DOI: 10.5281/zenodo.18344109
title: SWOT-River-Volume: Data products associated with computing river storage variability from SWOT observations

description: Corresponding peer-reviewed publication

This dataset corresponds to all input and output files that were used in the study reported in:



Cerbelaud, A.*, Wade, J.*, David, C.H., Durand, M., Frasson R.P.M., Pavelsky T., and Oubanas. Wide-Swath Altimetry Maps Bank Shapes and Storage Changes in Global Rivers. Nature. https://doi.org/10.1038/s41586-026-10218-y.


          * These authors contributed equally.

When making use of any of the files in this dataset, please cite both the aforementioned article and the dataset herein.

Summary

The SWOT-River-Volume data product transforms global observations of river water surface elevation and width provided by the Surface Water and Ocean Topography (SWOT) mission into estimates of active riverbed shapes (channel bathymetry between the lowest and highest observed water levels) and river water storage variability worldwide, along with its uncertainty. We provide the first observationally-derived global river water storage estimates from the first year of SWOT data (version C) along 126,674 reaches in the SWOT River Database (SWORD; Altenau et al., 2021). We also validate and compare SWOT's observations of global river variability to in situ GRDC gauge data and the current, publicly available, best estimates of river volume changes obtained through river routing simulations (MeanDRS, Collins et al., 2024). Finally, we provide a sensitivity analysis of SWOT’s input uncertainties to the resulting river volume changes, and an outlier analysis of the final derived database with regards to the underlying SWORD hydrological network.

SWOT-River-Volume aims to:

1.     Download and prepare SWOT width and height observations for volume estimation.

2.     Compute river volume variability with its uncertainty from SWOT observations using river hypsometry.

3.     Provide comparisons between SWOT-derived river volume estimates and (i) in situ GRDC gauge data, and (ii) MeanDRS volume simulations worldwide.

4.     Perform a sensitivity analysis of SWOT’s input uncertainties to the resulting river volume changes.

5.     Provide an outlier analysis of the final estimates with regards to the underlying SWORD hydrological network.

Software

The software that was used to produce files in this dataset are available in this repository (SWOT-river-volume-code.zip) and at https://github.com/jswade/SWOT-river-volume.

Primary Data Products

The following files represent the primary data products of the SWOT-river-volume dataset. In general, each file class is split over the 61 global Pfafstetter basins. The data products can be broken down into files corresponding to inputs used by automated scripts and outputs produced by those scripts.

The SWOT-river-volume input files available here correspond to global SWOT L2 HR River Single Pass version C observations downloaded through the NASA PODAAC Hydrocron service.



input.zip:






/SWOT/swot_pfaf_ii_2023-10-01_2024-09-30.csv: Files containing downloaded SWOT observations of width, height, and associated attributes for each region.



The output files correspond to primary outputs of our analysis, including reach-specific volume time series, hypsometric fit quality statistics, basin volume anomalies, and comparisons to MeanDRS volume simulations.



output_revision.zip:



/V_EIV/



swot_vol_pfaf_ii_2023-10-01_2024-09-30.csv: Files containing reach-specific volume time series produced through river hypsometry in each region.

swot_volunc_pfaf_ii_2023-10-01_2024-09-30.csv: Files containing reach-specific volume uncertainty time series produced through river hypsometry in each region.



/EIV_fits/swot_vol_fits_ii_2023-10-01_2024-09-30.csv: Files containing information regarding hypsometric fit parameters and fit quality statistics in each region.

/V_anom/



V_anom_pfaf_ii_2023-10-01_2024-09-30.csv: Files containing reach-specific monthly volume anomalies in each region.

VUnc_anom_pfaf_ii_2023-10-01_2024-09-30.csv: Files containing reach-specific monthly volume anomalies uncertainties in each region.



/MeanDRS_comp/



/SWOT/V_SWOT_comp_pfaf_ii_2023-10-01_2024-09-30.csv: Files containing SWOT volume anomalies prepared for comparison to MeanDRS in each region.

/SWOT/VUnc_SWOT_comp_pfaf_ii_2023-10-01_2024-09-30.csv: Files containing SWOT volume anomalies uncertainties prepared for comparison to MeanDRS in each region.

/MeanDRS/V_MeanDRS_comp_pfaf_ii_2023-10-01_2024-09-30.csv: Files containing aggregated MeanDRS volume anomalies at reaches corresponding to observed SWORD reaches in each region.



