Spatial and temporal variation of water reflectance in an Amazonian estuary: a case study around Tatuoca Island

This study presents the first long-term hydro-sediment balance of the Ucayali River using observations, remote sensing, and SWAT-Amazon. The river exports 455 Mt yr⁻¹ of sediment, 36 % trapped in the floodplain. Floodplain recycling contributes 22 %, while a newly identified sand deposition process during floods decouples sediment from water fluxes. The study highlights the need for robust hydrological networks and regional assessments to better capture Amazonian sediment dynamics.