Figure 1: Different vulnerability assessment parameter based on
previous research
Catastrophic losses in terms of human casualties, property destruction,
economic damages, and loss of public confidence could result from dam
failure in the downstream and floodplain area. Traditionally, when
man-made disasters caused by sabotage or terrorist actions, the risk is
expressed as a function of the likelihood of an initiating event, the
likelihood of system failure, and the consequences associated with the
failure. There are different models for assessing the risk of a variety
of assets such as Sandia series as RAM models for dams (D-RAM), RAMCAP,
Security Vulnerability Assessment (SVA), CARVER + Shock, PHA, RVA, What
If, FMEA, FMECA, MSRAM, SRFT, and KSM. Some of these methods are
qualitative or semi-qualitative, and some of them are quantitative such
as FTA and ETA (Biringer, Matalucci, & O’Connor, 2007; A. Doro-on,
2011; A. M. Doro-on, 2014; Hokstad, Utne, & Vatn, 2012). Some of these
risk approaches are completely qualitative based on causes and
consequences such as What If, PHA, and FMEA. The models such as FMECA or
CARVER + shock emphasize criticality and exposure to the hazard. Some of
the other approaches have selective techniques, but the comprehensive
module is based on probability and consequence analysis, vulnerability
assessment, and finally risk assessment such as RVA. Some of the other
approaches are based on assumed parameters, which are rigid but simply
such as an SRFT method. Another important factor in risk assessment is
attractiveness, which is more comprehensive than exposure to the hazard.
KSM model emphasis on attractiveness and it is developed based on
strategies od Khalid Sheikh Mohamad (the designer of the 11 September
attack). However, the other approach which covers threat analysis, asset
analysis, attractiveness, and vulnerability assessment to achieve the
risk number for each property is SVA. SVA is one of the comprehensive
approaches, which is currently used in different sectors and
infrastructures. One of the advantages of SVA is the flexibility of
techniques that can be used in each part of SVA (Norman, 2016; van
Staalduinen, Khan, & Gadag, 2016).
Dams as one of the superstructures are very important infrastructures of
each country, especially while dams are dominant to the crowded areas to
make the high-potential target for terrorist action (Danso-Amoako,
Scholz, Kalimeris, Yang, & Shao, 2012). For instance, the Mosul dam
which is the largest dam in Iraq became one of the tools of ISIS for
threatening downstream cities during Mosul occupancy in 2016. On the
other hand, dams have several advantages such as supplying water
resources for potable water, agricultural activities, producing
electricity, and controlling floodwaters. Thus, dams make the downstream
area a growing population center inherently. Cities, industries, and
farms start to grow up while environmental resources such as trees and
woods are started to vanish. These factors highlight the vulnerability
assessment and importance of risk analysis for dams especially based on
downstream properties and assets. Several studies have been done in
vulnerability assessment of areas that are under the effects of a flood
caused by dam destruction. Messervey (2007) has created a framework and
discovered modeling technique’s methods for dam destruction. Awal (2008)
studied dam destruction caused by landslide and flyover increasing water
height (Awal, 2008) and other studies described different alternative
signals and decreasing floodwater risk (Persson, 2015).
As it was considered, most of the researches in this field tried to zone
floodwater and the level of flooding in downstream areas caused by
through the dam destruction, by using hydraulic software or crisis
management under natural threats (such as earthquake, floodwater
and…), but there isn’t any research to evaluate the accurate
vulnerability of dam destruction assets based on hydraulic modeling in
collaboration with water flow factors and destruction scenarios,
particularly under man-made threat. Vulnerability assessment on
infrastructures becomes a highlighted and suspected approach from
homeland security agencies and even private sectors, which owned
infrastructures or at least be one of the stockholders of that
infrastructures. Vulnerability assessment is a part of risk assessment,
which shows the dam or any investigated infrastructure how vulnerable to
the identified threat. So, the vulnerability of infrastructure could be
separated into three categories, which show the enhancement of three
generations of assessment. In the first generation which is clear from
early models such as FMEA, CORVER, RVA, etc.; the inherent properties of
an asset become the main nutrition for assessment of vulnerability or
even the risk assessment of the asset. In the next generation while the
KSM method or SRFT considered the attractiveness and exposure to the
hazard as the other main criterion of vulnerability, which was mentioned
by Kröger and Zio (2011) too, besides asset property according to the
vulnerability and risk analysis (Norman, 2016). Finally, the third
generation is a triangulated approach based on asset property,
attractiveness and dependencies, and interdependencies following the
network of properties. Model-Based Risk Assessment (MBRA) is one of the
integrated models developed by Lewis and Al Mannai in 2008 under
third-generation (Mannai, 2008). The security Vulnerability Assessment
(SVA) approach also considered attractiveness beside the criticality of
properties. However, there is a necessity for a more scientific approach
especially on behalf of hydraulic characteristics of flood and
interaction between flood and downstream properties in the floodplain
area while the destructive action is succeeded.
So, based on the latest vulnerability assessment generation a new hybrid
approach should be developed that considers the vulnerability of the
dam’s downstream area. Thus, this research aims to modify an integrated
hybrid model to analyze the vulnerability of dam’s downstream assets due
to man-made succeeded adversary threats to provide risk analysis and
management and plan for protection or mitigation of the high-risk area.
Figure 2 is showing the theoretical framework of this approach.