Carl J. Legleiter Lee R. Harrison 20191025 Force gage, grain size, and particle mass measurements from two reaches of the lower Merced River are stored in a .csv ASCII text file with columns for site, grain size class, force at motion, and particle axis lengths and mass. Reston, VA U.S. Geological Survey https://doi.org/10.5066/P99CWIDL Force gage measurements were used to parameterize a force balance model for the initation of sediment motion and thus characterize bed mobility for two reaches of the lower Merced River in California's Central Valley. These data were acquired to support research intended to evaluate the extent to which large-scale restoration projects provided improved salmon spawning habitat. A related goal of this study was to improve our understanding of the geomorphic factors influencing spawning site selection by salmon. The force gage measurements were made at the Merced River Ranch and Robinson Reach field sites and involved using a spring-resisting force gage to push a given submerged particle in a bed-parallel orientation and recording the minimum force necessary to initiate sediment motion, following the methods of Johnston et al., [1998]. For each particle, we also recorded the grain size class (22, 32, 45, 64, 90 or 128 mm), the length of the a, b and c axes of the sediment grain, and the particle's weight. These values were used to parametrize the force balance model of Wiberg and Smith [1987]. Force gage measurements were used to parameterize a force balance model for the initation of sediment motion and thus characterize bed mobility for two reaches of the lower Merced River in California's Central Valley. These data were acquired to support research intended to evaluate the extent to which large-scale restoration projects provided improved salmon spawning habitat. A related goal of this study was to improve our understanding of the geomorphic factors influencing spawning site selection by salmon. 2016 ground condition Complete None planned -120.62164306185 -120.39093017124 37.542399579313 37.433431483512 USGS Thesaurus Force gage River Salmon Sediment grain size Spawning bed mobility particle motion sediment transport USGS Metadata Identifier USGS:5bdb34dfe4b0b3fc5cee1008 Geographic Names Information System (GNIS) Merced River California none none Carl J Legleiter U.S. Geological Survey Geomorphology and Sediment Transport Laboratory mailing and physical

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Golden CO 80403 US 303-271-3651 cjl@usgs.gov This study was completed in collaboration with the National Oceanographic and Atmospheric Administration (NOAA) Southwest Fisheries Science Center. 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 The force gage measurements were made at the Merced River Ranch and Robinson Reach field sites and involved using a spring-resisting force gage to push a given submerged particle in a bed-parallel orientation and recording the minimum force necessary to initiate sediment motion, following the methods of Johnston et al., [1998]. For each particle, we also recorded the grain size class (22, 32, 45, 64, 90 or 128 mm), the length of the a, b and c axes of the sediment grain, and the particle's weight. These values were used to parametrize the force balance model of Wiberg and Smith [1987]. References: Johnston, C. E., E. D. Andrews, and J. Pitlick (1998), In situ determination of particle friction angles of fluvial gravels, Water Resour. Res., 34(8), 2017–2030, doi: 10.1029/98WR00312. Wiberg, P. L., and J. D. Smith (1987), Calculations of the critical shear stress for motion of uniform and heterogeneous sediments, Water Resour. Res., 23(8), 1471–1480, doi: 10.1029/WR023i008p01471. 2016 Carl J Legleiter USGS Geomorphology and Sediment Transport Laboratory Research Hydrologist mailing and physical

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Golden CO 80403 US 303-271-3651 cjl@usgs.gov Merced River, California Point Merced_forceGage Text file with measurements of grain size, mass, and force required for motion in eight columns: Site, D_m, Ax_m^2, V_m^3, z_m, phi_degrees, FL/FD_ratio, and f^2(z/z0) Producer defined Site Code for the field site on the Merced River from which the bulk sample was collected: MRR for Merced River Ranch or RR for Robinson Reach Producer defined MRR Merced River Ranch Producer-defined RR Robinson Reach Producer-defined D_m Grain diameter in meters for use in the Wiberg and Smith model. Producer defined 0.02 0.2 m Ax_m^2 Cross-sectional area of the grain perpendicular to the flow in square meters Producer defined 0.0003 0.03 square meters V_m^3 Grain volume in units of cubic meters Producer-defined NaN denotes missing data 0.00001 0.003 cubic meters z_m Grain height above the bed in units of meters Producer defined 0.013 0.205 meters phi_degrees Friction angle in units of degrees Producer defined 3 87 degrees FL/FD_ratio Ratio of the lift force, FL, to the drag force, FD, unitless Producer defined 0.1 2.9 unitless f^2(z/z0) Squared function for logarithmic vertical velocity profile, averaged over the cross-sectional area of the grain, A_x, with height above the bed z and roughness length, z_0 = D_50/30; unitless Producer defined 10 100 unitless U.S. Geological Survey - ScienceBase mailing and physical

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Denver CO 80225 USA 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. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government. The data you have secured from the U.S. Geological Survey (USGS) database identified as "Force gage measurements to characterize bed mobility in two restored reaches of the lower Merced River, California" have not received USGS approval and as such are provisional and subject to revision. The data are released on the condition that neither the USGS nor the U.S. Government shall be held liable for any damages resulting from its authorized or unauthorized use. Although these data have been processed successfully on a computer system at 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. The USGS or the U.S. Government shall not be held liable for improper or incorrect use of the data described and/or contained herein. The data are provided as a *.csv comma-separated text file that can be opened with a text editor such as Notepad, a spreadsheet program such as Excel, or a numerical computing software package such as MATLAB. 20200827 Carl J Legleiter U.S. Geological Survey Geomorphology and Sediment Transport Laboratory Research Hydrologist mailing and physical

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Golden CO 80403 US 303-271-3651 cjl@usgs.gov Content Standard for Digital Geospatial Metadata FGDC-STD-001-1998