Evaluation of SWOT Water Surface Elevation Product Along the Middle Paraná River

Water surface elevation (WSE) estimation is crucial for understanding hydrological processes and managing water resources. Remote sensing observations play a vital role in consistently estimating WSE over large areas. In this context, the new Surface Water and Ocean Topography (SWOT) mission equipped with Synthetic Aperture Radar (SAR) technology, offers the opportunity to monitor WSE and other crucial parameters with high spatial resolutions. The Paraná River stands out because it is the second-longest river system in South America. Hence, the performance of the SWOT product was evaluated using in situ WSE observations in this area. Specifically, SWOT estimates were compared with WSE measurements registered by four gage stations (Paraná, Colastiné, Leyes, and Santa Fe) for 01/2024-04/2024. The results show that SWOT estimates agree well with observed WSE data, with uncertainties lower than 6% and a determination coefficient (R2) greater than 0.96. Moreover, the SWOT product accurately reproduces the temporal variation as in situ WSE measurements over the period and selected stations. These initial results are very promising, highlighting the potential of this new mission to accurately monitor WSE with high spatial resolution.