Kelli W. Baxstrom William H Schulz Mason M Einbund 20240228 remote-sensing image Reston,VA U.S. Geological Survey https://doi.org/10.5066/P9UFKZS8 Hurricane Maria brought intense rainfall and caused widespread landsliding throughout Puerto Rico during September 2017. Previous detailed landslide inventories following the hurricane include Bessette-Kirton et al. (2017, 2019). Here we continue that work with an in-depth look at two areas in San Lorenzo, which is a municipality in the east-central part of the main island. To study a characteristic sample of landslides in San Lorenzo, we mapped all visible landslides in two physiographically diverse areas, but all within the San Lorenzo Formation. We used aerial imagery collected between 9-15 October 2017 (Quantum Spatial, Inc., 2017) to map landslide source and runout areas, and 1-m-resolution pre-event and post-event lidar (U.S. Geological Survey, 2018, 2020) as a digital base map for mapping. Difficulties with using these tools arose when aerial imagery was not correctly georeferenced to the lidar, when cloud cover was present in all images of an area, and in interpreting failure modes using only two-dimensional aerial photos. These difficulties with aerial imagery were partially resolved using the lidar. The map data comprises headscarp points, travel distance lines, source area polygons, and affected area polygons that are provided as point, line, and polygon shapefiles that may be viewed using common geographic information systems. Various characteristics of the landslides and their geomorphic settings are included in attribute tables of the mapped features, and this information is described in the "Attribute Summary" document in the accompanying files. Quantitative attributes (e.g., failure travel distance, failure fall height, watershed contributing area, etc.) were determined using tools available with the ESRI ArcGIS Pro v. 3.0.36056 geographic information system. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government. References Bessette-Kirton, E.K., Cerovski-Darrian, C., Schulz, W.H., Coe, J.A., Kean, J.W., Godt, J.W., Thomas, M.A. and Hughes, K.S., 2019, Landslides triggered by Hurricane Maria: Assessment of an extreme event in Puerto Rico: GSA Today, v. 29, no. 6. Bessette-Kirton, E.K., Coe, J.A., Godt, J.W., Kean, J.W., Rengers, F.K., Schulz, W.H., Baum, R.L., Jones, E.S., and Staley, D.M., 2017, Map data showing concentration of landslides caused by Hurricane Maria in Puerto Rico: U.S. Geological Survey data release, https://doi.org/10.5066/F7JD4VRF. Quantum Spatial, Inc., 2017 FEMA PR Imagery: https://s3amazonaws.com/fema-cap-imagery/Others/Maria (accessed October 2017). U.S. Geological Survey, 2018, USGS NED Original Product Resolution PR Puerto Rico 2015: http://nationalmap.gov/elevation.html (accessed October 2018). U.S. Geological Survey, 2020, USGS NED Original Product Resolution PR Puerto Rico 2015: http://nationalmap.gov/elevation.html (accessed October 2018). This mapping characterizes landslides triggered by Hurricane Maria in San Lorenzo, Puerto Rico. The mapping focused on the San Lorenzo Formation. 20171009 20171015 ground condition Complete None planned -66.02388 -65.93230 18.14626 18.11959 USGS Thesaurus geology geomorphology hydrology USGS Thesaurus Hurricane Maria debris flow landslide inventory landslide mapping hurricane landslide USGS Geologic Hazards Science Center earth science Landslide Hazards Program USGS Metadata Identifier USGS:63124873d34e36012efa1657 GNIS Puerto Rico San Lorenzo None. Please see 'Distribution Info' for details. none Kelli W. Baxstrom US Geological Survey, Geologic Hazards Science Center Geologist mailing and physical

