. It’s these dimensions which indicate how similar features can
and should look like on other locations, in another place. The processes usually are
the same, their relative interaction can vary. The concept itself, with addition of
general understanding of coastal processes, can shape any solution elsewhere.
Provided the natural materials (sand or clay) are available.
Figure 5 : Dauphin Island as an example of a Barrier Breakwater
(c) Marco Pluijm / June 2016 5
• Sequential breakwaters
Offshore breakwaters can work well under average conditions, but do have a
reputation of low efficiency with regard to extreme conditions. This changes when
building them like natural sandbank systems With the right dimensions in terms of
height, width and interspacing in relation to the wave attacks they need to be able to
encounter and reduce impact, based on their natural dynamic behaviour. Depending
on the local conditions built as sand banks or as hybrid solutions by adding hard
substrate (rock/concrete elements) or vegetation (eco shields)
• Eco Shields
Enhancement of natural coasts’ resiliency by means of vegetation. Zones of
mangroves or other vegetation, in front of or along a coastline, protecting the area
itself and the hinterland behind it from erosion and flooding. In case the natural
environment is not immediately suitable for such a solution, a combination with a
contained, polder approach might provide the answer (see below).
Eco shields and coastal vegetation can get damaged due to for instance vast
sedimentation and debris during an extreme event. Tidal and nearby river flow shall
be strong enough to remove that sediment overdose, but when the quantities are too
large, the natural system might need help from outside. For instance by controlled
flushing, which in itself can be driven by (controlled) natural processes.
Figure 6 : Near Shore Sand Banks at Low Tide
Figure 7 : Example of an Eco Shield : Guyana Mangrove Restoration Project
(c) Marco Pluijm / June 2016 6
• Extreme Impact Relief Polders
One of the traditional criteria for a polder, is keeping the (sea) water out at all times,
in order to protect what is inside the diked area from flooding.
According to the Resilient by Nature approach, as an alternative, polders are
considered as an effective tool in protecting vulnerable coasts, following a different
Polders as impact relief instrument, actually meant to get flooded during extreme
events. With dikes designed as spilling levies or weirs. Which allows the water to
come in a controlled manner, slowing down the direct impact on the coast behind,
while the polder fills up with seawater. Vegetation in the polder can enhance this
process and so the degree of protection or relief.
After the event, intruded salt water is pushed out by the surface storm water run off,
which flows into the polder from the landside. Again, controlled, via large capacity
In the period before and after the impact, the area inside the polder can be used for
all kinds of purposes, such as agri- or aquaculture. In terms of climate change
resiliency, development as eco-polders with impact resistant vegetation and a varied
landscape, is preferred. Vegetation chosen in accordance with what is most effective
and viable for that specific region.
This concept may lead to an additional advantage or quality. For instance part or all
of the polder can be used for enhanced flushing. A subject mentioned earlier.
In analogy with a facility which is in use along the German coast of the Waddensee,
at Neßmersiel. Where a polder (or: Spülsee) gets flooded with the daily tides and
discharges each time once filled up. Thus keeping the local shipping channel
(fairway) free from siltation for over 30 years now.
Figure 8 : Fully Detached Nature Conservation Polder
Figure 9 : Neßmersiel (Germany) Flush Basin (Spülsee)
(c) Marco Pluijm / June 2016 7
Such (semi-) natural, gravity driven flush mechanism could work with mangrove
zones which are threatened by post event siltation. Or ports and fairways suffering
from post event clogging up with sediments or debris. A common problem and often
hard to tackle in terms of response time, availability of equipment or required draft
and capacity. Such a natural flow system could solve or reduce the problem.
Extreme event impact relief polders can be built near-shore, at relative short distance
in front of a shoreline as kind of detached “breakwaters” or attached to the coastline.
• Offshore Structures
Apart from the climate change induced short event impacts, another related
phenomenon are the changes in the world wave climate. In particular the rapid
changes in long wave energy and bound long waves along various coasts in the
world. Causing an increase in downtime in ports along those coasts, in particular for
the handling of container vessels.
One of the options to deal with this effect and make ports more resilient in this
respect, is to push the affected port infrastructure out to deeper water. Towards a
suitable distance from the coastline, where for instance resonance plays a much
lesser role and the operational wave climate becomes less hostile.
By doing so, offshore port infrastructure offers opportunities for additional benefits
too. Such as homeland security, enhanced bio diversity, commercial fishing (artificial
reefs) and tourism. During and after extreme events, offshore ports can provide the
necessary backup in terms of deep-water port infrastructure, needed for delivery of
goods and equipment and serve as Disaster Relief Centre.
While by doing so, onshore the pressure on the available land areas becomes less,
with a reduction in need for more onshore port development, or even the opposite,
when former terminals which have become inefficient, can be redeveloped into nature
conservation areas. Which in themselve can contribute to the overall resiliency with
regard to extreme event impacts of that area.
Figure 10 : Post Event Masses of Debris
Ref : www.internal-displacement.org
Figure 11 : Yang Shan Offshore Port
(c) Marco Pluijm / June 2016 8
Potential vulnerability of the port equipment (such as the gantry cranes) during an
extreme event can be dealt with by designing them as low drag port infrastructure
In summary, what is presented here is variety of tools as examples of what the Resilient by
Nature approach brings, based on evaluation of the performance of a number of existing
systems around the globe.
