Service Description: When considering natural hazards, vulnerability generally refers to susceptibility or potential for experiencing the harmful impacts of a hazard event. The foundation of vulnerability analysis, a hazards assessment, generally focuses on a community’s exposure to hazard agents such as floods, surge, wave action, or winds.
Social vulnerability (SV) is defined as ‘‘the characteristics of a person or group in terms of their capacity to anticipate, cope with, resist and recover from the impacts of a natural hazard.’’ Overall Social Vulnerability is determined by combining childcare, eldercare, transportation, shelter, and civic capacity needs factors.
While many factors may be important to understand variability in populations’ abilities to prepare and recover from disasters, a limited number have been selected from readily available data sources such as the U. S. Census and American Community Survey (ACS).
Census and associated data arc collected and aggregated to several census geographies from which measures of the aforementioned factors can be drawn. Most applicable are those drawn from the block group, tract, and county levels.
Service ItemId: ac7a60ef1c5d4426ae72449d12cc7b7c
Has Versioned Data: false
Max Record Count: 2000
Supported query Formats: JSON
Supports applyEdits with GlobalIds: True
Supports Shared Templates: False
All Layers and Tables
Layers:
Description: SVI Metadata
When considering natural hazards, vulnerability generally refers to susceptibility or potential for experiencing the harmful impacts of a hazard event. The foundation of vulnerability analysis, a hazards assessment, generally focuses on a community’s exposure to hazard agents such as floods, surge, wave action, or winds.
Social vulnerability (SV) is defined as ‘‘the characteristics of a person or group in terms of their capacity to anticipate, cope with, resist and recover from the impacts of a natural hazard.’’ Overall Social Vulnerability is determined by combining childcare, eldercare, transportation, shelter, and civic capacity needs factors. Factor county quintile is determined from statewide percentile score.
Field Descriptions
- POPe – estimate of population
- HHe – estimate of households
- VEHe - estimate of vehicles
- SVI - Composite Social Vulnerability Index
- CHILDCARE - Childcare needs
- ELDERCARE - Eldercare needs
- TRANSNEED - Transportation needs
- SHELTNEED - Shelter needs
- CIVICCAP - Civic capacity needs
- CHILDCARE
- CHILD – Children under 5 years population
- SPHWC – Single parent households
- ELDERCARE
- ELDERHH – Elder households
- ELDERHHPV – Elder households in poverty
- TRANSNEED
- PTD – Public transportation dependent households
- HUNOVEL – Housing units with no vehicle
- SHELTNEED
- VACHU – Vacant housing units
- RENTER – Renter households
- NONWHITE – Nonwhite population
- GQ – Population in group quarters
- YEAR20 – Housing units older than 20 years
- MOBILE - Mobile home housing units
- POPV - Population in poverty
- CIVICCAP HUNOTEL – Housing units with no telephone
- NOHS – No high school diploma population
- UNEMP – Unemployed civilian workforce population 16 years plus
- SPENW – Speak English poorly or not at all population
- OTHER FACTORS (Not included in SVI calculation)
- RENTBURDN – Rent burdened households (more than 30% of monthly income spent on rent)
- NOINTNET – No broadband Internet access households
- MEDHVAL – Median home value
All factor fields use following naming codes:
- e - estimate from ACS 5-year averages
- i - index calculated as percent of table universe
- z - statewide standard score
- p - statewide percentile score
- q - county quintile
- c – quintile by USDA commerce zone
Example index field names:
- CHILDe – estimate of CHILD population
- CHILDi – index calculated from proportion of CHILD in total population
- CHILDz – z-score of CHILD
- CHILDp – statewide percentile rank
- CHILDq – county quintile
SVI Calculation Steps
1. ACS data downloaded (R script)
a. 5-year estimate data for 1st order indices,
b. Tables and fields identified and selected by county, tract, and block group,
c. Fields for each first order estimate (e)and table universe assembled to CSV file,
2. CSV imported to SQL Server database (SQL query),
a. Index (i) calculated as percentage), z-score (z), statewide percentile rank (p) calculated,
b. Quintiles (q) calculated by ranking percentiles within county,
c. For some years, quintiles (c) by commerce zone (USDA) also calculated,
d. 2nd order indices calculated as mean percentile rank and grouped by county quintile,
e. 3rd order index calculated as mean of 2nd order indices and grouped by county quintile.
Copyright Text: Hazards Reduction & Recovery Center, Texas A&M University
Spatial Reference: 102100 (3857)
Initial Extent:
XMin: -10735945.1609579
YMin: 3370150.28342979
XMax: -10555623.0039995
YMax: 3522680.85347349
Spatial Reference: 102100 (3857)
Full Extent:
XMin: -11938992.9087689
YMin: 2921685.50620193
XMax: -10388472.4278207
YMax: 4398356.74799306
Spatial Reference: 102100 (3857)
Units: esriMeters
Child Resources:
Replicas
Info
Supported Operations:
Query
ConvertFormat
Get Estimates
Create Replica
Synchronize Replica
Unregister Replica