This data release is a geospatial record of flooding and debris-flow activity following the 2020 Dolan Fire along the central California coast. The postfire hydrologic responses documented here (“Inventory.csv”) are associated with a January 27, 2021, atmospheric river storm that hosted a narrow cold-frontal rain band, which produced intense rainfall over the burned area. Each entry in this record indicates whether no erosion, flooding activity, or debris-flow activity along a given channel reach was apparent in satellite-based imagery and/or during field-based mapping. The “README.txt” file describes the fields for all of the datasets. The “ProcessSteps.txt” file outlines how the data were collected. Additional details and analysis of this dataset are provided in Cavagnaro and others (2025). Reference Cited: Cavagnaro, D.B., McCoy, S.W., Thomas, M.A., Kostelnik, J., and Lindsay, D.N., 2025, Improved prediction of postfire debris flows through rainfall anomaly maps: Geophysical Research Letters, https://doi.org/10.1029/2025GL114791.

This data release supports the analysis of the recurrence interval of post-fire debris-flow generating rainfall in the southwestern United States. We define the recurrence interval of the peak 15-, 30-, and 60-minute rainfall intensities for 316 observations of post-fire debris-flow occurrence in 18 burn areas, 5 U.S. states, and 7 climate types (as defined by Beck, H. E., Zimmermann, N. E., McVicar, T. R., Vergopolan, N., Berg, A., & Wood, E. F. (2018). Present and future Köppen-Geiger climate classification maps at 1-km resolution. Scientific Data, 5(1), 180214. doi:10.1038/sdata.2018.214).

This data release is a field-verified inventory of postfire hydrologic response for the 2020 CZU Lightning Complex, River Fire, Camel Fire, and Dolan Fire following a 26-29 January 2021 atmospheric river storm sequence. Postfire hydrologic response types include a) no response, b) minor response, and c) major response. A “minor” response was deemed capable of impairing infrastructure functioning (e.g., deposition or erosion along a road that could be regraded by mechanized earth-moving equipment within a matter of hours) or causing minor bodily injury (e.g., abrasions, sprains, or broken bones). A “major” response was deemed capable of causing sustained infrastructure impairment (e.g., damage to roads requiring weeks or more of emergency repair efforts or residential structures made uninhabitable) or serious bodily injury (e.g., protracted disfigurement or death). The README.txt file describes the data fields for the “Inventory.csv” file. Fields with value “-9999” indicate that data are not available or do not exist.

This data release includes time-series data from two monitoring stations in a small drainage basin burned in the 2014 Silverado Fire, Orange County, California. One station (upper station) is located in the headwaters of the study area (33 45’39.10”N, 117 35’17.48”W, WGS84). The other station (lower station) is located at the outlet of the study area (33 45’04.61”N, 117 35’12.54”W). The data were collected between November 15, 2014 and January 14, 2016. The data include continuous 1-minute time series of rainfall and soil water content recorded at the both stations and intermittent (during rain storms) 50-Hz time series of flow-induced ground vibrations recorded by geophones at the lower station. The soil water content measurements were made at 2 depths below the ground surface (5 and 10 cm) between 2014-11-15 and 2015-04-24, and 4 depths below the ground surface (5, 10, 15, and 20 cm) between 2015-04-24 and 2016-01-14. The ground vibrations were measured by two 4.5 Hz vertical axis geophones (Geospace SNG 11D/PC902/OPEN-30m) located approximately 3 m from the channel bank and separated by 11.8 m in the streamwise direction. Details of this study are described in the journal article: McGuire, L.A., Rengers, F.K., Kean, J.W., Staley, D.M., and Mirus B.B., (2017), Incorporating spatially heterogeneous infiltration capacity into hydrologic models with applications for simulating post-wildfire debris flow initiation, Hydrologic Processes.

