Basin-Scale Variational Hydrological–Hydraulic Model Calibration for River Discharge Estimation Using SWOT Altimetry

submitted to WRR on 13/01/2026

Pujol., L., Garambois., P.-A., Larnier, K., Monnier, J.(submitted) Basin-Scale Variational Hydrological–Hydraulic Model Calibration for River Discharge Estimation Using SWOT Altimetry

hydraulics, hydrology, DassFlow 1D, SMASH, variational data assimilation, swot, altimetry, discharge, double regionalization


smash v1.0: a differentiable and regionalizable high-resolution hydrological modeling and data assimilation framework


doi.org/10.5194/gmd-18-7003-2025

François Colleoni, Ngo Nghi Truyen Huynh, Pierre-André Garambois, Maxime Jay-Allemand,
Didier Organde, Benjamin Renard, Thomas De Fournas, Apolline El Baz, Julie Demargne,
and Pierre Javelle. (2025) SMASH v1.0: A Differentiable and Regionalizable High-Resolution
Hydrological Modeling and Data Assimilation Framework. Geosc. Model Dev. https://doi.
org/10.5194/egusphere-2025-690

hydrology, SMASH, differentiable, regionalizable, varaitional data assimilation


A distributed hybrid physics–AI framework for learning corrections of internal hydrological fluxes and enhancing high-resolution regionalized flood modeling


https://doi.org/10.5194/hess-29-3589-2025, 2025

Huynh, N. N. T., Garambois, P.-A., Renard, B., Colleoni, F., Monnier, J., and Roux, H.: A distributed hybrid physics–AI framework for learning corrections of internal hydrological fluxes and enhancing high-resolution regionalized flood modeling, Hydrol. Earth Syst. Sci., 29, 3589–3613, https://doi.org/10.5194/hess-29-3589-2025, 2025

hydrology, SMASH, physics AI, learnable


Assessing SWOT’s Hydraulic Visibility on the Rhine: Precision Flow Lines and Slope-Based Flood Wave Propagation Signatures


https://doi.org/10.1029/2025EA004309

Ledauphin T., Garambois P.-A., Larnier K., Azzoni M., Emery C., Picot N., Amzil S., Fjortoft
R., Maxant J., Yesou H. (2025) Assessing SWOT’s Hydraulic Visibility on the Rhine: Precision
Flow Lines and Slope-Based Flood Wave Propagation Signatures. Earth and Space Science Data
https://doi.org/10.1029/2025EA004309

SWOT, hydraulic visibility, validation, Rhine


Learning Regionalization within a Differentiable High-Resolution Hydrological Model using Accurate Spatial Cost Gradients


https://doi.org/10.1029/2024WR037544

Huynh, T., Garambois P.-A, Colleoni F., Renard, B., Roux, H., Demargne J., Jay-Allemand M., Javelle P. (2024) Learning Regionalization within a Differentiable High-Resolution Hydrological Model using Accurate Spatial Cost Gradients. Water Ressources Research. https://doi.org/10.1029/2024WR037544

hydrology, SMASH, ungauged basins, regionalization, physics-AI, learning


Multi‐Satellite Data Assimilation for Large‐Scale Hydrological‐Hydrodynamic Prediction: Proof of Concept in the Amazon Basin


https://doi.org/10.1029/2024WR037155

Correa, S. W., Paiva, R. C. D. D., Siqueira, V. A., Papa, F., Fleischmann, A. S., Biancamaria, S., … & Al Bitar, A. (2024). Multi‐Satellite Data Assimilation for Large‐Scale Hydrological‐Hydrodynamic Prediction: Proof of Concept in the Amazon Basin. Water resources research. Vol. 60, no. 8 (Aug. 2024),[Article] e2024WR037155, p. 1-34.

Assimilation; MGB; EO datasets; hydrodynamic


Strengthening of the hydrological cycle in the Lake Chad Basin under current climate change


https://doi.org/10.1038/s41598-024-75707-4

Sylvestre, F., Mahamat-Nour, A., Naradoum, T., Alcoba, M., Gal, L., Paris, A., … & Gaya, D. (2024). Strengthening of the hydrological cycle in the Lake Chad Basin under current climate change. Scientific Reports, 14(1), 24639.

