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ORIGINAL RESEARCH article

Front. Remote Sens.
Sec. Terrestrial Water Cycle
Volume 5 - 2024 | doi: 10.3389/frsen.2024.1466695

First results of the Surface Water Ocean Topography (SWOT) observations to rivers elevation profiles in the Cuvette Centrale of the Congo Basin

Provisionally accepted
Cassandra Normandin Cassandra Normandin 1*Frédéric Frappart Frédéric Frappart 1Nicolas Baghdadi Nicolas Baghdadi 2,3Luc BOURREL Luc BOURREL 4Santiago P. Luque Santiago P. Luque 5Bertrand Ygorra Bertrand Ygorra 1Benjamin Kitambo Benjamin Kitambo 6,7,8Fabrice Papa Fabrice Papa 6Serge Riazanoff Serge Riazanoff 9Jean-Pierre Wigneron Jean-Pierre Wigneron 1
  • 1 INRAE ​​Nouvelle-Aquitaine Bordeaux, Bordeaux, France
  • 2 INRAE Occitanie Montpellier, Montpellier, Languedoc-Roussillon, France
  • 3 UMR9000 Territoires, Environnement, Télédétection et Information Spatiale (TETIS), Montpellier, Languedoc-Roussillon, France
  • 4 UMR5563 Géosciences Environnement Toulouse (GET), Toulouse, Midi-Pyrénées, France
  • 5 Centre National d’Etudes Spatiales (CNES), Paris, France
  • 6 UMR5566 Laboratoire d'études en géophysique et océanographie spatiales (LEGOS), Toulouse, Midi-Pyrénées, France
  • 7 Faculty of sciences Democratic Republic of Congo, Lubumbashi, Democratic Republic of Congo
  • 8 Congo Basin Water Resources Research Center (CRREBaC), Kinshasa, Democratic Republic of Congo
  • 9 Visio Terra, Champs-sur-Marne, France

The final, formatted version of the article will be published soon.

    Rivers play a crucial role in maintaining ecosystems and regional climates, while also providing essential water for irrigation and drinking. With the increasing impacts of climate change and human activities, rivers are becoming more prone to extreme events (droughts and floods) and induced erosion/deposition processes, making water-related risk management more challenging. The recent launch of the Surface Water and Ocean Topography (SWOT) mission, which focuses on continental surfaces with a spatial resolution of 100 meters, has opened new avenues for applications in hydrology, hydrodynamics, and geomorphology. This study examines the initial results of the SWOT mission for sixteen16 rivers (ranging in width from 50 to 2000 meters) in the Cuvette Centrale of the Congo Basin, obtained in April 2023 during the fast sampling phase. The study assesses water surface elevations (WSE) and backscatter coefficient (σ0) measured from SWOT. Comparisons of WSE with data from conventional other radar altimetry missions (Sentinel-3A and 3B, Jason-3, and Sentinel-6A) and GEDI data show high correlation coefficients of 0.977 (with a bias of 0.538 m) and 0.992 (with a bias of 1.011 m), respectively. The first maps of WSE slopes show realistic values, even in rivers less than 100 meters wide, with steeper slopes upstream. Various WSE longitudinal profiles are retrieved with unprecedented spatial resolution, surpassing what conventional other nadir altimetry missions have achieved. The σ0 values, between -10 and 20 dB on average, also appear consistent with other studies. These promising initial results pave the way for future studies on fluvial geomorphology dynamics and erosion/deposition processes from the new SWOT observations. Mis en forme : Indice Mis en forme : Indice Mis en forme : Indice Mis en forme : Indice Mis en forme : Indice Mis en forme : Indice Mis en forme : Indice Mis en forme : Indice Mis en forme : Indice Mis en forme : Indice Mis en forme : Indice Mis en forme : Indice Mis en forme : Indice Mis en forme : Indice Mis en forme : Indice Mis en forme : Indice

    Keywords: SWOT mission, Rivers, water surface elevation, Backscattering coefficient, Cuvette Centrale, Congo basin

    Received: 18 Jul 2024; Accepted: 27 Sep 2024.

    Copyright: © 2024 Normandin, Frappart, Baghdadi, BOURREL, Luque, Ygorra, Kitambo, Papa, Riazanoff and Wigneron. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

    * Correspondence: Cassandra Normandin, INRAE ​​Nouvelle-Aquitaine Bordeaux, Bordeaux, France

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