Jonathan Casey Root 20231025 vector digital data https://doi.org/10.5066/P9DGG75W This section of the data release includes the spatial metadata geospatial polygon feature dataset (.shp file) that contains spatial footprints for each input source dataset used to develop the topobathymetric dataset of Great Salt Lake. The attributes for each footprint polygon describe the characteristics of each input dataset used to generate the topobathymetric dataset. The primary purpose of this dataset is to provide an updated topobathymetric representation of Great Salt Lake for use in geographic information systems. Area and volume calculations were done in support of additional studies that model salt load in Great Salt Lake. 2002 20161130 ground condition Complete None planned Great Salt Lake -113.0700 -111.9200 41.7000 40.6600 ISO 19115 Topic Category elevation geoscientificInformation inlandWaters society USGS Thesaurus topography digital elevation models bathymetry geospatial analysis None topobathymetric digital elevation model TBDEM DEM elevation USGS U.S. Geological Survey 3D Elevation Program 3DEP topobathymetry Light Detection and Ranging lidar Utah Water Science Center Acoustic Sonar Inland Bathymetry Reservoir Storage Capacity Flood Inundation Modeling saline lakes USGS Metadata Identifier USGS:6467b3e3d34ec11ae4a8ae87 Geographic Names Information System (GNIS) Great Salt Lake Utah Salt Lake City Great Salt Lake Desert Wasatch Range Bear River Jordan River Utah Lake Gilbert Bay Fremont Island Antelope Island Promontory Point Farmington Bay Carrington Bay Bear River Bay Box Elder County Salt Lake County Tooele County Davis County Weber County 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. Jonathan Casey Root U.S. Geological Survey, ROCKY MOUNTAIN REGION Hydrologist mailing address

2329 West Orton Circle

West Valley City UT 84119 US 801-908-5000 jroot@usgs.gov Utah Geological Survey; Utah Division of Forestry, Fire and State Lands; Utah Geospatial Resource Center No formal attribute accuracy tests were conducted. No formal logical accuracy tests were conducted. Dataset 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. No formal positional accuracy tests were conducted. No formal positional accuracy tests were conducted. Robert L. Baskin 2005 publication Reston, VA U.S. Geological Survey Unpublished source vector data (R.L. Baskin, personal communication, 2022) https://pubs.er.usgs.gov/publication/ofr20051327 Digital and/or Hardcopy 2002 2004 publication date Baskin, 2005 Source data for interpolated bathymetry of south arm in Great Salt Lake Robert L. Baskin 2006 publication Reston, VA U.S. Geological Survey Unpublished source vector data (R.L. Baskin, personal communication, 2022) https://pubs.er.usgs.gov/publication/ofr20061359 Digital and/or Hardcopy 2006 publication date Baskin, 2006 Source data for interpolated bathymetry of north arm in Great Salt Lake Utah Geospatial Resource Center 2016 raster digital data https://gis.utah.gov/data/elevation-and-terrain/2016-lidar-gsl/ Digital and/or Hardcopy 20160903 20161130 publication date 2016 Great Salt Lake and Utah Lake LiDAR Elevation Data Topographic lidar data within and surrounding Great Salt Lake DEVELOP DIGITAL ELEVATION MODEL OF BATHYMETRY FROM CONTOUR DATA: Bathymetry of the south arm of Great Salt Lake was surveyed between 2002–2004 using a single-beam, high-definition fathometer and real-time differential global positioning system (Baskin 2005, Baskin 2006). Bathymetric data in the south arm were acquired for elevations below 4,193 ft above the National Geodetic Vertical Datum of 1929 (NGVD 29). The bathymetry of the north arm was surveyed in 2006 and includes bathymetric data below 4,194 ft above NGVD 29. Baskin (2005, 2006) incorporated 1:24,000 U.S. Geological Survey digital line graph data above those elevations in the original published maps; those data are removed in this dataset. Bathymetric contour vector data were interpolated into a digital elevation model raster of the bathymetry in Great Salt Lake using the Topo to Raster tool in ArcGIS Pro (v. 2.9.5). The source contour interval was 0.5 feet (0.152 m); the raster was interpolated to a cell size of 0.5 meters in agreement with the 2016 QL1 lidar dataset. The following inputs were used in Topo to Raster: INPUT FEATURE DATA contours (feature class - polyline), streams (feature class - polyline), lakes (feature class - polygon); OUTPUT CELL SIZE 0.5; MARGIN IN CELLS 5; DRAINAGE ENFORCEMENT “Do not enforce”; PRIMARY TYPE OF INPUT DATA “Contour”; MAXIMUM NUMBER OF ITERATIONS 30; ROUGHNESS PENALTY “N/A”; PROFILE CURVATURE ROUGHNESS PENALTY “N/A”; DISCRETISATION ERROR FACTOR 0.25; VERTICAL STANDARD ERROR 0; TOLERANCE 1 0.5; TOLERANCE 2 100. Minimum and maximum elevations reflect the range from the original datasets. Minor warping may be found along the causeway where the contours converge. Elevations were converted to meters above the North American Vertical Datum of 1988. 20220901 Jonathan Casey Root U.S. Geological Survey, ROCKY MOUNTAIN REGION Hydrologist mailing address