Chad lake; climate change


Estimating channel parameters and discharge at river network scale using hydrological-hydraulic models, SWOT and multi-satellite data


doi:10.1029/2024WR038455

Larnier, K., Garambois, P.-A., Emery, C., Pujol, L., Monnier, J., Gal, L., et al. (2025). Estimating channel parameters and discharge at river network scale using hydrological-hydraulic models, SWOT and multi-satellite data. Water Resources Research, 61, e2024WR038455. https://doi.org/10.1029/2024WR038455

Hydrology, Hydraulics, coupling, Maroni, Data Assimilation, Data Fusion, Altimetry, SWOT


Gaussian Anamorphosis for Ensemble Kalman Filter Analysis of SAR-Derived Wet Surface Ratio Observations


doi:10.1109/TGRS.2023.3338296

Nguyen, T-H., Ricci, S., Piacentini, A., Simon, E., Rodriguez Suquet, R. and Pena Luque, S. (2023) Gaussian Anamorphosis for Ensemble Kalman Filter Analysis of SAR-Derived Wet Surface Ratio Observations, IEEE Transactions on Geoscience and Remote Sensing, 62 (1-21), doi:10.1109/TGRS.2023.3338296


Multi-dimensional hydrological–hydraulic model with variational data assimilation for river networks and floodplains


doi.org/10.5194/gmd-15-6085-2022

Pujol, L., Garambois, P. A., & Monnier, J. (2022). Multi-dimensional hydrological–hydraulic model with variational data assimilation for river networks and floodplains. Geoscientific Model Development, 15(15), 6085-6113.

hydraulics, DassFlow 2D, GR4H, hydrology, multi-dimensional model, variational data assimilation


ExtractEO, a Pipeline for Disaster Extent Mapping in the Context of Emergency Management


https://doi.org/10.3390/rs14205253

Maxant, J.; Braun, R.; Caspard, M.; Clandillon, S. ExtractEO, a Pipeline for Disaster Extent Mapping in the Context of Emergency Management. Remote Sens. 2022, 14, 5253. https://doi.org/10.3390/rs14205253


Improvement of Flood Extent Representation with Remote Sensing Data and Data Assimilation


https://doi.org/10.1109/TGRS.2022.3147429

Nguyen, T-H., Ricci, S., Fatras, C., Piacentini, A., Delmotte, A., Lavergne, E. and Kettig, P. (2022) Improvement of Flood Extent Representation with Remote Sensing Data and Data Assimilation, IEEE Transactions on Geoscience and Remote Sensing, 60 (4206022), pp. 1-22, doi:10.1109/TGRS.2022.3147429

Floodextent, Hydrodynamics, Garonne, Telemac, Data Assimilation, Sentinel1


Dual State-Parameter Assimilation of SAR-Derived Wet Surface Ratio for Improving Fluvial Flood Reanalysis


https://doi.org/10.1029/2022WR033155

Nguyen, T-H., Ricci, S., Piacentini, A., Fatras, C., Kettig, P., Blanchet, G., Peña-Luque, S. and Baillarin, S. (2022) Dual State-Parameter Assimilation of SAR-Derived Wet Surface Ratio for Improving Fluvial Flood Reanalysis, Water Resources Research, 58 (11), pp. e2022WR033155, doi:10.1029/2022WR033155.

Floodextent, Hydrodynamics, Garonne, Telemac, Data Assimilation, Sentinel1


Generation and analysis of stage-fall-discharge laws from coupled hydrological-hydraulic river network model integrating sparse multi-satellite data


https://doi.org/10.1016/j.jhydrol.2021.126993

Malou T., P.-A. Garambois, A. Paris, J. Monnier, K. Larnier. (2021) Generation and analysis of stage-fall-discharge laws from coupled hydrological-hydraulic river network model integrating sparse multi-satellite data. Journal of Hydrology, https://doi.org/10.1016/j.jhydrol.2021.126993


River discharge and bathymetry estimation from SWOT altimetry measurements


https://doi.org/10.1080/17415977.2020.1803858

Larnier, K., Monnier, J., Garambois, P.-A., Verley, J. (2020) « River discharge and bathymetry estimation from SWOT altimetry measurements ». Inverse Problems in Science and Engineering (IPSE). https://doi.org/10.1080/17415977.2020.1803858

hydraulics, DassFlow 1D, variational data assimilation, discharge algorithm, swot


