2nd World Bosai Forum (WBF)International Disaster & Risk Conference (IDRC) 2019
9th – 12th November 2019, Sendai, JapanThe state-of-the-art review ofvulnerability indices: With a special
focus on urban flood

Tanaya Sarmah & Sutapa Das
Indian Institute of Technology Kharagpur,
India

Definitions of Vulnerability
Definitions
The characteristics of a person or a group in terms of their capacity to anticipate, cope
with, resist & recover from the impact of a hazard.

References
Blaikie et al (1994)

Refers to a measure of a person or a group’s exposure to the effects of a hazard, including
the degree to which they can recover from the impact of that event.
Refers to the potential for loss of property or life from environmental hazards.

Cutter et al (2000)

Refers to the degree to which a system, sub-system, or system component is likely toexperience harm, due to exposure to a hazard.

Turner et al (2003)

A human condition or process resulting from physical, social, economic, &environmental factors which determine the likelihood & scale of the impact from a given
hazard.

UNDP (2004)

Vulnerability is used as the magnitude of the threat of poverty, measured, before the veilof uncertainty has been lifted.

Calvo & Dercon (2005)

Refers to the state of susceptibility to harm from exposure to stresses associated withenvironmental & social change & from the absence of capacity to adapt.

Adger (2006)

Refers to the degree to which a system is susceptible to, & unable to cope with adverse
effects of climate change, including climate variability & extremes.

Parry et al (2007)

Refers to a function of the character, magnitude, & rate to which a system is exposed.
Refers to the conditions determined by physical, social, economic & environmental
factors or processes which increase the susceptibility of an individual, a community,
assets or systems to the impacts of hazards.
Tanaya Sarmah & Sutapa Das

UNDRR (2016)

The state-of-the-art review of vulnerability indices: with a special focus on urban flood2

Hyogo Framework (2005-2015)
PRIORITIES About WHAT are the risks that
affect DRR
 10-year plan to make the world
safer from hazards
 Endorsed by UN General
Assembly Explains, describes, details thework to be done to reduce disasterlosses GOAL: To reduceo Disaster losses by building theresilience of nations &communities to disasters
o Loss of lives & social, economic& environmental assets whenhazard strikes

Tanaya Sarmah & Sutapa Das#1
Ensure DRR is anational & local
priority with strong
institutional basis for
implementation#2
Identify, assess &monitor disaster risks& enhance early
warning#3
Use knowledge,innovation &education to build aculture of safety &resilience#4
Reduce the underlying
risk factors#5Strengthen disaster
preparedness for
effective response

The state-of-the-art review of vulnerability indices: with a special focus on urban flood

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Sendai Framework (2015-2030)
 About HOW to reduce the losses
associated with the risks
 15-year plan to make the world safer
from hazards
 Endorsed by UN General Assembly Role of all stake holders in DRR

 GOAL: To reduce

PRIORITIES#1Understanding
disaster risk

#2
Strengthening
disaster risk
governance to manage
disaster risk
#4
Enhancing disaster
preparedness for
effective response & to
“Build Back Better” inrecovery, rehabilitation& reconstructiono Disaster risk & losses in lives,#3
livelihoods & healthInvesting in DRR foro Disaster risk & losses in theresilience
economic, physical, social, cultural& environmental assets of persons,businesses, communities &countries(To increase) TARGETS: (To reduce)o No. of countries with DRR strategieso Global disaster mortalityo International co-operationo No. of affected people globallyo Availability of & access to multi-hazard
o Direct disaster economic loss
early warning systems
o Disaster damage to CI & disruption ofbasic services
Tanaya Sarmah & Sutapa Das

The state-of-the-art review of vulnerability indices: with a special focus on urban flood

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Types of Vulnerability
 No universal definition – can be broken into Social, Physical, Environmental &Economic

Tanaya Sarmah & Sutapa Das

SocialPhysicalEnvironmental

Economic

The state-of-the-art review of vulnerability indices: with a special focus on urban flood5

Systematic Review
 OBJECTIVE QUESTIONS
o What are the Vulnerability Indices (VIs) in the last 20 years (1998-2018)?
o Can VIs be classified into different types — social, physical, environmental &economic? Are there other types?
o What indicators are most used for each VI type?
o What techniques are most used for developing a VI?
o Are there any VIs which is composed of more than one type?

