Nicolas W. Mathews Ben A. Leshchinsky David Sousa Maryn Sanders Peyton Presler Josh J. Roering 20240212 vector digital data, tabular digital data, and geotechnical soil characterization https://doi.org/10.5066/P1QHQHAM This data release contains (1) geotechnical reports describing colluvium strength and grain size distribution, (2) hydrological monitoring data (rainfall and soil volumetric water content), and (3) shapefiles of mapped landslides from 1996 and 2021 that occurred in the Columbia River Gorge, Oregon. The geotechnical reports describe test results from a sieve and hydrometer analysis (ASTM D422) to characterize the grain size distribution and from consolidated drained direct shear tests (ASTM D3080) to characterize soil shear strength. Hydrological data includes a time history of rainfall and volumetric water content from a monitoring station in the Columbia River Gorge, spanning 10/28/2022 to 2/13/2023. The mapped landslide shapefiles represent shallow landslide source areas, assumed to have failed during storms in 1996 and 2021. These data were used to parameterize a physics-based slope stability model to assess postfire landslide potential in the Columbia River Gorge, Oregon. They were used in the following paper: Mathews, N.W., Mirus, B.B., Leshchinsky, B.A., Rengers, F.K., Kean, J.W., Sousa, D., Burns, W.J., Roering, J.J., in review. Assessing postfire landslide initiation potential and recovery in the Pacific Northwest, USA using a three-dimensional physics-based model. Engineering Geology. 19960208 20230213 observed Complete None planned -122.13970 -121.91650 45.64530 45.56779 Extent of data for Eagle Creek burn area None landslide hydrology geotechnical shear strength USGS Metadata Identifier USGS:65ca828fd34ef4b119cb330d None. Please see 'Distribution Info' for details. None. Users are advised to read the dataset's metadata thoroughly to understand appropriate use and data limitations. Nicolas W Mathews U.S. Geological Survey Research Civil Engineer mailing address

Mail Stop MS 966, 1711 Illinois St

Golden CO 80401 US 303-273-8500 nmathews@usgs.gov Nicolas W. Mathews Benjamin B. Mirus Ben A. Leshchinsky Francis K. Rengers Jason W. Kean David Sousa William J. Burns Joshua J. Roering 20240801 publication No formal accuracy tests were performed. Data follows all logical consistencies. Data contains information tied to certain time periods, as described in the abstract. Data is considered complete within the limitations discussed in the following paper: Mathews, N.W., Mirus, B.B., Leshchinsky, B.A., Rengers, F.K., Kean, J.W., Sousa, D., Burns, W.J., Roering, J.J., in review. Assessing postfire landslide initiation potential and recovery in the Pacific Northwest, USA using a three-dimensional physics-based model. Engineering Geology. Horizontal scale is acceptable for scale of mapping. Vertical accuracy is not needed for this data release. For the geotechnical data, soil cores spanning 30-45 cm depth were collected using an auger and soil sampler and a sample of near-surface soil (0-15 cm depth) was collected in a resealable bag. Shear strength was determined for soil cores from two locations using consolidated drained direct shear tests (ASTM D3080) and a grain size distribution for the near-surface soil was determined using a sieve and hydrometer analysis ( ASTM D422). Direct shear tests were performed for soil cores from two adjacent stations: S1 (45.5678888889, -122.1334611111) and S2 (45.5677861111, -122.1337277778). The sieve and hydrometer test was performed on soil from station S2. The rainfall and volumetric water content time series was collected by monitoring station S2, which was installed in October 2022. Landslide mapping was performed by comparing pre- and post-event orthoimagery. 20220201 Nicolas W Mathews U.S. Geological Survey Research Civil Engineer mailing address

Mail Stop MS 966, 1711 Illinois St

Golden CO 80401 US 303-273-8500 nmathews@usgs.gov Vector G-polygon 23 Lambert Conformal Conic 46.0 44.3333333333333 -120.5 0.0 2500000.0 0.0 coordinate pair 0.6096 0.6096 meters North_American_Datum_1983 GRS 1980 6378137.0 298.257222101 S2_monitoring_station_20221028_to_20230213.csv Comma Separated Value (CSV) file containing data. Producer Defined DateTime Date and time of recording Producer Defined Date and time in format: mm/dd/yyyy hh:mm Rain_mm Rainfall in mm Producer Defined 0.0 4.1 mm VWC_75cm Volumetric water content in m^3/m^3 Producer Defined 0.2038 0.3466 m^3/m^3 landslide_initiation_1996.shp Attribute Table Table containing attribute information associated with the data set. Producer Defined FID Internal feature number. ESRI Sequential unique whole numbers that are automatically generated. Shape Feature geometry. ESRI Coordinates defining the features. area Area of polygon in m^2 Producer Defined 561.482391179 10295.9304922 m^2 landslide_initiation_2021.shp Attribute Table Table containing attribute information associated with the data set. Producer Defined FID Internal feature number. ESRI Sequential unique whole numbers that are automatically generated. Shape Feature geometry. ESRI Coordinates defining the features. area Area of polygon in m^2 Producer Defined 52.5574349977 12168.0361722 m^2 GS ScienceBase U.S. Geological Survey mailing address

Denver Federal Center, Building 810, Mail Stop 302

Denver CO 80225 United States 303-273-8500 sciencebase@usgs.gov Unless otherwise stated, all data, metadata and related materials are considered to satisfy the quality standards relative to the purpose for which the data were collected. Although these data and associated metadata have been reviewed for accuracy and completeness and approved for release by the U.S. Geological Survey (USGS), no warranty expressed or implied is made regarding the display or utility of the data for other purposes, nor on all computer systems, nor shall the act of distribution constitute any such warranty. Digital Data https://doi.org/10.5066/P1QHQHAM None 20251119 GHSC Data Steward U.S. Geological Survey, Geologic Hazards Science Center Open Data Policy coordinator mailing and physical

1711 Illinois Street

Golden CO 80401 United States 303-273-8500 ghsc_metadata@usgs.gov FGDC Biological Data Profile of the Content Standard for Digital Geospatial Metadata FGDC-STD-001.1-1999