This data release includes time-series data from a monitoring site located in a small drainage basin in the Arroyo Seco watershed in Los Angeles County, CA, USA (N3788964 E389956, UTM Zone 11, NAD83). The site was established after the 2009 Station Fire and recorded a series debris flows in the first winter after the fire. The data include three types of time-series: (1) 1-minute time series of rainfall, soil water content, channel bed pore pressure and temperature, and flow stage recorded by radar and laser distance meters (ArroyoSecoContinuous.csv); (2) 10-Hz time series of flow stage recorded by the laser distance meter during rain storms (ArroyoSecoStormLaser.csv), and (3) 2-second time series of rainfall and channel bed pore pressure and temperature during rain storms (ArroyoSecoStormPressureRain.csv). The laser and radar distance meters are suspended above the pore pressure sensor mounted in the bedrock of the channel. The equations for converting the distance measurements into flow stage above the pressure sensor (or stage of the stationary bed surface during times of no flow) are given by the equations Stage_laser (meters) = 2.107 meters – Distance_laser (meters), and Stage_radar (meters) = 2.156 meters – Distance_radar (feet)*0.3048 Details of this study are described in the journal article: Kean, J. W., D. M. Staley, and S. H. Cannon (2011), In situ measurements of post-fire debris flows in southern California: Comparisons of the timing and magnitude of 24 debris-flow events with rainfall and soil moisture conditions, J. Geophys. Res., 116, F04019, doi:10.1029/2011JF002005.

Postfire debris-flow hazard assessment for the Border 2 fire event that began on or near 2025-01-23, version 1.0. The files, data fields, and metadata included in this assessment are described by version 1.0.0 of the PWFDF Data Specification. You can find the specification here: https://doi.org/10.5066/P13KUWCO Wildfire can substantially alter the hydrologic response of watersheds to rainfall, and debris-flow activity is the 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 repository contains the results of those assessments since 2025. 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. 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.

This data release contains numerous comma-separated text files with data summarizing observations in the within and adjacent to the Woodbury Fire, which burned from 8 June to 15 July 2019. In particular, this monitoring data was focused on debris flows in burned and unburned areas. Rainfall data (Wdby_Rainfall.zip) are contained in csv files called Wdby_Rainfall for 3 rain gages named: B2, B6, and Reavis. This is time-series data where the total rainfall is recorded at each timestamp. The location of each rain gage is listed as a latitude/longitude in each file. Data from absolute (i.e. not vented) pressure transducers (Wdby_Pressure.zip), which can be used to constrain the time of passage of a flood or debris flow, are available in csv files called Wdby_Pressure for four drainages (B1, B6, Reavis 1, and Reavis 2). This is time-series data where the measured pressure in kilopascals is recorded at each timestamp. The location of each pressure transducer is listed as a latitude/longitude in each file. Infiltration data are located in the csv file called WoodburyInfiltration.csv. The location of the measurement is listed as a latitude/longitude. Three measurement values are reported at each location: Saturated Hydraulic Conductivity (Ks) [mm/hr], Sorptivity (S) [mm/h^(1/2)], and pressure head (hf) [m]. The date of each measurement and soil burn severity class are also reported at each location, as well as a table explaining the burn-severity numerical class conversion. Particle size analyses using laser diffraction (WoodburyLaserDiffractionSummary.zip) are located in the files called WoodburyLaserDiffractionSummary for the fine fraction (< 2 mm) of hillslope and debris flow Deposits. The diameter of each particle size class is listed in the first column. All subsequent columns begin with the sample name. The value in each row is the percentage of the grain sizes in the size class. Location data for each of these samples is listed in the accompanying data table titled: WoodburyParticleSizeSummary.csv. The particle size data are summarized in the csv files (WoodburyParticleSizeSummary.zip) called WoodburyParticleSizeSummary by debris flow deposits and hillslope samples. These files group the raw data into more useable information. The sample name (Lab ID) is used to identify the Laser Diffraction data. The data columns (Lat) and (Lon) show the latitude and longitude of the sample locations. The total fraction of all the grain sizes, determined by sieving, are listed in three classes (Fraction < 16 mm, Fraction < 4 mm, Fraction < 2 mm). The fine fractions (< 2 mm) are also summarized in the columns (%Sand, %Silt, %Clay), as determined by laser diffraction. The data are identfied as in the burn area using entries of Yes, whereas unburned areas are shown as No, indicating no burn. The median particle size (D50) is listed if the sample collected in the field was representative of the deposit. In some cases, large cobbles and boulders had to be removed from the sample because were much too large to be included in sample bags that were brought back to the lab for analysis. The last column label (Description) contains notes about each sample. Pebble count data (WoodburyPebbleCountsSummary.zip) are available in csv files called WoodburyPebbleCountsSummary for six drainages (U10 Fan, U10 Channel, U22 Channel, B1 Channel, B7 Fan, and U42 Fan). Here U represents unburned, and B represents burned. The data name indicates whether the data come from a deposit located in a channel or a fan. In each file the particle is numbered (Num) and the B-axis measurement of the particle is reported in centimeters. The location of each pebble count is listed as a latitude/longitude in each file. Channel width measurements for 23 channels are saved in unique shapefiles within the file called Channel_Width_Transects.zip. These width measurements were made using Digital Globe imagery from 19 October 2019. The study basins used for the entire study can be found