2329 West Orton Circle

West Valley City UT 84119 US 801-908-5000 jroot@usgs.gov MOSAIC INTERPOLATED BATHYMETRY WITH LIDAR DATA: Lidar elevation data were acquired between September 3–November 30, 2016, by the Utah Geospatial Resource Center, Utah Geological Survey, and Utah Division of Forestry, Fire and State Lands. The dataset includes complete coverage of Great Salt Lake with 1-meter QL2 data with select regions with 0.5-meter QL1 data. Accuracy in both datasets have a ≤10.0-cm vertical root-mean-square error. The water surface, which is represented by a hydro-flattened elevation values in the north and south arm was clipped from the datasets to be replaced with the interpolated bathymetry; these values were 1,277.650024 and 1,278.660034 m above the North American Vertical Datum of 88 in the published lidar datasets for the north and south arms, respectively. The lidar and bathymetry were combined using the Mosaic to New Raster tool in ArcGIS Pro (v. 2.9.5) to generate the seamless topobathymetric surface from 1,271.04–2,028.39 m above the North American Vertical Datum of 1988. Where the datasets overlap, the 0.5-meter interpolated bathymetry was given the highest priority, followed by the 0.5-meter and then 1.0-meter topographic lidar which was resampled to 0.5 meters and converted from meters to feet above the North American Vertical Datum of 88. The unit conversion was done prior to calculating volume and area in concordance with USGS lake level gages at Saltair (USGS station ID 10010000) and Saline (USGS station ID 10010100) and to produce elevation-area-volume tables at even 0.01-foot intervals. 20230901 Jonathan Casey Root U.S. Geological Survey, ROCKY MOUNTAIN REGION Hydrologist mailing address

2329 West Orton Circle

West Valley City UT 84119 US 801-908-5000 jroot@usgs.gov CALCULATE ELEVATION-VOLUME-AREA RELATIONSHIPS: The volume and area of Great Salt Lake were calculated with the Storage Capacity tool, part of the Spatial Analyst Supplemental Toolbox in ArcGIS Pro (v. 2.9.5). The tool calculates the volume and area at desired increments of elevation for the input raster. The topobathymetric dataset was resampled from a cell size of 0.5 meters to 5 meters prior to calculating volume and area due to processing limitations. It was then divided into smaller geographic regions, converted from meters to feet above the North American Vertical Datum of 88, and processed for volume and area at elevation increments of 0.01 feet between 4,170.00–4,215.00 ft above the North American Vertical Datum of 1988. Assessment for volume and area change due to cell-size resampling was checked at lower, middle, and upper elevations of the 0.5-meter topobathymetric dataset; volume and area values at all elevations and both raster resolutions were within ±0.003% difference. 20230301 Jonathan Casey Root U.S. Geological Survey, ROCKY MOUNTAIN REGION Hydrologist mailing address

