class presentation on social vulnerability to environmental h

7/29/2019 Class Presentation on social vulnerability to environmental h

1/15

Social Vulnerability to

Environmental Hazards

Dinee Tamang

Roll No: MSD355M.Sc DRM ,1st semester

Susan L. Cutter, Bryan J . Boruff and W. Lynn Shirley of University of South Carolina


2/15

Background

vulnerability to environmental hazards means the potential for loss

three main tenets in vulnerability research

The identification of conditions that make people or places vulnerable toextreme natural events, an exposure model

the assumption that vulnerability is a social condition, a measure of societalresistance or resilience to hazards

the integration of potential exposures and societal resilience with a specific focuson particular places or regions

Vulnerability Paradox


3/15

Factors influencing social Vulnerability

Major factors that influence social vulnerability

Lack of access to resources

Limited access to political power and representation

Soc ial capital, including soc ial networks and connections

Belief and customs

Building stock and age

Frail and physically limited individuals

Type and density of infrastructure and lifeline

Disagreements arise in the selection of specific variables to represent thesebroader concepts


4/15

Factors Influencing Social VulnerabilityHigh status,

Gender

Nonwhite, Non-Anglo

Elderly, Children

Large Spec ial needs population

High density and high value ofcommercial and industrial

developmentEmployment loss

Rural

Urban

Mobile homes

Renters

High Birth rate, Large families,

Single parent households

Rapid Growth

High status

Occupation (Professional or

managerial)Highly educated

Higher density of medical services

Low dependence


5/15

Question ?

Can we empirically define a robust set of variables that capture all thecharacteristics , which allows us to monitor changes in social vulnerabilitygeographically ad over time?


6/15

Objective

County-level soc ioeconomic and demographic data were used toconstruct an index of social vulnerability to environmental hazards, calledthe Social Vulnerability Index (SoVI) for the United States


7/15

Methods

Data Collec ted: Soc ioeconomic data for 1990 for all 3,141 U.S. counties

Data source: U.S. Census (City and County Data Books for 1994 and 1998)

Selection of variables

Spec ific variables characterizing broader dimension of Social Vulnerability (250)

85 raw and computed variables

42 independent variables used in statistical analysis

Use of Factor Analysis: Principal Component Analysis

Total 11 factors were produced to explain variance among all counties

Multicollinearity testing among variables

Computization and normalization of data


8/15


9/15

Methodology

Hazard of Place Model of Vulnerability (Modified from Cutter, (1996)


10/15

SoVI (Social Vulnerability Index) Relative measure of the overall social vulnerability for each country

Analysis Use of additive model to produce SoVI

No a priori assumption about importance of factor

Absence of defensible method for assigning weights

Mapping of SoVI scores based on SD from mean into five categoriesranging from -1 to+1


11/15

Result

SoVI ranges from -9.6 (low vulnerability) to 49.51(high vulnerability) withmean vulnerability score of 1.54 (SD=3.38)

Moderate levels of social vulnerability in all counties

Most vulnerable appear in the southern half of nation stretching from southFlorida to California regions

393 counties( most vulnerable)

Most vulnerable county:

Manhattan Borough, Franscisco County and Bronx County(density of built env)

Kalawao and Hawaii ( elderly, race/ethnicity, poverty)

Benton: High debt to revenue ratio

Least vulnerable country: counties clustered in New England

Yellow Stone National Park (protected status)

Exception: Moore Country (in southern central state)


12/15

Comparative Vulnerability of U.S. Counties Based on the Social Vulnerability Index (SoVI)


13/15

Testing reliability and usefulness of SoVI

Correlation between frequency of presidential disaster dec larations bycounty and SoVI index score

Weak but negative relationship observed( r= - 0.099, s= 0.000)

Average number of presidential disaster declarations per county is 2.4

Average number of presidential disaster declarations among mostvulnerable counties is 1.97

Average number of presidential disaster dec larations among leastvulnerable counties is 2.52

Suggests

not statistically significant

No discernible trend in the relationship between presidential declarations andthe degree of social vulnerability


14/15

Conclusions and Suggestions No consensus within social science community about social vulnerability

and correlates, all factors contribute to vulnerability ,some increase it and

others moderate it Social vulnerability is multidimensional concept that helps to identify those

characteristics and experiences of communities (and individuals) thatenable them to respond to and recover from environmental hazards.

SoVI is not a perfect construct and more refinements are necessary

SoVI can be coupled with hazard event frequency and economic lossdata to further examine those individual factors that are the most importantcontributors to dollar losses.

Examination of how the overall social vulnerability as measured by the SoVIhas changed over time and space.

support specific subsetting of counties, such as coastal or riverine counties,

to ascertain similarities and differences in relative levels of socialvulnerability

The development and integration of soc ial, built environment, and naturalhazard indicators will improve our hazard assessments and justify theselective targeting of communities for mitigation based on good socialscience, not just political whim.


15/15

Thank you

class presentation on social vulnerability to environmental h

Documents