Climate change and sea level rise are expected to rise
gradually over long periods, whilst the
consequences of their impacts such as Extreme Weather Events (EWE’s) involving
hurricanes and storm surge tend to occur anytime during the hurricane season
and expected to increase in future. Storm surge is highly complex seaborne hazard originating predominantly from
severe weather events such as tropical cyclones (hurricanes), yet not all
hurricanes end with storm surge. This further increase the space of uncertainty.
In principle, although most countries appear to have risk
assessment frameworks or vulnerability assessments in place but understanding
their prominence is often observed lesser. Assessing risk to design the
adaptive and resilient capability to such extreme events have become strategically important not only to
government but also to industries and sectors involved. It is also essential to
understand the factors affecting vulnerability, resilience and adaptive
measurements for re-assessment of existing technology and new findings.
According to Emergency Management Database (EM-DAT), the
international database for reported disasters, every year since 2006-2015 hydrological
disaster (floods) take the majority of share with 177 events followed by
meteorological disasters(cyclones and storms/waves) which is 96 disasters. However, this should be redefined as
hydrological disasters induced by meteorological events because in most cases floods aren’t occur themselves and normally
caused by cyclones or storm surges or extreme rouge waves, heavy downpours
inundating the city with coastal and riverine flooding (CRED report).
Figure 1: Annual
Disaster Review 2016: statistics and trends (Source:
CRED Report , 2016) Year
Coastal assets and infrastructures exposed to ocean dynamics
pose a significant risk to incur high costs for post-storm remedial measures
and impact on future economic development. A globalized approach becomes requisite to interconnect developed and developing
countries in assessing urban and infrastructure risks through innovative
approaches emphasizing adaptation and resilience.
This paper outlines the significance of analyzing the coastal hazards, vulnerability
and equip adaptation and mitigation methods in practice.
2.1 Case Studies
Case studies provide real-life context approach in
understanding the characteristics, root cause, consequences, and solution. Harnessing this approach across
many case studies provides ‘scenario planning’ databases to assess the
peculiarity of surge occurrences and impacts based on the country’s geo-position.
Use of case studies
comparing various geographic locations would be essential to advance the
boundary conditions of the technology and the applications. Such case study
data and information required for future resilience
coastal resilience would also require being included existing policies and
standards, coastal planning, geographical statistics, rehabilitation and
In future, if frameworks were developed
by authorities for advancing storm surge resilience these could also lead to
scenario planning ‘as a collective’ approach.
2.2 Risk Analysis
assess the risk analysis, the flood risk data, storm
surge peak zone map, geo-data, storm
inundation prediction levels, zone maps on property-level and non-property level (i.e. vulnerable area and vulnerable
infrastructure) will be considered. Further, to evaluate vulnerable people and
coastal communities, zone maps, census data by age, disabled,
will be analyzed.
2.3 Data Collection and
data on disaster events needs a wide variety of
sources. Reliable preliminary data is available only in scarce such
as “storm data of National Weather Service”, NOAA etc which is compiled by
county and date. Although the information is
reliable, it is still subject to change as it does not reflect the overall
summation of damage and casualties
turns to be a major limitation. In such situation, where data is unavailable it
is based on the last recordings that are
observed. Although this could further pose underestimation
or overestimation, with the risk underlying from the storm surges still ‘some data’ is better than
3 Risk assessment for
coastal communities and infrastructure
The increase in urban development within coastal zones have
increased the vulnerability and risk of exposure. The dynamic zone of ‘shore
and sea’ can also affect the risk of exposure to storm surge. A single storm
surge event can lead to highly destructive damage to coastal developments
causing central governments to subsidize a region’s economic and social loss
during the remedial stages.
3.1 Hazard and
The first and foremost step in assessing any risk is to
identify the nature of the hazard and the
vulnerability of being exposed. Considering storm surge and hurricanes, three
potential hazards exist which are,
Robust winds bringing infrastructure damage
Coastal flooding from storm surges, inland
flooding from heavy downpours and river/levee over toppings.
In most cases, the vulnerability is addressed through a
generalized framework approach or tool. Vulnerability to hurricane and storm
surge hazards should be addressed individually especially for those developing
and underdeveloped countries. Especially
developing and under-developed countries are the most vulnerable not only with
their limited access to resources but
also because of their limited adaptability to social, technological and
financial aspects. whilst developed countries don’t
face this instead they require diversity in adaptation and focus on individual circumstances.
