690 / 2024-09-19 08:39:48

Enhancing Sediment Model by Incorporating Spatial-Temporal Variability in Particle Size and Settling Velocity Using Machine Learning Coupled with Numerical Models

Machine Learning; sediment modelling; sediment flocculation; settling velocity; remote sensing; in-situ measurement

Session 24 - Estuaries and coastal environments stress - Observations and modelling

Accurate prediction of sediment settling is critical for management of coastal ecosystems, but complex estuarine processes that influence sediment deposition and erosion present a major modelling challenge. This study explores a more efficient approach to simulating how particle size changes with dynamic sediment flocculation and thereby determines settling velocity. Environmental controls on in-situ particle size (median particle size D₅₀) were investigated using regression model trained on coeval measurements of salinity, shear rate, and suspended sediment concentration (SSC). A machine learning (ML) model was developed and integrated into a fully coupled current-wave-sediment model to simulate flocculation-dimensional response in particle size due to variations in shear rate, salinity and SSC. The integrated model framework demonstrates its reliability and accuracy when evaluated against the in-situ measurements, SSC derived from satellite observations, and a parametric flocculation model that only relates settling velocity to SSC.