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.

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 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 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 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.

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.

This data release includes information used to support interpretations of relations between precipitation and soil moisture for a U.S. Geological Survey post-fire monitoring array installed near Malibu, CA following the 2007 Canyon fire. The 3 datasets are: 1) a time series of precipitation from three tipping bucket rain gages in individual files (Schmidt_2020_CANVQRG1.csv, Schmidt_2020_CANVQRG2.csv, and Schmidt_2020_CANTPRG3.csv; where RG in file name is abbreviation for rain gage), 2) a time series of a total of 9 soil moisture probes distributed with three soil moisture probes installed at varying depths from 3 individual soil pits in 3 individual files grouped by pit (Schmidt_2020_CANVQSM1.csv, Schmidt_2020_CANVQSM2.csv, and Schmidt_2020_CANVQSM3.csv; where SM in file name is abbreviation for soil moisture), and 3) locational and temporal record information for the instruments including manufacturer and serial number as tabular data (Schmidt_2020_Canyon_Fire_Instrument_info.csv) and a shapefile including location information (Schmidt_2020_instruments.shp) as well as a 4 band raster geospatial data file (Schmidt_2020_CAN_RG_SM.png). The data was generally collected from December 1, 2007 to September 5, 2008. Tipping bucket rain gages recorded 0.2 mm per tip with either an irregular time stamp representing each successive tip (CANVQRG1 and CANTPRG3) or at a regular four-minute interval (CANVQRG2) with all null values, representing no measurable precipitation, removed for clarity. Time-progressive cumulative rainfall is reported. Rain gage “CANVQRG1” was located closest to soil moisture monitoring instruments (“CANVQSM1, “CANVQSM2”, and “CANVQSM3”). Soil moisture probes recorded dimensionless volumetric water content in m^3/m^3 utilizing the dielectric constant of the media using capacitance or frequency domain technology. Probes were placed at three different depths in the soil: 5, 15 and 30 cm below the ground surface. Pit CANVQSM1 located closer to top of ridge, pit CANVQSM2 located mid-slope, and pit CANVQSM3 located downslope closer to the base of the hillslope. Soil moisture measurements were logged at regular time intervals, varying between two or six minutes, with recorded values reported as averages for that two- or six-minute interval. Column headers for soil moisture data denote unique instrument serial number and placement depth below ground surface in centimeters. Data pertaining to instrumental error was removed and entries left as null values. Negative reported values, outside of normal instrument recording range, during dry and likely hot conditions were left unmodified within data sets. All geographic coordinates reported as UTM NAD83 Zone 11N. All times are in Pacific Standard Time set to field laptop with migration forward one hour at 2 am on March 9, 2008.

This data release includes information used to support interpretations of relations between precipitation and soil moisture for a U.S. Geological Survey post-fire monitoring array installed near Malibu, CA following the 2007 Canyon fire. The 3 datasets are: 1) a time series of precipitation from three tipping bucket rain gages in individual files (Schmidt_2020_CANVQRG1.csv, Schmidt_2020_CANVQRG2.csv, and Schmidt_2020_CANTPRG3.csv; where RG in file name is abbreviation for rain gage), 2) a time series of a total of 9 soil moisture probes distributed with three soil moisture probes installed at varying depths from 3 individual soil pits in 3 individual files grouped by pit (Schmidt_2020_CANVQSM1.csv, Schmidt_2020_CANVQSM2.csv, and Schmidt_2020_CANVQSM3.csv; where SM in file name is abbreviation for soil moisture), and 3) locational and temporal record information for the instruments including manufacturer and serial number as tabular data (Schmidt_2020_Canyon_Fire_Instrument_info.csv) and a shapefile including location information (Schmidt_2020_instruments.shp) as well as a 4 band raster geospatial data file (Schmidt_2020_CAN_RG_SM.png). The data was generally collected from December 1, 2007 to September 5, 2008. Tipping bucket rain gages recorded 0.2 mm per tip with either an irregular time stamp representing each successive tip (CANVQRG1 and CANTPRG3) or at a regular four-minute interval (CANVQRG2) with all null values, representing no measurable precipitation, removed for clarity. Time-progressive cumulative rainfall is reported. Rain gage “CANVQRG1” was located closest to soil moisture monitoring instruments (“CANVQSM1, “CANVQSM2”, and “CANVQSM3”). Soil moisture probes recorded dimensionless volumetric water content in m^3/m^3 utilizing the dielectric constant of the media using capacitance or frequency domain technology. Probes were placed at three different depths in the soil: 5, 15 and 30 cm below the ground surface. Pit CANVQSM1 located closer to top of ridge, pit CANVQSM2 located mid-slope, and pit CANVQSM3 located downslope closer to the base of the hillslope. Soil moisture measurements were logged at regular time intervals, varying between two or six minutes, with recorded values reported as averages for that two- or six-minute interval. Column headers for soil moisture data denote unique instrument serial number and placement depth below ground surface in centimeters. Data pertaining to instrumental error was removed and entries left as null values. Negative reported values, outside of normal instrument recording range, during dry and likely hot conditions were left unmodified within data sets. All geographic coordinates reported as UTM NAD83 Zone 11N. All times are in Pacific Standard Time set to field laptop with migration forward one hour at 2 am on March 9, 2008.

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 South Fork fire event that began on or near 2024-06-17. Contents: Shapefiles.zip Zip archive of hazard modeling results. Includes shapefiles for the fire perimeter, stream segments, catchment basins, and outlet points. sfk2024-field-descriptions.txt Descriptions of the shapefile data fields. sfk2024-median-thresholds.csv Table of median rainfall thresholds as calculated over the stream segments and catchment basins. sfk2024-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.