2329 West Orton Circle

West Valley City UT 84119 US 801-908-5000 jroot@usgs.gov Raster Pixel 202228 248919 Universal Transverse Mercator 12 0.9996 -111.0 0.0 500000.0 0.0 row and column 0.5 0.5 meters North American Datum of 1983 (NAD 83) Geodetic Reference System 1980 6378137.000000 298.257222 North American Vertical Datum of 1988 0.000001 meters Attribute values Great Salt Lake TBDEM Spatial Metadata Shapefile containing spatial metadata information detailing source datasets used to create the Great Salt Lake TBDEM. Producer Defined FID Internal feature number. ESRI Sequential unique whole numbers that are automatically generated. Shape Feature geometry. ESRI Shape type. Name Shorthand dataset name Producer Defined bathy_south 2016 bathymetry for south arm of Great Salt Lake Producer defined bathy_north 2016 bathymetry for north arm of Great Salt Lake Producer defined lidar_QL1 2016 QL1 lidar of and around Great Salt Lake Producer defined lidar_QL2 2016 QL2 lidar of and around Great Salt Lake Producer defined Title Source dataset name Producer Defined 2002-2004 0.5-meter interpolated bathymetry Interpolated bathymetry of south arm of Great Salt Lake Producer defined 2006 0.5-meter interpolated bathymetry Interpolated bathymetry of north arm of Great Salt Lake Producer defined 2016 0.5-meter QL1 lidar 2016 QL1 lidar of and around Great Salt Lake Producer defined 2016 1-meter QL2 lidar 2016 QL2 lidar of and around Great Salt Lake Producer defined Source Publication source for data Producer Defined Calculation of area and volume for the south part of Great Salt Lake, Utah Calculation of area and volume for the south part of Great Salt Lake, Utah Producer defined Calculation of area and volume for the north part of Great Salt Lake, Utah Calculation of area and volume for the north part of Great Salt Lake, Utah Producer defined 2016 Great Salt Lake and Utah Lake LiDAR Elevation Data 2016 Great Salt Lake and Utah Lake LiDAR Elevation Data Producer defined Source_Org Organization responsible for collection of data Producer Defined USGS USGS Producer defined Utah Geospatial Resource Center Utah Geospatial Resource Center Producer defined Date_Acq Date data were acquired Producer Defined 2002-2004 Survey year range Producer defined 2005 Survey year Producer defined 2016 Survey year Producer defined Date_Pub Year of publication Producer Defined 2005 Publication year Producer defined 2006 Publication year Producer defined 2017 Publication year Producer defined Data_Type Input elevation type Producer Defined Interpolated bathymetry from contour bathymetry Interpolated bathymetry from contour bathymetry Producer defined Topographic lidar Topographic lidar Producer defined Source_VD Input source vertical datum Producer Defined NGVD29 National Geodetic Vertical Datum of 1929 Producer defined NAVD88 North American Vertical Datum of 1988 Producer defined Source_Res Input source horizontal resolution Producer Defined 1-ft contour intervals; 0.5-m interpolated raster Source and interpolated resolution Producer defined 0.5 m Source resolution Producer defined Source_HD Input source horizontal datum Producer Defined NAD83; UTM 12N The North American Datum of 1983 (NAD 83); Universal Transverse Mercator, Zone 12 North Producer defined NAD83(2011) / UTM zone 12N The North American Datum of 1983 (NAD 83) with 2011 adjustments; Universal Transverse Mercator, Zone 12 North Producer defined Source_Unt Units of source data Producer Defined feet U.S. customary units Producer defined meters International System of Units Producer defined Source_Geo Input source geoid Producer Defined GEOID12B Used to convert the ellipsoidal height obtained by the Global Navigation Satellite System (to the orthometric height of a specific vertical datum. The Geoid 12B model transforms between NAD 83 (2011/PA11/MA11) and the respective vertical datums. Producer defined Source_Web Web link to input source dataset Producer Defined https://doi.org/10.3133/ofr20051327 Digital object identifier URL for Calculation of area and volume for the south part of Great Salt Lake, Utah Producer defined https://doi.org/10.3133/ofr20061359 Digital object identifier URL for Calculation of area and volume for the north part of Great Salt Lake, Utah Producer defined https://gis.utah.gov/data/elevation-and-terrain/2016-lidar-gsl/ URL for 2016 Great Salt Lake and Utah Lake LiDAR Elevation Data Producer defined Area_acres Area of spatial polygon feature in acres Producer Defined 254432.0 489945.0 acres This collection of high-resolution topobathymetric digital elevation data is available in a user-friendly Georeferenced Tagged Image File Format (GeoTIFF) at ScienceBase online at https://doi.org/10.5066/P9DGG75W. The elevation model has floating point numeric values. Spatial metadata includes a geospatial polygon feature dataset (.shp file) that contains spatial footprints for each input source dataset. The attributes for each footprint polygon describe the characteristics of each input dataset used to generate the topobathymetric dataset. This data release includes comma delimited (CSV) files for: (1) calculated tables of elevation-area-volume relationships for Great Salt Lake, in total, at 0.01-ft intervals; (2) calculated tables of elevation-area-volume relationships for the north arm of Great Salt Lake at 0.01-ft intervals; (3) calculated tables of elevation-area-volume relationships for the south arm of Great Salt Lake at 0.01-ft intervals; (4) calculated tables of elevation-area-volume relationships for Bear River Bay of Great Salt Lake at 0.01-ft intervals; and (5) calculated tables of elevation-area-volume relationships for Farmington Bay of Great Salt Lake at 0.01-ft intervals. Root, J.C., 2023, Half-meter topobathymetric elevation model and elevation-area-volume tables for Great Salt Lake, Utah, 2002-2016: U.S. Geological Survey data release, https://doi.org/10.5066/P9DGG75W U.S. Geological Survey GS ScienceBase mailing address

Denver Federal Center, Building 810, Mail Stop 302

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 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/P9DGG75W None 20231025 Jonathan Casey Root U.S. Geological Survey, ROCKY MOUNTAIN REGION Hydrologist mailing address

2329 West Orton Circle

West Valley City UT 84119 US 801-908-5000 jroot@usgs.gov FGDC Biological Data Profile of the Content Standard for Digital Geospatial Metadata FGDC-STD-001.1-1999