This table contains measured and modeled postfire debris flow volumes alongside the associated sources for debris flow documentation, locations, and volumes. We conducted a search of scientific literature and news media reports to find documentation of debris flows that may have followed all wildfires greater than 100 square kilometers that occurred between 1984 and 2021 in California. The wildfires listed are all the fires we found that had documented postfire debris flows. Some fires had field-measurements of debris flow volume. Where field-measurements of volume did not exist, we used model data on postfire debris-flow likelihood and volume from U.S. Geological Survey Emergency Assessment of Post-Fire Debris-Flow Hazards Team (see Lineage section in this metadata). In some cases, exact locations (but not volumes) were known, in which case we used modeled volumes for these locations. Where debris flows were documented but not exact locations, we used the volumes from all basins with a probability greater than eighty percent of having postfire debris flows.

This is a dataset of location and photo data for the debris flow deposits measured in the Tadpole Wildfire. The data were collected using the ArcGIS Collector application by multiple individuals. The original data are stored in a geodatabase here, and the geodatabase has the following fields: Latitude (decimal degrees), Longitude (decimal degrees), Elevation (meters), GlobalID (a unique ID), CreationDate, Creator, EditDate, Editor, and Notes. Each point in the geodatabase represents an observation (either a debris flow deposit or a wood measurement), and most points also include associated photos of the deposit/wood. An opensource version of the geodatabase is provided as a shapefile, containing the same fields mentioned above. The photos associated with each point are in a separate folder in this data release, and the file called photo_table.csv contains the GlobalIDs and photo names that correspond to each location in the shapefile.

The data presented in this data release represent observations of postfire debris flows that have been collected from publicly available datasets. Data originate from 13 different countries: the United States, Australia, China, Italy, Greece, Portugal, Spain, the United Kingdom, Austria, Switzerland, Canada, South Korea, and Japan. The data are located in the file called “PFDF_database_sortedbyReference.txt” and a description of each column header can be found in both the file “column_headers.txt” and the metadata file (“Post-fire Debris-Flow Database (Literature Derived).xml”). The observations are derived from areas that have been burned by wildfire and are global in nature. However, this dataset is synthesized from information collected by many different researchers for different purposes, and therefore not all fields are available for each of the observations. Missing information is indicated by the value “-9999” in the ”PFDF_database_sortedbyReference.txt” file. Note that the text file contains special characters and a mix of date-time formats that reflect the original data provided by the authors. The text may not be displayed correctly if it is opened by proprietary software such as Microsoft Excel but will appear correctly when opened in a text editor software.