Over time more examples, tools, are expected to follow when this concept is adopted by the
international community. Similar to what happened with Building with Nature. Developing
guidelines and tools as things move forwards.
The next step in the process is to demonstrate how this translates into actual solutions for
places without or with insufficient natural resilience in this respect. Two examples are given.
One for Vanuatu, a Small island Development States (SDIS’s) and one for the City of New
Examples of “Resilient by Nature” Solutions
Each coastal area hosts a great deal of functions. One of the specific characteristics of
coastal environments is that they keep on changing their dimensions with time. Functions
may be well defined, due to their characteristics, but their physical appearance most likely
keeps on changing. It is very much a 4-Dimensional environment. In this respect it is probably
better to talk about changing landscapes rather than (discrete) functions.
Landscapes which are interrelated and connected. When one changes, others will respond or
In terms of addressing the qualities and needs for resiliency of coastal areas, mapping of
those needs and assessing their interrelations is done according the method of “Connecting
Landscapes” (see figure 12) Where the Greek symbol “δ” stands for variety and change.
An idea about a number of (generic) landscapes is given in figure 12. How this works out for
two more specific cases, e.g. SDIS’s (Vanuatu example) and New York, USA, is illustrated in
It is noted that these figures are for demonstration purposes only and the actual contents are
open for debate. One of the recommendations is to further define a number of these cases
and start working along this line towards actual integral solutions, suitable to get
Figure 12 : Connecting Landscapes, the δ Approach
(c) Marco Pluijm / June 2016 9
Connecting these images with the toolbox as it is, leads to an array of solutions, depending
on needs, opportunities and urgency of the place. But also provides a picture and
understanding about what is already there and what is needed to reinstate or enhance natural
In particular in case of a number of the SDIS’s, the likely outcome will be that relative small
additions are required in order to make significant steps forward with regard to resiliency for
extreme events. Especially when adding the suggested polder concept is an option. Being a
multi functional add-on with many additional advantages.
For the City of New York the picture is probably a bit different. Much is already there.
Especially when following the “Resilient by Nature“ approach, when applying barrier
breakwaters and concepts such as the disaster relief polders and eco shields (other than
mangroves) in combination with wetland conversation onshore.
In terms of port infrastructure the City of New York is thought to be a perfect example where
an offshore port has significant advantages. Not only for the port infrastructure itself (no draft
restrictions or height limitations), but also in terms of Homeland Security and extreme event
Providing adequate deep water port facilities after the event (not impacted by post-event
siltation) and cargo (container) handling facilities, as well as many backup functionalities
(such as a Disaster Relief Centre or - Mitigation Unit).
Under normal conditions the offshore port and provide additional functionalities for
commercial fishing (hard sub, artificial reefs) and for instance tourism.
The economics behind what’s feasible or not will mainly be determined on the basis of what’s
already there, how much modification is required and what to build from scratch with related
planning and time scales.
Balanced against the immense costs of the economic and financial damage each event
causes. Which usually is a staggering amount. The combined damage of the 6 main storm
events over the past ten years along the US South East and East Coast, adds up to USD 290
billion. Which is an average of USD 29 billion per year. An event like hurricane Sandy (2012,
USD 75 Billion) proves that the damage likely exceeds many times the investments, needed
for creating and maintaining an adequate resiliency level. With the “risk” that a similar, second
event will never hit the State of New York again.
Still, with the rapid increase in climate change induced extreme events, a matter of serious
risk assessment. On the basis of which the Dutch have built their country. And when that
went wrong in 1953, with the big floods in the south of the country, the Delta Plan was pulled
Figure 13 : Connecting Landscapes, SIDS (Vanuatu) and New York (USA) Examples
(c) Marco Pluijm / June 2016 10
out and by itself changed the world of flood protection, environmental impact assessments
and marine construction. Justifying every penny spent since on events that most likely will
never happen again.
When Honzo Svašek kicked off his Building with Nature approach in 1979, no one could
foresee the huge benefits that would bring and has delivered since, globally. An almost global
industry has actually been built on it. Environmental friendly construction became a universal
The same can happen with “Resilient by Nature”. To begin with the right mindset and
approach, followed by actual cases to underpin and provide further support and expand the
number of tools in the toolbox. Making optimal use of lessons learned and translating those
into guidelines and actual project proposals for vulnerable areas around the globe. All based
on proven technology and concepts. Tailor made and adjusted to local circumstances.
Climate change induced events come at greater pace and with an increase in intensity and
duration. The negative effects are often highlighted in the news. Not so much or not at all, the
good news about systems which seem to survive and overcome these events without too
much impact or no impact at al.
It’s these systems the “Resilient by Nature“ approach is focusing on. On what can be
learned from nature and how that knowledge and experience can be translated and
transferred into solutions for more vulnerable places elsewhere, apparent less able to cope
with these events.
In order to determine the viability of this approach, a number of systems have been analyzed
and their effectiveness potential assessed. With promising results.
It’s now a matter of stepping up to the next level. Identifying and investigating concrete cases
in other parts of the world where the “Resilient by Nature“ approach and tools can be
implemented. Such as on a number of affected SIDS’s (Vanuatu) and heavily urbanized
areas such as the City of New York or Singapore.