pyRiverBed: A Python framework to generate synthetic riverbed topography of constant-width meandering rivers

See paper on the publisher’s site: https://doi.org/10.1016/j.cageo.2021.104755

Highlights

• We propose a Python-based model to generate bed topography for meandering rivers.

• The model can work on the Kinoshita curve-defined idealized meandering channels.

• The model can load user-provided real-world meandering channel centerlines.

• The model can generate finite element mesh file for flow and sediment simulations.

• The model integrates a meander migration and neck cutoff detection submodel.

Abstract

Meandering is one of the unique processes in Earth surface dynamics. Since the 1960s, fluvial geomorphologists have generalized numerous widely-acknowledged empirical or semi-empirical formulae to describe meandering rivers’ characteristics. The most frequently applied one is the Kinoshita high-sinuosity curve to describe meander channel planform geometry. Combining the Kinoshita curve with the Beck equations to describe the riverbed topography at equilibrium state, a prototype of a synthetic riverbed topography generating model is made for idealized meandering rivers. Such a method can be readily extended and applied to arbitrary meandering rivers in the real world, resulting in the synthetic riverbed topography model, pyRiverBed, presented herein. A meander migration and neck cutoff submodel is also embedded in pyRiverBed. Unlike existing linear and non-linear bend theory-based models, pyRiverbed aims towards generating the riverbed topography for each snapshot during the migration process. The present model can facilitate meandering river researchers to interpolate their field-measured bathymetric data using the synthetic bed, design their non-flat bed laboratory flumes for experiments, and initialize their hydrodynamic and morphodynamic numerical models. It can also provide guidance in stream restoration projects on designing a channel with a morphodynamic equilibrium bed. The quality of generated synthetic bed topography is evaluated through the comparison against both laboratory experiment data and field-measured data. The meander migration submodel is validated using a real-world channel migration and neck cutoff event. The validation results prove that the synthetic riverbed’s accuracy is reasonably good, and the meander migration submodel can successfully predict meander migration and neck cutoff.