 DATABASEooooo

KEYWORD SEARCHSCOPUSWeb of Science
Google Scholar
Science DirectTaylor & Francis Online

 Initially over 500 papers – duplicates, coastal floods, riverine floods excluded 64 research papers – 38 journal articles, 21 conference proceedings, 5 technical reports
Tanaya Sarmah & Sutapa Das

The state-of-the-art review of vulnerability indices: with a special focus on urban flood

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Proposed Methodology

Included

Eligibility

Screening

Identification(as per PRISMA 2009)
e-database searching(n = 524)

bibliography, citations & other sources(n = 32)

Records after duplicates & theses removed(n = 220)
Records screened(n = 220)

Records excluded due tounrelated focus on VIs (n = 83)

Full-text articles assessed for eligibility(n = 137)

Full-text articles excluded, forriverine & costal floods (n = 73)

Studies included in synthesis(n = 64)

PRISMA = Preferred Reporting
Items for Systematic Reviews &Meta-Analyses

Tanaya Sarmah & Sutapa Das

The state-of-the-art review of vulnerability indices: with a special focus on urban flood

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Types of Vulnerability IndicesParameters

SocialPhysicalEnvironmental

Economic

No. of references

17092810Focus area

Population

Property

Environmental
degradation

Monetarytransaction

Type of loss

Direct tangible,
Indirecttangible,Intangible

Direct tangible

Indirect tangible,
Intangible

Direct tangible,
Indirecttangible

 Types of urban flood impacts as per Hammond et al (2015) –Direct tangible, Indirect tangible & Intangible All three impacts adequately represented by Social & Physical VIs

Tanaya Sarmah & Sutapa Das

The state-of-the-art review of vulnerability indices: with a special focus on urban flood

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Social Vulnerability Index Demographic characteristics, socioeconomic status & health –important factors
 Risk perception and coping capacity
not adequately represented
 Depends highly upon context
 Methods –o Relative scoring (9 out of
17~53%)o Principal Component Analysis(18%)
o Factor analysis (18%)
o Balanced weighted average (11%)
Tanaya Sarmah & Sutapa Das

Factors most utilised:
Education: loss of learningdays, mode of travel to schooletc. (15 out of 17)
Health: no. of deaths, type ofwater-borne diseases, etc. (13out of 17)
Income: loss of man days,
monetary loss per day, etc. (12out of 17)
Others: (average 5 out of 17)
o Dependency on public infrastructure(drinking water, sanitation, wastedisposal)
o Special conditions during UF (safety
during UF, power-cuts, etc.)o Household information (no. of heads,years of stay, etc.)

The state-of-the-art review of vulnerability indices: with a special focus on urban flood9

Physical Vulnerability Index
 Physical — focus buildings (8 out of 9) Site condition (slope, soil, etc.),building typology, building
parameters – important factors
 Direct effect of flood water onbuildings not adequately represented
 Depends highly upon depth &duration of flood water Methods –Flood depth:(6 out of 9)
Flood duration:(2 out of 9)
Flood damage inmonetary terms:(7 out of 9)
Others: (1 out of 9)o Depth-damage curve (4 out of9~44%)o Hazus-MH loss estimation (5 outof 9~56%)
Tanaya Sarmah & Sutapa Das

Factors most utilised:o Building components (buildingmaterial, presence of basement,presence of open storey, year
built/ age, etc.)