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Golden CO 80401 USA 303-273-8625 kbaxstrom@usgs.gov Mason M. Einbund, William H. Schulz ArcGIS Pro 3.0.36056 No formal attribute accuracy tests were conducted Independent Peer Review - data was checked for accuracy, duplication, and omission. Data set is considered complete for the information presented, as described in the abstract. Users are advised to read the rest of the metadata record carefully for additional details. Generally considered to be accurate. Used multiple geographic materials to confirm location No formal positional accuracy tests were conducted. Quantum Spatial 2017 remote-sensing image USA Quantum Spatial https://s3.amazonaws.com/fema-cap-imagery/Others/Maria https://storms.ngs.noaa.gov/storms/maria/index.html#18/18.28042/-66.66279 Digital and/or Hardcopy 2017 publication date FEMA This imagery was used to map landslides during Hurricane Maria in Puerto Rico. U.S. Geological Survey 2017 raster digital data USA U.S. Geological Survey ftp://rockyftp.cr.usgs.gov/vdelivery/Datasets/Staged/Elevation/OPR/PR_PuertoRico_2015/ Digital and/or Hardcopy 2015 2016 publication date LiDAR This raster was used to see the ground without vegetation interference. Gould, W.A., Alarcón, C., Fevold, B., Jiménez, M.E., Martinuzzi, S., Potts, G., Quiñones, M., Solórzano, M., and Ventosa, E. 2008 publication Río Piedras, PR U.S. Forest Service https://www.sciencebase.gov/catalog/item/560c3b2de4b058f706e5411e Digital and/or Hardcopy 2000 publication date Landcover This data was used to determine landcover/ecosystem types across the island. U.S. Department of Agriculture [USDA 2018 application/service USA : U.S. Department of Agriculture Natural Resources Conservation Service web page https://websoilsurvey.sc.egov.usda.gov/App/WebSoilSurvey.aspx Digital and/or Hardcopy 2018 publication date MUNAME This data was used to determine what kind of soil the failure occurred in. U.S. Census Bureau 2015 digital data United States Census Bureau U.S. Census Bureau t http://www2.census.gov/geo/tiger/TIGER2015/ PRISECROADS/tl_2015_72_prisecroads.zip Digital and/or Hardcopy 2015 publication date Roads This data was used to determine if impermeable road surfaces or any of the land movement used to make them were near and might affect slope failures. National Aeronautics and Space Administration [NASA 2017 application/service USA NASA https://nsidc.org/data/SPL4SMAU/versions/4. Digital and/or Hardcopy 2017 publication date SMAP This data was used to determine soil moisture during Hurricane Maria. Ramos-Scharrón, C.E., and Arima, E. 2019 publication USA Scientific Reports, v. 9, no. 1, article no. 15612 https://doi.org/10.1038/ s41598-019-52198-2 Digital and/or Hardcopy 2017 publication date Precipitation This data was used to determine the quantity of rainfall during Hurricane Maria. Bawiec, W.J. 1998 publication USA U.S. Geological Survey Open-File Report 98–038, p. 59–71 https://pubs.usgs.gov/of/1998/of98-038/ Digital and/or Hardcopy 1998 publication date Geology This data was used to determine the bedrock geology which the slope failures took place in. The lines were mapped using satellite imagery and LiDAR, and were drawn in relation to headscarp location and runout termination. FEMA LiDAR 2020 Attributing for lines included: 1. Whether the slide terminated at drainage, which was determined using FEMA imagery, LiDAR and the roads TIGER shapefile. 2. Length of line which was calculated using ArcMap tools 3. Fall height of the slide which was calculated using LiDAR 4. Height to Length ratio, which was calculated using LiDAR 5. Distance to road which was calculated using the road TIGER shapefile 6. Size of contributing watershed area which was calculated using LiDAR 2022 Vector G-polygon 1 Universal Transverse Mercator 19 0.9996 -69.0 0.0 500000.0 0.0 coordinate pair 0.6096 0.6096 meters WGS_1984 WGS_84 6378137.0 298.257223563 LinesDR.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. term_drain Whether the slide could not be mapped in its entirety because of ambiguity at drainages or where human activities modified deposits. Producer Defined n Mapping was not terminated at a drainage or similar Producer defined y Mapping was terminated at a drainage or similar Producer defined Length_m The length of the slide from headscarp to deposit toe Producer Defined 4.31299 494.04421 meters H_m The fall height from the highest elevation at the headscarp to the deposit toe. Producer Defined 4 252 meters (m) HLratio The ratio between fall height and length Producer Defined 0.00625 23.7232 Road_D_m Distance between any point on the line and the nearest mapped road. Producer Defined 0.0 275.173 meters (m) Wtrshd_m2 The watershed contributing area upslope from the upper end of the line Producer Defined 1 7121 square meters (m2) ScienceBase U.S. Geological Survey - Science Base mailing and physical

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Denver CO 80225 United States 1-888-275-8747 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 on any other system or for general or scientific purposes, nor shall the act of distribution constitute any such warranty. Digital Data ArcMap 10.6 https://doi.org/10.5066/P9UFKZS8 None 20240228 GHSC Data Steward US Geological Survey, Geologic Hazards Science Center mailing and physical

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Golden CO 80401 USA 303-273-8500 ghsc_metadata@usgs.gov Content Standard for Digital Geospatial Metadata FGDC-STD-001-1998