This data release includes time-series data from a monitoring site located in a small (0.12 km2) drainage basin in the Las Lomas watershed in Los Angeles County, CA, USA. The site was established after the 2016 Fish Fire and recorded a series debris flows in the first winter after the fire. The station is located along the channel at the outlet of the study area (34 9’18.50”N, 117 56’41.33”W, WGS84). The data were collected between November 15, 2016 and February 23, 2017. The data include two types of time series: (1) continuous 1-minute time series of rainfall and flow stage recorded by a laser distance meter suspended over the channel (LasLomasContinuous.csv), and (2) 50-Hz time series of flow stage and flow-induced ground vibrations recorded by two geophones (LasLomasStorm.csv). The continuous file contains brief data gaps when the station was serviced, at which time the record of cumulative rainfall was reset to zero. The ground vibrations were measured by two 4.5 Hz vertical axis geophones (Geospace SNG 11D/PC902/OPEN-30m) located approximately 2 m from the channel bank. One geophone was located 6.4 m upstream from the laser distance meter. The second geophone was located 7.6 m downstream of the geophone. The geophone data is recorded in millivolts and the geophone constant is 32 Volts/(m/s). The equation for converting the laser distance measurements into flow stage above the bedrock in the channel is: Stage_laser (meters) = 4.320 meters – Distance_laser (millimeters) /1000. Time stamps are in Coordinated Universal Time (UTC). Details of this study are described in the journal article: Tang, H., McGuire, L.A., F.K. Rengers, Kean, J. W., Staley, D.M., and Smith, J.B. (2018), Evolution of debris flow initation mechanisms and sediment sources during a series of post-wildfire rainstorms, J. Geophys. Res., xxx, FYYYYY, doi:10.1029/2018JF004837.

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 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 includes time-series data from two monitoring stations in drainage basins burned in the 2009 Station Fire, Los Angeles County, California. Both stations are located near the upper boundary of their respective watershed and were installed to study the effects of vegetation recovery on hillslope hydrology and debris-flow occurrence. The coordinates of the Arroyo Seco site are 34°14'13.10"N, 118°11'44.72"W. The coordinates for the Dunsmore Canyon hillslope site are 34°15'54.27"N, 118°14'14.41"W. The data include 1-minute time series of rainfall, soil water content, soil temperature, and soil matric potential recorded at two locations at both stations: AS1, AS2, DC1, DC2. The two locations at each site have the primary distinction of being in a non-vegetated location (AS1, DC1) or under vegetated canopy (AS2, DC2). The soil water content measurements were made at 3 depths below the ground surface in each pit (10, 25, and 50 cm). Soil temperature measurements were made in each pit (10 cm). Soil matric potential was measured with a tensiometer at AS1 (50 cm) and DC2 (50 cm), and includes an integrated soil temperature reading from the same instrument. All available data from the time period is included, but occasional lapses exist in the time-series due to various system issues and/or maintenance. The tensiometer data includes erroneous values where in-situ matric potential is outside of the range of the instrument and a data quality flag has been added to aid in the interpretation of these. Details of this study are described in the journal article: Smith, J.B., and J.W. Kean. 2018. Long-term soil-water tension measurements in semiarid environments: a method for automated tensiometer refilling. Vadose Zone J. 17:180070. doi:10.2136/vzj2018.04.0070.

The dataset consists of spatial data showing locations of channel incision points (CIP) and sediment deposition in burned study sites in the Tumut and Tuross Catchment study regions. This dataset includes aerial imagery captured 1-2 years after the 2019/20 bushfires of the study regions from which the locations of CIPs and sediment deposits were determined, and gridded landscape attribute information used to test the spatial association between landscape attributes and CIP density. Refer to the following NRC report 'Post fire debris flow mapping - Coastal IFOA monitoring program - June 2023', which is included in the dataset, for background and further detail.

This Data Release summarizes measurements of hydraulic and physical properties of soils and ash at sites in the area impacted by the 2017 Thomas Fire, USA. Physical properties include dry bulk density, loss on ignition, and saturated soil water content. Hydraulic properties include field-saturated hydraulic conductivity, sorptivity, Green-Ampt wetting front potential, and soil water retention. These measurements provide a foundation to reduce uncertainty of parameters in hydrologic models used to predict water-related hazards, water quality, and water quantity. Note that all methods of data acquisition and processing, column headings, and data annotations are explained in the metadata files.

