Journal Article

Widespread and Exceptional Reduction in River Water Levels Across the Amazon Basin During the 2023 Extreme Drought Revealed by Satellite Altimetry and SWOT

Mamirauá Institute for Sustainable Development = Instituto de Desenvolvimento Sustentavel Mamirauá (IDSM), Companhia de Pesquisa de Recursos Minerais (CPRM) ; Serviço Geológico do Brasil (SGB), Universidade de Brasilia = University of Brasilia [Brasília] (UnB), Interactions Sol Plante Atmosphère (UMR ISPA) ; Ecole Nationale Supérieure des Sciences Agronomiques de Bordeaux-Aquitaine (Bordeaux Sciences Agro)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Moreira, Daniel, Laboratoire d'études en Géophysique et océanographie spatiales (LEGOS) ; Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Université de Toulouse (EPE UT) ; Communauté d'universités et établissements de Toulouse (Comue de Toulouse)-Communauté d'universités et établissements de Toulouse (Comue de Toulouse), Fassoni‐andrade, Ali

2025

Overview

In late 2023, the Amazon River Basin experienced its most extreme drought to date, putting its population and ecosystem at risk. Gauges that were still functioning measured the lowest river water levels (RWL) on record. Here, satellite observations, including Surface Water Ocean Topography (SWOT), reveal the spread and timing of extremely low RWL across the entire river system. The majority of Nadir altimeter observations show that the 2023 minimum RWL in the Central Amazon were 3 m or more below their annual average, representing two to three times its mean variability. Additionally, SWOT captures the basin-scale reduction in RWL with a spatial resolution of 200 m and how it propagates with time. Large-scale evaluation with gauges suggests that SWOT outperforms classical altimetry in estimating RWL, despites differences that need further investigations. SWOT offers a new opportunity to understand hydroclimatic extremes and their broad impacts on the environment of the Amazon.

• Publisher: American Geophysical Union,CCSD,John Wiley & Sons, Inc
• Subject: Altimeters / Altimetry / Amazon River Basin / Climate change / Drought / Environmental impact / Environmental Sciences / Extreme drought / extreme event / Gauges / Hydrologic cycle / Hydrology / River basins / River water / Rivers / Satellite altimetry / Satellite observation / Satellites / Spatial discrimination / Spatial resolution / Surface water / SWOT / Water levels
• ISBN: 0015042109000