Braided Rivers From SWOT: Water Surface Dynamics Over the Multi‐Channel Brahmaputra River

The Surface Water and Ocean Topography (SWOT) satellite can simultaneously observe river elevation, width, and slope with high spatio‐temporal coverage and resolution (Fu et al., 2024, https://doi.org/10.1029/2023gl107652). The River Single‐Pass (RiverSP) product from SWOT provides geolocated river surface water dynamics with global coverage, but it utilizes simplified river centerlines that do not properly represent braided rivers. We present a method for integrating high‐resolution pixel cloud SWOT data with Sentinel‐2 multispectral imagery for multi‐channel river analysis, with a case study over the Brahmaputra River. We generate dynamic river centerlines from multispectral river masks and apply SWOT observations to the generated centerlines. We find that refined centerline knowledge allows for improved estimates of river surface water dynamics in braided channels when compared to RiverSP. For the Brahmaputra, we find that water surface elevation can vary by 0.5 m and slope can vary by 2 cm/km between parallel channels of the braided river.