On extracting sediment transport information from measurements of luminescence in river sediment Harrison J. Gray1,2*, Gregory E. Tucker2, Shannon A. Mahan1, Chris McGuire3, Edward J. Rhodes3,4 1 Cooperative Institute for Research in Environmental Sciences (CIRES) and Department of Geological Sciences, University of Colorado – Boulder, CO 2 U.S. Geological Survey Luminescence Geochronology Laboratory, Denver Federal Center, Denver, CO 3 Department of Earth, Planetary, and Space Sciences, University of California Los Angeles, Los Angeles, CA 4Department of Geography, University of Sheffield, Sheffield, S10 2TN, United Kingdom *corresponding author:
[email protected] KEY POINTS We develop a model coupling sediment transport of fine sand and luminescence, in order to explain the patterns of luminescence observed in river sediment The model successfully reproduces the patterns of luminescence measurements in river systems Best-fit values from the model produce sediment transport information for fine sand within orders of magnitude from other river systems ABSTRACT Accurately quantifying sediment transport rates in rivers remains an important goal for geomorphologists, hydraulic engineers, and environmental scientists. However, current techniques for measuring transport rates are laborious, and formulae to predict transport are notoriously inaccurate. Here, we attempt to estimate sediment transport rates using luminescence, a property of common sedimentary minerals that is used by the geoscience community for geochronology. This method is advantageous because of the ease of measurement on ubiquitous quartz and feldspar sand. We develop a model based on conservation of energy and sediment mass to explain the patterns of luminescence in river channel sediment from a first- principles perspective. We show that the model can accurately reproduce the luminescence observed in previously published field measurements from two rivers with very different sediment transport styles.