Implementation of geotechnical and vegetation modules in TELEMAC to simulate the dynamics of vegetated alluvial floodplains

Y. Y. Rousseau, Marco J. Van de Wiel, P. M. Biron

Research output: Chapter in Book/Report/Conference proceedingConference proceeding

27 Downloads (Pure)

Abstract

Amongst the most widely used computational fluid dynamics models, some include a sediment transport module that enables the examination of river channel dynamics. However, most ignore two families of processes influencing lateral erosion rates, and thus channel evolution mechanisms: lateral transport of sediment through mass wasting along river banks and valley walls, and soil reinforcement created by plant roots. A few modelling packages consider geotechnical processes, albeit with important limitations. Indeed, most solutions are solely compatible with single-threaded channels, impose a given computational mesh structure (e.g. body-fitted coordinate system), derive lateral migration rates from hydraulic properties, adjust bank morphology solely based on the angle of repose of the bank material, rely on non-physical assumptions to describe certain processes (e.g. channel cut offs in meandering rivers), and exclude floodplain processes. This paper describes the development and testing of two modules that were recently added to the mathematical suite of solvers TELEMAC-MASCARET to address the aforementioned limitations. The first module (GEOTECH) includes an algorithm that scans the computational domain in an attempt to detect potentially unstable slope profiles across the domain or intersecting with water-soil boundaries. The module relies on a fully configurable, universal genetic algorithm with tournament selection to delineate the shape of the surface along which a slump block detaches itself from a river bank or slope by translational or rotational mechanism. Both the hydrostatic pressure caused by the flow and the elevation of the water table are used in the Bishop’s method to quantify slope stability. Another algorithm computes the surface of the coarse fraction of the block material which is deposited at the toe of the slope. The second module (RIPVEG) simulates the evolution of floodplain vegetation, whose properties affect the geotechnical stability of slopes present in the computational domain by imposing a surcharge and increasing soil cohesion near the soil surface. Plants develop in height, weight and rooting depth at a rate that depends on the species and plant age. The two modules, combined with the flow and sediment transport models included in TELEMAC, provide a holistic solution to study the dynamics of a broad range of alluvial river types. The model is currently being tested, calibrated and validated using datasets from meandering rivers.
Original languageEnglish
Title of host publicationProceedings of the XXIst TELEMAC-MASCARET User Conference held in Grenoble in October 2014
Pages169-177
Number of pages8
Publication statusPublished - 2014
EventTelemac-Mascaret User Conference - Grenoble, France
Duration: 15 Oct 201417 Oct 2014

Conference

ConferenceTelemac-Mascaret User Conference
CountryFrance
CityGrenoble
Period15/10/1417/10/14

Fingerprint

floodplain
sediment transport
vegetation
river
soil reinforcement
mass wasting
river bank
river channel
hydraulic property
rooting
cohesion
soil water
sediment
soil
material
family
rate
method

Cite this

Rousseau, Y. Y., Van de Wiel, M. J., & Biron, P. M. (2014). Implementation of geotechnical and vegetation modules in TELEMAC to simulate the dynamics of vegetated alluvial floodplains. In Proceedings of the XXIst TELEMAC-MASCARET User Conference held in Grenoble in October 2014 (pp. 169-177)

Implementation of geotechnical and vegetation modules in TELEMAC to simulate the dynamics of vegetated alluvial floodplains. / Rousseau, Y. Y.; Van de Wiel, Marco J.; Biron, P. M.

Proceedings of the XXIst TELEMAC-MASCARET User Conference held in Grenoble in October 2014. 2014. p. 169-177.

Research output: Chapter in Book/Report/Conference proceedingConference proceeding

Rousseau, YY, Van de Wiel, MJ & Biron, PM 2014, Implementation of geotechnical and vegetation modules in TELEMAC to simulate the dynamics of vegetated alluvial floodplains. in Proceedings of the XXIst TELEMAC-MASCARET User Conference held in Grenoble in October 2014. pp. 169-177, Telemac-Mascaret User Conference, Grenoble, France, 15/10/14.
Rousseau YY, Van de Wiel MJ, Biron PM. Implementation of geotechnical and vegetation modules in TELEMAC to simulate the dynamics of vegetated alluvial floodplains. In Proceedings of the XXIst TELEMAC-MASCARET User Conference held in Grenoble in October 2014. 2014. p. 169-177
Rousseau, Y. Y. ; Van de Wiel, Marco J. ; Biron, P. M. / Implementation of geotechnical and vegetation modules in TELEMAC to simulate the dynamics of vegetated alluvial floodplains. Proceedings of the XXIst TELEMAC-MASCARET User Conference held in Grenoble in October 2014. 2014. pp. 169-177
@inproceedings{99ca2495e0414b759b8d8e6991276eef,
title = "Implementation of geotechnical and vegetation modules in TELEMAC to simulate the dynamics of vegetated alluvial floodplains",
abstract = "Amongst the most widely used computational fluid dynamics models, some include a sediment transport module that enables the examination of river channel dynamics. However, most ignore two families of processes influencing lateral erosion rates, and thus channel evolution mechanisms: lateral transport of sediment through mass wasting along river banks and valley walls, and soil reinforcement created by plant roots. A few modelling packages consider geotechnical processes, albeit with important limitations. Indeed, most solutions are solely compatible with single-threaded channels, impose a given computational mesh structure (e.g. body-fitted coordinate system), derive lateral migration rates from hydraulic properties, adjust bank morphology solely based on the angle of repose of the bank material, rely on non-physical assumptions to describe certain processes (e.g. channel cut offs in meandering rivers), and exclude floodplain processes. This paper describes the development and testing of two modules that were recently added to the mathematical suite of solvers TELEMAC-MASCARET to address the aforementioned limitations. The first module (GEOTECH) includes an algorithm that scans the computational domain in an attempt to detect potentially unstable slope profiles across the domain or intersecting with water-soil boundaries. The module relies on a fully configurable, universal genetic algorithm with tournament selection to delineate the shape of the surface along which a slump block detaches itself from a river bank or slope by translational or rotational mechanism. Both the hydrostatic pressure caused by the flow and the elevation of the water table are used in the Bishop’s method to quantify slope stability. Another algorithm computes the surface of the coarse fraction of the block material which is deposited at the toe of the slope. The second module (RIPVEG) simulates the evolution of floodplain vegetation, whose properties affect the geotechnical stability of slopes present in the computational domain by imposing a surcharge and increasing soil cohesion near the soil surface. Plants develop in height, weight and rooting depth at a rate that depends on the species and plant age. The two modules, combined with the flow and sediment transport models included in TELEMAC, provide a holistic solution to study the dynamics of a broad range of alluvial river types. The model is currently being tested, calibrated and validated using datasets from meandering rivers.",
author = "Rousseau, {Y. Y.} and {Van de Wiel}, {Marco J.} and Biron, {P. M.}",
year = "2014",
language = "English",
pages = "169--177",
booktitle = "Proceedings of the XXIst TELEMAC-MASCARET User Conference held in Grenoble in October 2014",

