Post-Wildfire Debris-Flow Hazard Assessment (PWFDF) Collection

Wildfire can substantially alter the hydrologic response of watersheds to rainfall, and debris-flow activity is among the most destructive consequences of these events. To assist federal, state, and local agencies in planning for postfire hazards, the U.S. Geological Survey conducts debris-flow hazard assessments for recent wildfires. This collection contains the results of those assessments since 2025. Each child item holds the results for a given version of a hazard assessment. The data map the likelihood and potential volume of debris flows across the burn area for a series of design rainstorms. The data also include estimates of the rainfall rates required to trigger debris flows. Assessment results are generally representative of the conditions immediately after the fire; however, additional versions of the hazard assessment are available for some fires. These additional versions may represent preliminary assessments before the fire is fully contained and/or a reassessment of the hazard after one or more years of postfire vegetation recovery. The files, data fields, and metadata included in each assessment strictly conform to the PWFDF Data Specification. You can find archived versions of all current and historical versions of the data specification here: https://ghsc.code-pages.usgs.gov/lhp/ocelote/data-spec/archive/index Collected hazard assessments are typically produced via the Landslide Hazards Program's ocelote codebase. The source code for the codebase is available here: https://code.usgs.gov/ghsc/lhp/ocelote