Validation of the Indicator-Based Vulnerability Assessment Approach: A Retrospective on the October 2015 South Carolina Flooding

Indicator-based assessments are increasingly being used by transportation organizations throughout the United States in order to screen assets and operations for vulnerabilities to changes in climate. While these assessments provide opportunities to systematically think through questions of vulnerability, deficiencies still exist in the ability of indicators to accurately predict on-the-ground results. The accuracy of indicator-based assessments varies by climate hazard. Predictions of slow, long-term changes in climate are potentially easier to make than indicator-based predictions of extreme events, particularly those with no historical analogue. This analysis sought to improve desk-based vulnerability screening analyses for one of the most difficult hazards, extreme inland precipitation, using the October 2015 flooding in South Carolina as a case study. It used U.S. Department of Transportation’s (DOT) Vulnerability Assessment Scoring Tool (VAST) to retroactively assess the vulnerability of roads and bridges to inland flooding in Richland County, South Carolina. The analysis then compared the results of VAST indicators with on-the-ground impacts in the county. This analysis found some strong indicators for bridges. Location within the FEMA 100- and 500- year floodplains serve as strong indicators of both exposure and sensitivity, and Functional Classification is a good indicator of how quickly bridge service will be restored. Opportunities to improve desk-based vulnerability screening analyses also exist. Incorporating surrounding or “upstream” infrastructure, particularly water control structures, may provide additional accuracy when assessing exposure. Mining institutional knowledge will build insight into sensitivity beyond plain asset attributes, and can shed light on key questions and factors that influence community resilience.

• Supplemental Notes:
  • This paper was sponsored by TRB committee ABR10 Standing Committee on Critical Transportation Infrastructure Protection.
• Authors:
  • Bhat, Cassandra Snow
  • Vargo, Amanda
• Conference:
  • Transportation Research Board 97th Annual Meeting
  • Location: Washington DC, United States
  • Date: 2018-1-7 to 2018-1-11
• Date: 2018

Language

• English

Media Info

• Media Type: Digital/other
• Features: Figures; Maps; References; Tables;
• Pagination: 12p

Subject/Index Terms

• TRT Terms: Accuracy; Asset management; Bridges; Case studies; Disaster preparedness; Disaster resilience; Floods; Hazard analysis; Risk assessment; Validation
• Identifier Terms: South Carolina flood, 2015; U.S. Department of Transportation; Vulnerability Assessment Scoring Tool
• Geographic Terms: Richland County
• Subject Areas: Highways; Planning and Forecasting; Security and Emergencies;

Filing Info

• Accession Number: 01663965
• Record Type: Publication
• Report/Paper Numbers: 18-05599
• Files: TRIS, TRB, ATRI
• Created Date: Mar 22 2018 12:03PM