Estimation of multiple inflows and effective channel by assimilation of multi-satellite hydraulic signatures: The ungauged anabranching Negro river


doi.org/10.1016/j.jhydrol.2020.125331

Pujol, L., Garambois, P. A., Finaud-Guyot, P., Monnier, J., Larnier, K., Mose, R., … & Calmant, S. (2020). Estimation of multiple inflows and effective channel by assimilation of multi-satellite hydraulic signatures: The ungauged anabranching Negro river. Journal of Hydrology, 591, 125331.

hydraulics, DassFlow 1D, MGB, variational data assimilation, swot, identifiability maps


Variational estimation of effective channel and ungauged anabranching river discharge from multi-satellite water heights of different spatial sparsity


https://doi.org/10.1016/j.jhydrol.2019.124409

Garambois, P.-A., Larnier, K., Monnier, J., Finaud-Guyot, P., Verley, J., Montazem, A. S., Calmant, S. (2020). « Variational estimation of effective channel and ungauged anabranching river discharge from multi-satellite water heights of different spatial sparsity ». Journal of Hydrology, https://doi.org/10.1016/j.jhydrol.2019.124409

hydraulics, DassFlow 1D, variational data assimilation, discharge algorithm, swot, nadir altimetry, imagery


On the Assimilation of Altimetric Data in 1D Saint-Venant River Flow Models


https://doi.org/10.1016/j.advwatres.2018.06.004

Brisset, P., Monnier, J., Garambois, P.-A., Roux, H. (2018). « On the Assimilation of Altimetric Data in 1D Saint-Venant River Flow Models ». Advances in Water Ressources. https://doi.org/10.1016/j.advwatres.2018.06.004

hydraulics, DassFlow 1D, variational data assimilation, swot, frequencies, identifiability maps


Modelling hydrologic and hydrodynamic processes in basins with large semi-arid wetlands


https://doi.org/10.1016/j.jhydrol.2018.04.041

Fleischmann, A., Siqueira, V., Paris, A., Collischonn, W., Paiva, R., Pontes, P., … & Tanimoun, B. (2018). Modelling hydrologic and hydrodynamic processes in basins with large semi-arid wetlands. Journal of Hydrology, 561, 943-959.

modelling; MGB; hydrology; hydrodynamic


Inverse algorithms for 2D shallow water equations in presence of wet dry fronts: Application to flood plain dynamics


https://doi.org/10.1016/j.advwatres.2016.07.005, 2016

Monnier, J., Couderc, F., Dartus, D., Larnier, K., Madec, R., and Vila, J.-P.: Inverse algorithms for 2D shallow water equations in presence of wet dry fronts: Application to flood plain dynamics, Adv. Water Resour., 97, 11–24,https://doi.org/10.1016/j.advwatres.2016.07.005, 2016.

Hydraulics, finite volumes, DassFlow 2D, variational data assimilation, flooding, parameters inferrence


Stage-discharge rating curves based on satellite altimetry
and modeled discharge in the Amazon basin


https://doi.org/10.1002/2014WR016618

Paris, A., Dias de Paiva, R., Santos da Silva, J., Medeiros Moreira, D., Calmant, S., Garambois, P.-A.,  Seyler, F . (2016). Stage-discharge rating curves based on satellite altimetry and modeled discharge in the amazon basin. Water Resources Research, 52 (5), 3787-3814.

Hydrology, MGB, altimetry, discharge, rating curves


Monitoring Hydrological Variables from Remote Sensing and Modeling in the Congo River Basin


https://doi.org/10.1002/9781119657002.ch18


https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1002/9781119657002.ch18

Paris, A., Calmant, S., Gosset, M., Fleischmann, A. S., Conchy, T. S. X., Garambois, P. A., … & Laraque, A. (2022). Monitoring hydrological variables from remote sensing and modeling in the Congo River Basin. Congo basin hydrology, climate, and biogeochemistry: a foundation for the future, 339-366.

modelling; mgb; hydrology; EO datasets; altimetry