Integrated monitoring of suspended sediment transport in a transboundary river basin: Insights into sediment fluxes and reservoir effects in the Thaya catchment

Sediment transport plays a key role in riverine processes and water quality regulation, yet remains challenging to quantify, particularly in transboundary and regulated catchments. This study presents a coordinated, long-term monitoring approach across eight stations in the Thaya River basin (Austria and Czech Republic), combining turbidity sensors, flow data, and manual sampling. Relationships between turbidity and suspended sediment concentration were established through site-specific regression, with R² values exceeding 0.95 at three stations. Results revealed pronounced spatial variability in sediment loads, driven by land use, reservoir trapping, and tributary inputs. The Vranov, Znojmo and Nové Mlýny reservoirs significantly reduced sediment transport, although downstream recovery occurred due to tributary inflows. Maintenance requirements, sensor fouling, and deployment geometry strongly influenced data reliability, underscoring the need for standardized protocols in multi-site networks. The dataset enhances sediment budget estimation and reservoir sedimentation forecasts, supporting adaptive catchment-scale sediment management and meeting European water policy objectives.