This Data Release summarizes measurements of hydraulic and physical properties of soils and ash at sites in the area impacted by the 2017 Thomas Fire, USA. Physical properties include dry bulk density, loss on ignition, and saturated soil water content. Hydraulic properties include field-saturated hydraulic conductivity, sorptivity, Green-Ampt wetting front potential, and soil water retention. These measurements provide a foundation to reduce uncertainty of parameters in hydrologic models used to predict water-related hazards, water quality, and water quantity. Note that all methods of data acquisition and processing, column headings, and data annotations are explained in the metadata files.

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 item holds the postfire debris-flow hazard assessment for the Gwen fire event that began on or near 2024-07-24. Contents: Shapefiles.zip Zip archive of hazard modeling results. Includes shapefiles for the fire perimeter, stream segments, catchment basins, and outlet points. gwn2024-field-descriptions.txt Descriptions of the shapefile data fields. gwn2024-median-thresholds.csv Table of median rainfall thresholds as calculated over the stream segments and catchment basins. gwn2024-metadata.txt Auxiliary metadata about the fire event and implementation of the hazard assessment. Methods: The hazard assessment was designed to implement: * The "M1" debris-flow likelihood model of Staley and others (2017) * The "emergency" potential sediment volume model of Gartner and others (2014) * The debris-flow combined hazard classification scheme of Cannon and others (2010) The assessment was produced by USGS personnel running the beta version of the ocelote package. Operational personnel may have also modified stream network delineation and modeling parameters in order to ensure quality. The beta version is represented by the ocelote commits prior to the v1.0.0 release. The ocelote source repository can be found here: https://code.usgs.gov/ghsc/lhp/ocelote References: Cannon, S. H., Gartner, J. E., Rupert, M. G., Michael, J. A., Rea, A. H., and Parrett, C. (2010). Predicting the probability and volume of postwildfire debris flows in the intermountain western United States. Bulletin, 122(1-2), 127-144. Gartner, J. E., Cannon, S. H., and Santi, P. M. (2014). Empirical models for predicting volumes of sediment deposited by debris flows and sediment-laden floods in the transverse ranges of southern California. Engineering Geology, 176, 45-56. Staley, D. M., Negri, J. A., Kean, J. W., Laber, J. L., Tillery, A. C., and Youberg, A. M. (2017). Prediction of spatially explicit rainfall intensity–duration thresholds for post-fire debris-flow generation in the western United States. Geomorphology, 278, 149-162.

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 item holds the postfire debris-flow hazard assessment for the Hill fire event that began on or near 2024-07-16. Contents: Shapefiles.zip Zip archive of hazard modeling results. Includes shapefiles for the fire perimeter, stream segments, catchment basins, and outlet points. hil2024-field-descriptions.txt Descriptions of the shapefile data fields. hil2024-median-thresholds.csv Table of median rainfall thresholds as calculated over the stream segments and catchment basins. hil2024-metadata.txt Auxiliary metadata about the fire event and implementation of the hazard assessment. Methods: The hazard assessment was designed to implement: * The "M1" debris-flow likelihood model of Staley and others (2017) * The "emergency" potential sediment volume model of Gartner and others (2014) * The debris-flow combined hazard classification scheme of Cannon and others (2010) The assessment was produced by USGS personnel running the beta version of the ocelote package. Operational personnel may have also modified stream network delineation and modeling parameters in order to ensure quality. The beta version is represented by the ocelote commits prior to the v1.0.0 release. The ocelote source repository can be found here: https://code.usgs.gov/ghsc/lhp/ocelote References: Cannon, S. H., Gartner, J. E., Rupert, M. G., Michael, J. A., Rea, A. H., and Parrett, C. (2010). Predicting the probability and volume of postwildfire debris flows in the intermountain western United States. Bulletin, 122(1-2), 127-144. Gartner, J. E., Cannon, S. H., and Santi, P. M. (2014). Empirical models for predicting volumes of sediment deposited by debris flows and sediment-laden floods in the transverse ranges of southern California. Engineering Geology, 176, 45-56. Staley, D. M., Negri, J. A., Kean, J. W., Laber, J. L., Tillery, A. C., and Youberg, A. M. (2017). Prediction of spatially explicit rainfall intensity–duration thresholds for post-fire debris-flow generation in the western United States. Geomorphology, 278, 149-162.

These data show model estimates of debris flow likelihood and volume that may be produced by a storm in a recently burned landscape. The scientific methods used by the U.S. Geological Survey Emergency Assessment of Post-Fire Debris-Flow Hazards were changed following 2015, and these shapefiles are a re-release of ten fires that occurred between 1997 and 2015 fires, using the updated methods. These ten fires were re-run to provide estimates of debris flow volumes as post-fire debris flows were documented but no field measurements were published.