}

TY - GEN

T1 - Implementation of geotechnical and vegetation modules in TELEMAC to simulate the dynamics of vegetated alluvial floodplains

AU - Rousseau, Y. Y.

AU - Van de Wiel, Marco J.

AU - Biron, P. M.

PY - 2014

Y1 - 2014

N2 - Amongst the most widely used computational fluid dynamics models, some include a sediment transport module that enables the examination of river channel dynamics. However, most ignore two families of processes influencing lateral erosion rates, and thus channel evolution mechanisms: lateral transport of sediment through mass wasting along river banks and valley walls, and soil reinforcement created by plant roots. A few modelling packages consider geotechnical processes, albeit with important limitations. Indeed, most solutions are solely compatible with single-threaded channels, impose a given computational mesh structure (e.g. body-fitted coordinate system), derive lateral migration rates from hydraulic properties, adjust bank morphology solely based on the angle of repose of the bank material, rely on non-physical assumptions to describe certain processes (e.g. channel cut offs in meandering rivers), and exclude floodplain processes. This paper describes the development and testing of two modules that were recently added to the mathematical suite of solvers TELEMAC-MASCARET to address the aforementioned limitations. The first module (GEOTECH) includes an algorithm that scans the computational domain in an attempt to detect potentially unstable slope profiles across the domain or intersecting with water-soil boundaries. The module relies on a fully configurable, universal genetic algorithm with tournament selection to delineate the shape of the surface along which a slump block detaches itself from a river bank or slope by translational or rotational mechanism. Both the hydrostatic pressure caused by the flow and the elevation of the water table are used in the Bishop’s method to quantify slope stability. Another algorithm computes the surface of the coarse fraction of the block material which is deposited at the toe of the slope. The second module (RIPVEG) simulates the evolution of floodplain vegetation, whose properties affect the geotechnical stability of slopes present in the computational domain by imposing a surcharge and increasing soil cohesion near the soil surface. Plants develop in height, weight and rooting depth at a rate that depends on the species and plant age. The two modules, combined with the flow and sediment transport models included in TELEMAC, provide a holistic solution to study the dynamics of a broad range of alluvial river types. The model is currently being tested, calibrated and validated using datasets from meandering rivers.

AB - Amongst the most widely used computational fluid dynamics models, some include a sediment transport module that enables the examination of river channel dynamics. However, most ignore two families of processes influencing lateral erosion rates, and thus channel evolution mechanisms: lateral transport of sediment through mass wasting along river banks and valley walls, and soil reinforcement created by plant roots. A few modelling packages consider geotechnical processes, albeit with important limitations. Indeed, most solutions are solely compatible with single-threaded channels, impose a given computational mesh structure (e.g. body-fitted coordinate system), derive lateral migration rates from hydraulic properties, adjust bank morphology solely based on the angle of repose of the bank material, rely on non-physical assumptions to describe certain processes (e.g. channel cut offs in meandering rivers), and exclude floodplain processes. This paper describes the development and testing of two modules that were recently added to the mathematical suite of solvers TELEMAC-MASCARET to address the aforementioned limitations. The first module (GEOTECH) includes an algorithm that scans the computational domain in an attempt to detect potentially unstable slope profiles across the domain or intersecting with water-soil boundaries. The module relies on a fully configurable, universal genetic algorithm with tournament selection to delineate the shape of the surface along which a slump block detaches itself from a river bank or slope by translational or rotational mechanism. Both the hydrostatic pressure caused by the flow and the elevation of the water table are used in the Bishop’s method to quantify slope stability. Another algorithm computes the surface of the coarse fraction of the block material which is deposited at the toe of the slope. The second module (RIPVEG) simulates the evolution of floodplain vegetation, whose properties affect the geotechnical stability of slopes present in the computational domain by imposing a surcharge and increasing soil cohesion near the soil surface. Plants develop in height, weight and rooting depth at a rate that depends on the species and plant age. The two modules, combined with the flow and sediment transport models included in TELEMAC, provide a holistic solution to study the dynamics of a broad range of alluvial river types. The model is currently being tested, calibrated and validated using datasets from meandering rivers.

M3 - Conference proceeding

SP - 169

EP - 177

BT - Proceedings of the XXIst TELEMAC-MASCARET User Conference held in Grenoble in October 2014

ER -