Journal of Geophysical Research - Earth Surface
Supporting Information for
Particle friction angles in steep mountain channels
Jeff P. Prancevic and Michael P. Lamb
California Institute of Technology, Division of Geological and Planetary Sciences, 1200 E. California Blvd., MC 170-25,
Pasadena, CA, 91125
Contents of this file
N/A
Additional Supporting Information (Files uploaded separately)
Captions for Datasets S1 to S2
Introduction
This data set contains all of the field data used in this article. “Force Data_Supp.txt” contains all
of the site data and information for the individual measured grains. Individual txt files contain
all of the collected grain size data for each site.
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Data Set S1. “Force Data_Supp.txt”, all of the site data and data related to each force
measurement.
1.01 Column “Date”, date of measurement
1.02 Column “Reach Slope (%), percent slope of the reach calculated from a longitudinal profile
survey
1.03 Column “Bed Angle (º)”, the inverse tangent of the reach slope, in degrees
1.04 Column “Location ID”, reach name used in the article
1.05 Column “Lat (º)”, approximate latitude of the study reach
1.06 Column “Long (º)”, approximate longitude of the study reach
1.07 Column “Station (m)”, distance downstream from the start of the survey, in meters
1.08 Column “Width”, average width of the active channel along the study reach, in meters
1.09 Column “Exposure (downstream)(cm)”, average exposed length of the grain measured in
flow-parallel direction, in centimeters
1.10 Column “Exposure (cross-stream)(cm)”, average exposed length of the grain in the flowperpendicular, bed-parallel direction, in centimeters
1.11 Column “Exposure (depth)(cm)”, exposed length of the grain extending in the bed-normal
direction, measured relative to the bed topography half of the grain diameter upstream of the
grain, negative values reported as zero, in centimeters
1.12 Column “Size (downstream)(cm)”, length of the principal axis most-closely oriented in the
downstream direction, in centimeters
1.13 Column “Size (cross-stream)(cm)”, length of the principal axis most-closely oriented in the
cross-stream direction, in centimeters
1.14 Column “Size (depth)(cm)”, length of the principal axis most-closely oriented in the bednormal direction, in centimeters
1.15 Column “Est. Ellipse Weight (N)”, weight of the test grain as estimated from the principal
axes, assuming perfectly ellipsoidal shape and a material density of 2.65 g/cc, in newtons
1.16 Column “Weight (N)”, weight of the test grains used in calculations, most are measured
directly using the force gauge, but some weights are estimated from column 1.15 because the
weight was irresolvable with the force gauge or too difficult to measure with the force gauge, in
newtons
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1.17 Column “Force (N)”, the peak force required to remove the grain from its pocket, in
newtons
1.18 Column “Force/Weight”, Removal force divided by grain weight
1.19 Column “Step(1=y)”, indicates if the particle was in a step (1) or not (0)
1.20 Column “Friction angle (º)”, the particle friction angle for the grain, calculated using
equation (6) in the paper, in degrees
Data Set S2. Grain size data for each site in separate files.
2a. “ds01.txt”, Median grain diameter measurements at the Sespe Creek Bar reach, in cm
2b. “ds02.txt”, Median grain diameter measurements at the Rose Valley Tributary reach, in cm
2c. “ds03.txt”, Median grain diameter measurements at the Rattlesnake Creek reach, in cm
2d. “ds04.txt”, Median grain diameter measurements at the Tumble Creek reach, in cm
2e. “ds05.txt”, Median grain diameter measurements at the Arroyo Seco reach, in cm
2f. “ds06.txt”, Median grain diameter measurements at the Sespe Creek Thalweg reach, in cm
2g. “ds07.txt”, Median grain diameter measurements at the San Oline Creek reach, in cm
2h. “ds08.txt”, Median grain diameter measurements at the Block Creek reach, in cm
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