/MeanDRS_scale/V_SWOT_scale_pfaf_ii_2023-10-01_2024-09-30.csv: Files containing MeanDRS volume anomalies over the 30-year record at reaches corresponding to observed SWORD reaches using for SWOT volume scaling in each region.

/MeanDRS_slice/V_SWOT_slice_pfaf_ii_2023-10-01_2024-09-30.csv: Files containing SWOT volume anomalies (main, low and high) and annual slices of MeanDRS volume anomalies at reaches corresponding to observed SWORD reaches in each region.

/n_obs/swot_n_obs.csv: File containing the proportion of reaches with valid SWOT volume computations.

/SWORD_reach_anom/SWORD_obs_anom_pfaf_ii.shp: Shapefiles containing observed SWOT volume anomalies joined to SWORD shapefiles for visualization in each region.

/SWORD_reach_anom_outliers/SWORD_obs_anom_pfaf_ii_outliers.shp: Shapefiles containing observed SWOT volume anomalies joined to SWORD shapefiles for visualization in each region, with an “is_outlier” flag resulting from the outlier analysis.

/Insitu_valid/



Ext_Fig3_Valid_GRDC_global_corr_interp.xlsx: File containing correlation analysis between SWOT volume anomalies and in situ GRDC gauge data.

/GRDC_stats/1147010_Q_LTVM.csv: files containing the in situ GRDC gauge statistics for comparison.

/GRDC_Watersheds_shp/: folder containing the information and vector files about the in situ GRDC gauges and their associated drained areas.



/Sensitivity_analysis/



wse05w30/: Folder containing /EIV_fits/, /V_EIV/, /V_anom/, and /MeanDRS_slice/ folders from alternate scenario 1 (WSE_u =0.5 m and W_u = 30 m) for the ten studied basins.

wse01w300/: Folder containing /EIV_fits/, /V_EIV/, /V_anom/, and /MeanDRS_slice/ folders from alternate scenario 2 (WSE_u =0.1 m and W_u = 300 m) for the ten studied basins.

wse05w300/: Folder containing /EIV_fits/, /V_EIV/, /V_anom/, and /MeanDRS_slice/ folders from alternate scenario 3 (WSE_u =0.5 m and W_u = 300 m) for the ten studied basins.

sensitivity_uncert.xlsx: Summary file containing the SWOT volume anomalies and their uncertainties in the three degraded scenarios for the ten studied basins.



/global_summary/



/MeanDRS_comp/



Ext_Fig6_V_MeanDRS_comp_means_top20[…].xlsx: File containing data underlying Extended Data Fig. 6, i.e., monthly and annual range comparison between SWOT (and their uncertainties) and MeanDRS volume anomalies.

/regional/V_MeanDRS_comp_means_pfaf_ii_2023-10-01_2024-09-30.csv: Files containing aggregated SWOT (main, low and high) and MeanDRS volume anomalies for comparison in each region.

/global/MeanDRS_comp_global_summary.csv: Files containing aggregated SWOT (main, low and high) and MeanDRS volume anomalies for comparison globally.



/MeanDRS_scale/



/regional/V_MeanDRS_scale_means_pfaf_ii_2023-10-01_2024-09-30.csv: Files containing aggregated scaled SWOT and MeanDRS volume anomalies in each region.

/global/MeanDRS_scale_global_summary.csv: Files containing aggregated scaled SWOT and MeanDRS volume anomalies globally.



/MeanDRS_slice/



/MeanDRS_slice_global_summary.csv: File containing globally aggregated annual slices of MeanDRS volume anomalies for comparison to SWOT (main, low and high).



/MeanDRS_agree/



/MeanDRS_agree_global_mag_ratio.csv: File containing statistics related to the agreement of SWOT and MeanDRS volume anomalies by differences in the magnitude of variability.

/MeanDRS_agree_global_corr.csv: File containing statistics related to the agreement of SWOT and MeanDRS volume anomalies by correlation.








The input testing files consist of a reduced inputs for a select basin (Pfaf 11) used for continuous integration testing of analysis scripts through GitHub. These files are not intended for use outside of CI testing.



input_testing.zip: Input files corresponding to reduced set of SWORD reaches used for GitHub Continuous Integration testing. Not used in primary analysis.


The output testing files consist of a full set of outputs for a select basin (Pfaf 11) used for continuous integration testing of analysis scripts through GitHub. These files are not intended for use outside of CI testing.



output_testing.zip: Output files corresponding to reduced set of SWORD reaches used for GitHub Continuous Integration testing. Not used in primary analysis.