Evaluating Post-Wildfire Flood Impacts on Transportation Infrastructure for Mitigation Planning

Wildfires have seen a sharp increase in severity and frequency due to changes in climate, especially in the Southwestern U.S., where prevailing conditions of arid climate such as heat waves and droughts can have a dramatic effect on the risk of fire. This study investigated the impacts of post-wildfire floods on transportation infrastructure. Drainages and bridges were specifically targeted as they are especially vulnerable to fire-related damage, whether directly from fire heat or from subsequent flash flooding that results from fire-induced changes to the watershed. The specific objectives of this study were to: (1) identify post-wildfire flash flood impacts as well as risk mitigation and rehabilitation alternatives for transportation infrastructure, (2) evaluate the sensitivity of a hydrology model to site-specific input data and identify transportation infrastructure components at risk of inundation, and (3) develop a decision-support approach for prioritizing and selecting mitigation and rehabilitation options. In response to these objectives, we developed a modeling framework which integrates pre- and post-wildfire rainfall-runoff modeling and floodplain mapping under different climate and burn severity scenarios. Results from a case study analyzed using the model showed that preventing partial or complete blockage of the culverts will preclude roadway inundation under different climate and burn severity scenarios. Thus, the resulting modeling framework can be used as a screening tool for identifying potential problem areas and deciding where to focus further analyses on failure mechanisms, damage assessment, risk mitigation alternatives, and resource allocation. Finally, the proposed decision-making approach explores a wildfire vulnerability assessment process for transportation infrastructure and provides suggestions, resources, and examples for prioritizing infrastructure components and selecting mitigation and rehabilitation measures while considering asset criticality and other characteristics.


  • English

Media Info

  • Media Type: Digital/other
  • Edition: Final Report
  • Features: Appendices; Figures; Maps; Photos; References; Tables;
  • Pagination: 90p

Subject/Index Terms

Filing Info

  • Accession Number: 01728510
  • Record Type: Publication
  • Report/Paper Numbers: SPTC15.1-50-F
  • Contract Numbers: DTRT13-G-UTC36
  • Created Date: Jan 28 2020 9:46AM