The state-of-the-art review of vulnerability indices: with a special focus on urban flood

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Proposed Index Need for an index which is able to describe thevulnerability of an urban area in terms of its populationand property
 Proposed for a social + physical index
 Social – Human VI or HVI
 Physical – Building (private or public) VI or BVI
 As the city is built by the people and for thepeople both human and building vulnerability
are critical
Case study area: Guwahati, capital of Assam state in North-East India
 The region is sole connection between NE states andmainland – therefore strategically important Prone to riverine flood, earthquake and landslide —therefore disaster hotspot
 Growing population took over the hillocks and wetlands— soil erosion, choked natural drainage, landfill ofnatural basin
Tanaya Sarmah & Sutapa Das

Location map of Guwahati

The state-of-the-art review of vulnerability indices: with a special focus on urban flood

11Human Vulnerability Index (HVI) –Existing Condition

Disruption of livelihood –Hard for daily wage earner

Disruption to education

Impact on commerce

Impact on public health

Tanaya Sarmah & Sutapa Das

The state-of-the-art review of vulnerability indices: with a special focus on urban flood

12Human Vulnerability Index (HVI) Wards of Guwahati were graded in terms of human vulnerability using a 5point scale (very high to very low) Questionnaire survey was modified from HDI
 Sample size = 1023 residents
 Questionnaire consisted of 31 indicators (parameters) grouped under 6constructs:o Householdo Educationo Healtho Income
o Dependency on public infrastructure (drinking water, sanitation, wastedisposal)
o Some special conditions during urban flood

Tanaya Sarmah & Sutapa Das

The state-of-the-art review of vulnerability indices: with a special focus on urban flood

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Human Vulnerability Index (HVI)
HVI map of case study areaof Guwahati

Tanaya Sarmah & Sutapa Das

The state-of-the-art review of vulnerability indices: with a special focus on urban flood14

Building Vulnerability Index (BVI) –Building Typologies

RC frame structure(burnt brick in cement mortar infill wallswith RC slab roof)

Ekra house(wooden frame with mud/ cement plastered Ekra orelephant grass infill walls and CGI sheet hipped roof)

Confined masonry structure(Columns and burnt bricks in cement mortar as
infill walls and CGI sheet pitched roof withwooden under-structure
Tanaya Sarmah & Sutapa Das

The state-of-the-art review of vulnerability indices: with a special focus on urban flood

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Building Vulnerability Index (BVI) –Existing Condition

Building settled till sill level underaction of flood water

Building basement filled with mud
brought by flood water

Building’s settled till plinth level under action of flood water
Tanaya Sarmah & Sutapa Das

The state-of-the-art review of vulnerability indices: with a special focus on urban flood

16Building Vulnerability Index (BVI) Buildings – Critical Infrastructure (CIs)
 CIs of Guwahati were graded in terms of building vulnerability using a 5-point
scale (very high to very low) Questionnaire survey was modified from RVS for seismic hazard by US-FEMA Questionnaire consisted of 20 indicators (parameters) Sample types
o RC Frame structureo Confined Masonry structureo Ekra houses

 A newest approach to urban flood assessment
 A quick & comprehensive method for practitioners and local authorities

Tanaya Sarmah & Sutapa Das

The state-of-the-art review of vulnerability indices: with a special focus on urban flood17

Conclusions
 Vulnerability measurement is social, physical, environmental & economic
 Systematic review suggests that there is no index which can assess thevulnerability of human & buildings together, in an urban flood prone area
 Cities are built of both buildings (physical) and human (social). Thus, HVI and
BVI will give a holistic picture This can provide a measurement tool with an enhanced range and sensitivity forassessing comprehensive vulnerability
 Scale will be useful in showing which areas are more vulnerable for thepopulation and buildings together
 This information could be used for prioritisation and fund allocation
 Advantageous for decision makers as it helps to set the framework for evaluating
specific goals, & helps to monitor capability over a longer term Methodology usable for Tier-II Indian cities such as Ahmedabad, Jamshedpur,Srinagar, Surat etc. which are prone to urban flood
 Similar method can be applied to other types of vulnerability measurement, incombinations, to derive specific findings
Tanaya Sarmah & Sutapa Das

The state-of-the-art review of vulnerability indices: with a special focus on urban flood18Thank Youtanayasarmah90@gmail.com
sutapa.d@gmail.com