Hurricane Katrina (2005), Sandy (2012) and Harvey (2017) were the perfect examples
for a developed country to be criticised for its preplanning.
A vulnerability has three-dimensional hazards which are exposure,
resistance, and resilience. Therefore
hazard, exposure to hazard and hazard bearing capability are primary determinants
to be assessed against vulnerability and scope of resilience (Kasperson, 1995).
Cities (Urban Agglomeration)
Asset exposed (in billion US$)
Table 1: Cities,
population, and assets exposed to coastal
3.2 Risk Assessment
It is important to analyze
the risk assessment report as this becomes
fundamental in preparing the disaster risk reduction plan. The risk, in general, can be assessed based on
frequency, conditions, and length of
exposure to the hazard. But in case of climate
change and related weather events, it is always complicated because of the
level of the uncertainty involved, the complexity
of the system and our understanding of risk. These factors increase the
complexity of assessing the risks.
On the other hand, lack of tools such as government or
authorities monitoring and intervention or regulating bodies become static in
addressing the future risks increases the risk. (ref)
3.2.1 Physical index –
Coastal Land Use and Development Risks
Although vulnerability is high is developed, adaptation to
such vulnerabilities is more complex in urban areas because of their closely
packed infrastructures and land use. Most
developed countries whose communities and infrastructure exposed to coastal
hazards have “coastal zoning” method under which the area is classified as
high-risk, moderate risk zones or low-risk zones. However, every event leaves
with some lessons to be learned i.e some counties which are classified as low-risk zones or have
never been exposed storm surges in the past have been hit by storm surges. This
is mainly due to the continuous change in coastal hydrography especially in
recent years, may have led to inundations. This clearly evident that
reassessment of zoning method is required to adopt
from future surges (20). This further implies that the more high/medium-risk
coastal zones are identified the more the demand for new innovative solutions
for storm surge adaptation and mitigation is required.
Land ownership and responsibilities for building houses, new
water supply, and sewage system
infrastructure can involve multiple private investors and also public sector.
Increasing pressures on local authorities to address local population growth
issues and required infrastructure may result in new housing developments
taking place sometimes without the necessary risk analysis in place. This is
becoming less of a factor for new housing as more government-funded environmental mapping and guidance for regions
and areas move online which can be accessed
by such authorities. However, there is still a risk posed to existing housing
built in coastal developments before such environmental mapping
According to National Hurricane Centre (NHC), the physical characteristics of Low
elevation coastal zones (LECZ) i.e. 10 feet above mean sea level or 500m within
coastal proximity areas surrounded by bays, rivers, and estuaries were classified high-risk
3.2.2 Social Index
Increasing population in and around coastal proximity.
Significant population living in temporary homes, tourists accommodated in
mobile homes, recreational homes, vehicles, and
boats were often stranded during emergency evacuations. (to be continued)
3.2.3 Economical index – Insurance Risk
Marsh Insurance brokerage, in their annual report, has outlined that, the insurance industry has
made changes to their claims. The report details that, lessons learned from all
the storm surge events such as Katrina, Sandy
and Ike have brought definite insurance changes and even in the method of
assessing risk. On the other hand, the report has also highlighted computer
catastrophe models whose results were greatly deviated and boasted compared to
actual loss (1)
Although the National Flood Insurance Program (NFIP) cover
the majority of property in high
flood-risk areas, less than 1% house owners not in high-risk zones had flood
insurance and most areas that were flooded weren’t in the high-risk zones.
Therefore, flood insurance wasn’t covered, and disaster aid was provided by
Federal Emergency Management Authority (FEMA).
4 Risk analysis – Gap
in existing Risk mitigation process
4.1 Emergency Evacuation
Planning and execution of emergency evacuations is a major
procedure which consists of the coordinated and cooperative way of responses.
It is not the same approach that is adapted during every emergency and
therefore often subject to be changed and
updated and therefore should remain as an “ongoing” document. A ‘good’
emergency plan should be explanatory on the anticipated hazards and provision
for realistic hazard management. In general countries will have their own
emergency evacuation plan in place, however,
execution is where the gap continues to
Decision making plays an
important role during the declaration of emergency. Some of the past
events have been critiqued for a delayed declaration of emergency which has resulted in the loss of lives and economic loss. During hurricane Katrina, it is
reported that around 25,000 residents were still residing after the evacuation
was officially declared by FEMA. Therefore, it is highly important to make a decision in the quickest possible way.
