Supporting code and datasets for "Tracking the trajectory of alluvial channel adjustment reveals along-river shifts in sediment mobility "

This document described the data and codes supporting the manuscript "Tracking the trajectory of alluvial channel adjustment reveals along-river shifts in sediment mobility" - Masteller et al., in review. This repository code was written to complete analysis outlined in Masteller et al. (in review). It has been modified from its original form to improve readability and ease of implementation for general users. You may need to modify the code for your specific applications. You are responsible for inspecting the code and making adjustments as necessary. /SummaryData/1. Reach_Summary_Final.csv - Reach-scale summaries for the South Fork Eel study sites including reach coordinates and morphology measures. 2. NREE_data_compilation.csv - Compiled data from Phillips et al., 2022. Used in Figure 2. /scripts/1. widthCalcfromBanklines.m - Processes paired left and right bankline CSV files to compute channel width along the South Fork Eel River, generate quality-control plots, and export width and bank-coordinate outputs as CSVs for downstream analyses. 2. DepthsFromWidths.m - Computes median and maximum channel depths and channel geometry metrics from QAQC’d balkline widths and cross-section elevation profiles, generates diagnostic plots, and exports per-site depth metrics to CSV. 3. reachSlopes.m - Derives channel slopes from a longitudinal profile, samples elevation and slope around grain-size survey locations, and exports per-site slope metrics and reach-scale summaries. /input/├── banklines/ - contains .CSV files of bankline positions for each study reach, two files per reach. File headers indicate ID_number of cross-section from original width extraction (see Kostynick et al., 2026), original bank positions (Easting, Northing), and refined positions (Easting2, Northing2) and bank elevations of refined positions (Elevation2)├── centerline/ - contains .CSV file of channel centerline derived from 10-m USGS 3DEP product using Topotoolbox. File headers indicate distance downstream (D), Easting and Northing, drainage area (A), and elevation (Z). ├──crossSections/ - Matlab structure arrays containing channel cross-sections extracted using methods described in Kostynick et al., 2026 using 1-m topobathymetric lidar data product from Dietrich, 2014. Data are split between Upper Eel and Lower Eel river. Cross-sections are contained within the structure array as width_extract.Zprof with corresponding distances in width_extract.dist or thalweg-centered distances as width_extract.dist_center└── DEM/ - contains USGS 3DEP 10-m DEM used to extract channel centerline, downloaded from OpenTopography /output/├── widths/ - contains .CSV files of bank-to-bank widths output from widthCalcfromBanklines.m. File headers indicate site identifier, the ID number of cross-section from original width extraction (see Kostynick et al., 2026), the coordinates and elevations of each bank, and the extracted bank-to-bank widths├── depths/ - contains .CSV files of depths output from DepthsFromWidths.m. File headers indicate the site identifier, the ID number of cross-section from original width extraction (see Kostynick et al., 2026), the elevation of each bank, the average and maximum bank elevations by cross-section, the average extracted depth, wetted perimeter, cross-sectional area, and hydraulic radius, and the maximum extracted depth, wetted perimeter, cross-sectional area, and hydraulic radius.├── slopes/ contains .CSV files of slopes output from reachSlopes.m. File headers indicate the site identifier, the distance downstream from the original centerline file, the elevation, and the local slope.└── plots/ landing output folder for QAQC plots generated from width, depth, and slope extraction scripts. Contains one set of sample plots. References: R. P. Kostynick, C. B. Phillips, C. C. Masteller, High-Resolution Channel Geometry Reveals Contrasting Styles of Gravel River Adjustment. Geophysical Research Letters (2026). https://doi.org/10.1029/2025GL118412. Kostynick, R. (2025). Supporting datasets and code for "High-Resolution Channel Geometry Reveals Contrasting Styles of Gravel River Adjustment" [Data set]. Zenodo. https://doi.org/10.5281/zenodo.17536841 Dietrich, W. E. (2014). Eel River Critical Zone Observatory July 2014 Lidar Survey [Data set]. Distributed by OpenTopography: National Center for Airborne Laser Mapping (NCALM). https://doi.org/10.5069/G9MP517V Phillips, C. B., Masteller, C. C., Slater, L. J., Dunne, K. B. J., Francalanci, S., Lanzoni, S., et al. (2022). Threshold constraints on the size, shape and stability of alluvial rivers. Nature Reviews Earth & Environment, 1–14. https://doi.org/10.1038/s43017-022-00282-z Schwanghart, W. (2022). Release TopoToolbox 2.4 [Computer software]. Github. wschwanghart/topotoolbox. Retrieved November 5, 2025, from https://github.com/wschwanghart/topotoolbox/releases/tag/2.4 Schwanghart, W., & Scherler, D. (2014). Short Communication: TopoToolbox 2 – MATLAB-based software for topographic analysis and modeling in Earth surface sciences. Earth Surface Dynamics, 2(1), 1-7-1–7. https://doi.org/10.5194/esurf-2-1-2014