Received: 10 Aug 2018 – Discussion started: 03 Sep 2018
Abstract. Being a widespread source-to-sink sedimentary environment, the fine-grained dispersal system (FGDS) features remarkably high sediment flux, interacting closely with local morphology and ecosystem. Such exceptional transport is believed to be associated with changes in bedform geometry, which further demands theoretical interpretation. Using van Rijn (2007a) bed roughness predictor, we set up a simple numerical model to calculate sediment transport, classify sediment transport behaviors into dune and (mega-)ripple dominant regimes, and discuss the causes of the sediment transport regime shift linked with bedform categories. Both regimes show internally consistent transport behaviors, and the latter, associated with FGDSs, exhibits considerably higher sediment transport rate than the previous. Between lies the coexistence zone, the sediment transport regime shift accompanied by degeneration of dune roughness, which can considerably reinforce sediment transport and is further highlighted under greater water depth. This study can be applied to modeling of sediment transport and morphodynamics.
This preprint has been withdrawn.
How to cite. Zhao, T., Yu, Q., Wang, Y., and Gao, S.: Theoretical Interpretation of the Exceptional Sediment Transport of Fine-grained Dispersal Systems Associated with Bedform Categories, Earth Surf. Dynam. Discuss. [preprint], https://doi.org/10.5194/esurf-2018-64, 2018.
In many coastal, riverine, deltaic, marine, and subglacial systems, plentiful fine bed sediment is produced and moved to change the surface features and surrounding environments along its pathway. Our numerical research shows that, in these systems, weakened bed level changes can reduce bed friction and produce higher sediment yield, whose effects can be amplified under greater water depth. This finding can help predict sediment movement and bed level changes of water channels.
In many coastal, riverine, deltaic, marine, and subglacial systems, plentiful fine bed sediment...