Paul E Grams Laura V Alvarez Matt Kaplinski Scott A Wright 20210723 comma-separated values (csv) Flagstaff, AZ U.S. Geological Survey https://doi.org/10.5066/P9O00Z44 Laura V. Alvarez Paul E. Grams 20211006 publication Journal of Geophysical Research: Earth Surface vol. 126, issue 10 n/a American Geophysical Union (AGU) https://doi.org/10.1029/2021JF006149 These topographic/bathymetric digital elevation models (DEMs) were collected and compiled to characterize erosion and deposition in the Colorado River and in an adjacent zone of laterally recirculating flow (eddy) during both average flow conditions and during a controlled flood that occurred in March 2008. The objectives of the study were to measure changes sandbar morphology that occurred during changes in discharge associated with the controlled flood. These data were collected between February 6 and March 31, 2008 in a 1-mile study reach on the Colorado River within Grand Canyon National Park beginning 44.5 miles downstream from Lees Ferry, Arizona. These data were collected by the USGS Grand Canyon Monitoring and Research Center with cooperators from Northern Arizona University and funding provided by the Glen Canyon Dam Adaptive Management Program. All bathymetric data were collected with a multibeam sonar system (Reson Seabat 8124 sonar with TSS MAHRSS reference system for heave, pitch, roll, and heading). Topographic data were collected by conventional total station. These data can be used to study changes in channel morphology associated with changes in streamflow conditions. The purpose of these data is to better understand the relation between discharge, streamflow velocity, and sediment transport for use in predictive models of sediment transport and deposition and erosion. These data were created to test predictions of sediment erosion and deposition for the March 2008 controlled flood released from Glen Canyon Dam. It was also anticipated that these data would be used to build and calibrate future models for streamflow and sediment transport. These data can be used to characterize channel topography and bathymetry for the indicated dates and times and can be considered to accurately represent the channel at the 1-m resolution that is provided. The high-density multibeam sonar measurements of bathymetry provide a good estimate of the average elevation of each 1-m grid. However, because of this averaging, these data do not provide a detailed characterization of surface roughness for scales smaller than 1 meter. Because much of the study reach is mobile sand, the channel morphology is subject to change with changes in streamflow and sediment supply. These data therefore cannot be assumed to be accurate for any times other than the times of data collection. Data users should read the entire metadata record and acquire any manuscript identified as ‘Larger Work Citation' to have a complete understanding of how these data were created and used. The data are specific to the uses identified in the metadata record and any other use of these data would be inappropriate. See 'Distribution liability' statements for more information. 20080206 20080331 ground condition Complete None planned -114.02379 -111.476798 36.965854 35.740126 USGS Thesaurus bathymetry bathymetry measurement controlled flooding digital elevation models field experiments freshwater ecosystems hydrology multibeam sonar sediment transport sedimentation stream discharge streamflow topography ISO 19115 Topic Categories inlandWaters USGS Metadata Identifier USGS:60f9e4c1d34e3ccd82fee7f6 None channel morphology eddies erosion deposition Glen Canyon Dam Adaptive Management Program high-flow experiment lateral flow separation zones predictive models recirculating flow Reson Seabat 8124 sonar with TSS MAHRSS reference system sandbars sandbar morphology sediment erosion sediment depostion streamflow velocity profile measurements stream channel streamflow condtions streamflow models streamflow velocity topographic data total station USGS Grand Canyon Monitoring and Research Center Geographic Names Information System (GNIS) Arizona Colorado River Eminence Break Glen Canyon Dam Grand Canyon National Park Lees Ferry Marble Canyon None Eminence Break field site river mile 44.5 river mile 45 Willie Taylor field site none none Paul E Grams U.S. Geological Survey Research Hydrologist mailing and physical

