The doi above is for this specific version of this dataset, which is currently the latest. Newer versions may be published in the future. For a link that will always point to the latest version, please use
doi: 10.4121/0c6be5a5-2294-4f16-b2ff-cb9ef4826402

de Lange, Sjoukje (2023): Replication Dataset for "Dune geometry and the associated hydraulic roughness in a fluvial to tidal transition zone at low river flow". Version 1. 4TU.ResearchData. dataset. https://doi.org/10.4121/0c6be5a5-2294-4f16-b2ff-cb9ef4826402.v1

Dataset

• Physical Geography and Environmental Geoscience
• Earth Sciences

Fluvial-to-tidal transition zone, Fraser River, hydraulic roughness, subaqueous bedforms

2017-2021

CC BY 4.0

RefWorks, BibTeX, Reference Manager, Endnote, DataCite, NLM, DC, CFF

by Sjoukje de Lange

Replication dataset corresponding to the publication "Dune geometry and the associated hydraulic roughness in a fluvial to tidal transition zone at low river flow"

This dataset consists of the raw field data, hydraulic model, processed field data and scripts. The contents are described in the word document.

Abstract:

 In deltas and estuaries throughout the world, a fluvial-to-tidal transition zone (FTTZ) exists where both the river discharge and the tidal motion drive the flow. It is unclear how dune characteristics are impacted by changes in tidal flow strength, and how this is reflected in the hydraulic roughness. To understand dune geometry and variability in the FTTZ and possible impacts on hydraulic roughness, we assess dune variability from multibeam bathymetric surveys, and we use a calibrated 2D hydrodynamic model (Delft3D-FM) of a sand-bedded lowland river (Fraser River, Canada). We focus on a period of low river discharge during which tidal impact is strong. We find that the fluvial-tidal to tidal regime change is not directly reflected in dune height, but local patterns of increasing and decreasing dune height are present. The fluvial-to-tidal regime change is reflected in dune shape, where dunes have lower leeside angles and are more symmetrical in the tidal regime. The calibrated model is able to estimate local patterns of dune heights using tidally-averaged values of bed shear stress. However, the spatially variable dune morphology hampers local dune height estimations. Changes in dune shape do not significantly impact the reach-scale roughness, and estimated dune roughness using dune height and length is similar to the dune roughness inferred from model calibration. Hydraulic model performance with a calibrated, constant roughness is not improved by implementing dune-derived bed roughness. Instead, large-scale river morphology may explain differences in model roughness and corresponding estimates from dune predictors.

• 2023-11-06 first online, published, posted

4TU.ResearchData

3D3 model data, mdu, xlsx, txt, png, mat, m, docx

• Netherlands Organization for Scientific Research (NWO), within Vici project “Deltas out of shape: regime changes of sediment dynamics in tide-influenced deltas” (Grant NWO-TTW 17062)

Wageningen University, Department of Environmental Sciences, Hydrology and Quantitative Water Management, Wageningen, the Netherlands
Northwest Hydraulic Consultants Ltd., North Vancouver, British Columbia, Canada
School of Environmental Science, Simon Fraser University, Burnaby, British Columbia, Canada