A modern emergency is
a new approach where emergency management
is dependent on information and communication technology (ICT). Developed countries
like the US are currently focussing on
new technology i.e decision made by ‘expert systems’ in emergency situations.
The system that forecasts the landfall location from hurricanes also provides
information on declaration of emergencies and evacuations. (ref) Although emergency is pre-planned it does
include public involvement who have the least
expertise during emergencies. Therefore these emergency plans being generated
by experts systems or by individuals certainly impose that public awareness and
proper drills are the only way to test and revise the emergency plans.
Finally, an emergency plan for non-evacuees should also be
in place as some people especially disabled or aged might refuse to evacuate
and remain behind. Emergency plans should also be in place for them.
4.2 Lack of Communication
The former 9/11 public Disclosure Project panel members
criticised that “failure in communication and lack of coordination costs lives”
and gave a failing grade for US federal government’s response to Hurricane Katrina.
Public is not a homogenous entity and for that reason
different group of individual require
a different method of
communication. Communication technique should be based on the demography,
community (literacy), etc. In most case,
the communication gap occurs when experts fail to understand their audiences
and try to communicate in technical language whilst common people were looking
for information in simple language without technical jargons. It is best if
communication within experts is classified as internal communications and when
communicating with people addressing as external communications.
Although hurricane watch-warnings, storm surge watch
warnings were currently in practice to alert the coastal communities, businesses
and infrastructures, lack of information are
recognized during almost every single event. E.g. U.S. coastal cities were
observed to be overwhelmed with information which created ambiguity in certain
places while Haiti was with limited information available about the hurricane. This difference puts forth the idea
of rethinking about capacity building in communication depending upon different
countries. It is undeniable that all the countries tries to communicate with early
warnings until before being taken offline. This creates a communication gap and
it is also recommended as a future research scope to focus on having a virtual
backup eliminating communication interruptions
4.3 Emergency Transportation
Transportation is challenging especially during emergency evacuations.
Sometimes the size of storms even limits can damage transport infrastructure
and network disrupting the logistics of resources (food, water, and medical supply) to evacuees and terminating
Figure 1A coastal
road damaged by 20- foot storm surge during Hurricane Ivan (2004) cutting off
evacuation route (Pic Courtesy: Stephen Morton – Getty Images)
network is robust, especially during evacuation and rescue operations. During
the evacuation, community partnership is
vital. As the community includes those
with personal transportation who often evacuate in right time and those
mobility-limited residents await assistance. Again, decision-making plays a
There are times when risk is misinterpreted or
underestimated. E.g. 2016 Louisiana Floods very likely highlighted by the media
because of 2016 summer Olympics or 2016 U.S. Presidential election. The ‘1000 –
year’ flood event occurred in two days and was officially recorded as the
costliest disasters after Hurricane Sandy (2012). The tropical system was
forming to become a hurricane, and because of moisture in the atmosphere, and the slow swirl movement of
storm system lost its tropical storm element and poured into rainfall. As it did not develop further as a tropical storm
and remained lower than a tropical
depression, the rainfall was either underestimated or its severity was
misinterpreted. NOAA’s weather prediction center
called it “an inland sheared tropical depression” which in fact was lower to be
a tropical depression. It reached a record 24+ inch rainfall across various
locations in Louisiana.
On contradict, Hurricane Matthew (October 2016) was
highlighted by national media and people were given enough early warnings
because it gained the status of a ‘named storm’.
Misinterpreted or underestimated risk creates more economic
and societal damage than the one that is
well conceived and analyzed.
The DAMSS framework
will reiterate the procedure of risk assessment and analysis until risk and
underlying is appropriately assessed.
5 Results – Proposed Risk
adaptation factors through damss
5.1 Sustainable drainage
Drainage is an important factor which controls the surface
water especially during inundations from riverine or coastal flooding. It is
these, which reduces the impacts from flooding. National Audit Office (NAO),
England, reports that “half of Britain’s flood defense
systems are either being maintained at minimal-level or deteriorating and
currently 10% of funds have been cut off
excluding one-off emergency funding. This shows even developed countries were
giving less attention to such systems which creates significant impacts.
Another good example was the most efficient pumping system
of New Orleans which had the capacity to drain 300 million gallons of water in
a day was entirely inundated by surge water making the system inoperable
leaving the city flooded for more than two weeks. It was also to be noted that
failure to this system occurred from the submerged
power unit. The New Orleans situation clearly emphasizes the necessity for increased
manual drain holes, the efficient
sustainable draining system should be in place to adapt to such massive risks
likes storm surge. The Japanese G-cans was officially
known as Metropolitan Area Outer Undergrounds Discharge Channel (Refer
Appendix 2) which are addressed as the world’s largest sustainable drainage to
mitigate flooding from typhoons and heavy downpours.
