Long-term, process-based morphodynamic modeling of a fluvio-deltaic system, part I: The role of river discharge

摘要

Tidal basin and delta morphodynamics have been broadly examined by numerical modeling efforts, but large scale estuarine morphodynamics under combined river and tidal forcing have been less examined. This study aims to explore morphodynamic development of a river- and tide-forced fluvio-deltaic system using a 2DH process-based numerical model (Delft3D). The model domain describes a 560 km long, convergent inner basin attached to a > 50 km wide outer sea basin allowing for delta formation. Longterm (millennial) morphodynamic simulation is aided by a morphological factor approach which captures the feedback mechanisms between water motion, sediment movement, and morphology. The morphodynamic sensitivities to river discharge magnitude and its seasonal variations are systematically examined.