Vulnerability of California Roadways to Post-wildfire Debris Flows

Date: July 17, 2020

Author(s): Mikhail Chester, Rui Li

Abstract

A vulnerability assessment of California roadways to post-wildfire debris flows is developed. The work examines current and future conditions, considering climate change scenarios and how they affect fire risk and precipitation. Results show how post-fire debris flow risks change from today into the future. A discussion is presented on how to prioritize investments considering the criticality of roadways within the broader network.

About the Project

Wildfires and post-fire debris flows have had severe impacts on California’s transportation system recently, and climate forecasts show that these hazards are likely to become more of a concern in the future. Yet our understanding of the vulnerability of transportation systems to wildfires is in its nascent stages, with focus largely on evacuation logistics and characterizing where risks of fire are increasing and which infrastructure are co-located. Wildfire risk is much more complex as post-fire precipitation events create conditions where roadway stormwater management is failed often leaving remote communities disconnected. There is an opportunity to improve our understanding of the vulnerability of transportation systems and associated adaptation strategies to ensure that services continue to be delivered in the face of growing hazards. This problem is not specific to California as wildfires across the Southwest are becoming more problematic.