Mail Stop 9395, 2255 North Gemini Drive

Flagstaff AZ 86001 US 928-556-7385 pgrams@usgs.gov This research was funded by the U.S. Bureau of Reclamation through the Glen Canyon Dam Adaptive Management Program. No formal attribute accuracy tests were conducted No formal logical accuracy tests were conducted 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. No formal positional accuracy tests were conducted No formal positional accuracy tests were conducted Development of the DEM_RM44_20080206_1200.csv to DEM_RM44_20080331_1600.csv data tables (15 files): Bathymetry was surveyed with a multibeam sonar system (Reson Seabat 8124 sonar with TSS MAHRSS reference system for heave, pitch, roll, and heading) deployed from a motorized inflatable raft. Boat position and elevation were tracked using a robotic total station. Areas above water and shallow areas near the shoreline were surveyed with conventional total station techniques. The multibeam and conventional surveys were combined and converted to 1 m grids to create a single digital elevation model. The conventional survey point density was about 0.5 to 1 points per square meter and the multibeam density varied from 10 to 1000 points per square meter depending on boat speed and sweep overlap. DEMs created from different surveys were compared over stable surfaces, such as gravel bars and bedrock. These differences ranged from 8 to 10 cm at 95% RMS. 2008 Development of the DEM_RM45_2008027_1100.csv to DEM_RM45_20080331_1200.csv data tables (13 files): Bathymetry was surveyed with a multibeam sonar system (Reson Seabat 8124 sonar with TSS MAHRSS reference system for heave, pitch, roll, and heading) deployed from a motorized inflatable raft. Boat position and elevation were tracked using a robotic total station. Areas above water and shallow areas near the shoreline were surveyed with conventional total station techniques. The multibeam and conventional surveys were combined and converted to 1 m grids to create a single digital elevation model. The conventional survey point density was about 0.5 to 1 points per square meter and the multibeam density varied from 10 to 1000 points per square meter depending on boat speed and sweep overlap. DEMs created from different surveys were compared over stable surfaces, such as gravel bars and bedrock. These differences ranged from 8 to 10 cm at 95% RMS. 2008 Data Quality Assessment and Quality Control (QAQC): The topographic and bathymetric data contained in this data release underwent multiple levels of quality control between data collection and the final gridded DEMs. In the field, survey instruments were set on stable reference points and oriented by backsight to secondary stable reference points. Position accuracy was verified by repetition measurements to the backsight on every survey. If horizontal error exceeded 2.0 cm or vertical error exceeded 2.0cm, the source of the error was identified and corrected, and the repetition measurements were repeated until errors were within those tolerances. Survey data were collected on electronic data loggers, eliminating most errors associated with data entry. Errors associated with incorrect labeling of points or incorrect survey rod height were identified in the officed and corrected. These errors were identified by generating a preliminary Triangle Irregular Network (TIN) topographic surface model and visually inspecting the TIN model for spikes or inconsistencies. A new TIN was created following these edits and used to generate the gridded text files. For the bathymetric data, system alignment was obtained by performing patch tests in the field, which yielded corrections for heading (yaw), roll, pitch, and timing (latency). The patch test corrections were applied to all sounding. The raw data was inspected in the office and edited to remove bad soundings (i.e. outliers). Final quality control on the surface models and gridded text files was completed in 2011. 2001 Finalize Data File for Dissemination: Data sent to the Southwest Biological Science Center Data Steward for dissemination and preservation per USGS Data Management Policies SM 502.6, SM 502.7, SM 502.8 and SM 502.9 (1 October 2016). 2021 DEM_RM44_20080206_1200.csv to DEM_RM44_20080331_1600.csv (15 files) These data represent the results from surveys of river bathymetry for the RM44 (Eminence Break) site collected before, during, and after the March 2008 high-flow experiment from Glen Canyon Dam on the Colorado River. Surveys were typically performed twice per day at each site, yielding 15 surveys of RM44 and 12 surveys of RM45. The filenames are in the format: DEM_SITE_YYYYMMDD_HHMM. Producer defined column 1 Easting: eastward-measured distance (or the x-coordinate) in meters. The horizontal positions are NAD83, Arizona State Plane Central Zone. Elevations are ellipsoid heights referenced to the Geodetic Reference System 1980 (GRS 80) ellipse defined by the North American Datum of 1983 (NAD83). Producer defined 219018.06 219478.44 meters column 2 Northing: northward-measured distance (or the y-coordinate) in meters. The horizontal positions are NAD83, Arizona State Plane Central Zone. Elevations are ellipsoid heights referenced to the Geodetic Reference System 1980 (GRS 80) ellipse defined by the North American Datum of 1983 (NAD83). Producer defined 597154.261 597577.064 meters column 3 Elevation Producer defined 821.898 844.879 meters DEM_RM45_2008027_1100.csv to DEM_RM45_20080331_1200.csv (13 files) These data represent the results from surveys of river bathymetry for the RM45 (Willie Taylor) site collected before, during, and after the March 2008 high-flow experiment from Glen Canyon Dam on the Colorado River. Surveys were typically performed twice per day at each site, yielding 15 surveys of RM44 and 12 surveys of RM45. The filenames are in the format: DEM_SITE_YYYYMMDD_HHMM. Producer defined column 1 Easting: eastward-measured distance (or the x-coordinate) in meters. The horizontal positions are NAD83, Arizona State Plane Central Zone. Elevations are ellipsoid heights referenced to the Geodetic Reference System 1980 (GRS 80) ellipse defined by the North American Datum of 1983 (NAD83). Producer defined 218532.55 218917.554 meters column 2 Northing: northward-measured distance (or the y-coordinate) in meters. The horizontal positions are NAD83, Arizona State Plane Central Zone. Elevations are ellipsoid heights referenced to the Geodetic Reference System 1980 (GRS 80) ellipse defined by the North American Datum of 1983 (NAD83). Producer defined 597082.09 597252.632 meters column 3 Elevation Producer defined 820.037 846.989 meters U.S. Geological Survey - ScienceBase U.S. Geological Survey mailing and physical

Denver Federal Center, Building 810, Mail Stop 302

Denver CO 80225 United States 1-888-275-8747 sciencebase@usgs.gov The author(s) of these data request that data users contact them regarding intended use and to assist with understanding limitations and interpretation. 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. The data in this zip file contains data in comma-separated values (csv) file format. The user must have software capable of uncompressing the zip file and software capable of reading machine-readable tabular data. 20210723 Paul E Grams U.S. Geological Survey Research Hydrologist mailing and physical

Mail Stop 9395, 2255 North Gemini Drive

Flagstaff AZ 86001 US 928-556-7385 pgrams@usgs.gov Content Standard for Digital Geospatial Metadata FGDC-STD-001-1998