As the largest river basin on Earth, the Amazon is of great importance to the world’s climate and water resources.
The understanding of several hydrological processes was only possible with the advent of remote sensing observations, such as the characterization of “rainfall hotspots” in the Andes-Amazon transition, evapotranspiration rates and variations of surface waters and groundwater storage.
The high rates of precipitation, evapotranspiration and large variations in fresh water storage are river discharge make the Amazon basin a key player in the global climate system, with large contributions to the energy, water and carbon cycles. Amazon surface waters, for example, are a major source and sink of carbon dioxide.
The region is now facing risks under climate and anthropogenic changes, and changes in Amazon hydrology could have significant impacts globally.
Understanding the dynamics of the Amazon water cycle is of primary importance for climate and ecology research and for the management of water resources.
The understanding of Amazon hydrology coevolved with another groundbreaking field: the remote sensing (RS) of the terrestrial water cycle. The Amazon basin has been an ideal natural laboratory for the seminal development of RS techniques with the advent of Earth observations (EO) and these advances have fostered the scientific understanding of Amazon hydrology, ecosystems, and environmental changes. For example, the first applications of gravimetric and altimeter satellites to characterize, respectively, surface water elevation and total water storage variations were performed in the basin due to its wide river and large spatial and temporal changes of freshwater. Pioneering RS applications also include synthetic-aperture radar (SAR), microwave and interferometric mapping of large-scale flood inundation and characterization of sediment dynamics
https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2020RG000728