Economically underdeveloped countries cannot invest in
building huge structures to defend coastal hazards. Therefore, economically
efficient investments such as trench drain system could be installed which is
comparatively lower. (ref).
The research will both address the possibilities of having
sustainable drainage systems in developed and developing/under-developed
5.2 Insurance policy
During hurricane Katrina, private insurance industries in
The Bahamas, suffered a significant impact as it was not supported by the State
government. The insurers withdrew from their cover for some of the areas
resulting in homeowners to self-insure or
limiting the premium with exclusions. The consequence also resulted in property
being abandoned, mortgage loss etc. In the USA,
the National Flood Insurance Program (NFIP) covers most properties in flood
risk zones and it is mandatory for the homeowner
to register for this program. Although lessons learned from past events have imposed significant change within the insurance industry, the recent record flooding
from hurricane Harvey, once again proves that this
insurance risk demands an ongoing refinement. The current insurance
policies do not appear to have incorporated with the forecasted future sea
level rise scenario. This means the future insurance policies are subject to be
revised and remains as a temporary solution for the long-term situation.
5.3 Construction industry
Construction is another major industry which requires refinement when it comes to risk
mitigation. Rapid urbanization and industrialization have triggered various impacts, which are now making the task of
adaptation difficult. The increase in urban development within coastal zones
have increased the vulnerability and risk of exposure.
hurricane Katrina, some of the modern engineered infrastructures built to
withstand Category 3 and above hurricanes and their design failure to survive
the catastrophe became a noticeable engineering failure. The U.S Army of Corps
engineered levee system, The Louisiana Superdome, i-10 Twin Span Bridge and the
New Orleans pumping station were among those infrastructures.
For industries such as construction,
it is time to change from ‘hard-engineering’ to ‘soft/smart engineering’ rather than investing more in building a seawall and maintaining it throughout its lifespan. Also in most cases, the site for dams or storm surge barriers are most likely to
have been previously utilized in the process of building dams. This concluded
only inferior sites would have been left and dams, sea walls, barriers built
with latest technologies will have less lifespan
than previously built dams (3).
5.4 Multi-agency Approach
Most under-developed or developing countries refuse to
invest and allocate on coastal defense,
refine their coastal flood protection policies annually. E.g. Maputo,
Mozambique’s capital contributes 19-20% for Mozambique’s GDP and yet receives
very less funding support for flood management and disaster risk reduction.
approach should be adopted globally. Compared to hurricane Katrina, Matthew was
well planned with responders in place. Before the landfall of Matthew’s arrival
in the USA, FEMA had its resources
available in their support base to be mobilized anytime. It was reported that
Non-profit group and volunteers were involved during hurricane Matthew. On the
contrary, hurricane Matthew which caused loss of 800 lives in Haiti. This is
not only because Haiti, is underdeveloped
country, various other reasons such as political instability, poor infrastructure
play their part. During the 2010 Haiti earthquake, although aid from various
countries was provided, only minor
portions were channeled through the
government. This type of situations suggests that a globalized multi-agency approach turns to be the only possible
adaptation solution for countries like Haiti.
In most case, where risk is assessed, yet losses occur
because the risk is not mitigated by adopting any of the solutions such as
transferring risk, maintain risk neutrality or improper risk management.
Experts declare that the next step of any risk management is “risk acceptance”
when the impact is from endogenous factors and when risk couldn’t be managed to
transfer. Climate change adaptation or adaptation to EWE such as hurricanes and
storm surges are a non-transferrable risk
and therefore risk loving and risk acceptance should be the next step.
From the past events and lessons learned, although the risk is assessed in earlier stages, decision
making has made greater impacts. “Defence or retreat” becomes the simplest
solution for coastal hazards and sea-borne disasters, and yet becomes complex
when to retreat, how to defend.
With regards to hydrological or meteorological disaster, it
is always an “iceberg illusion” and any purported solution for adaptation
should include the direct and indirect risks involved.
This paper is partially based on the development of DAMSS (Disaster Adaptation and Mitigation for
Storm Surge) framework. Any opinions expressed in this paper are those of
authors and do not necessarily reflect views of any person or organization.