Physical and Numerical Modeling of Submerged Vegetation Roughness in Rivers and Flood Plains

Fathi-Moghadam, Manoochehr; Kashefipour, M; Ebrahimi, N.; Emamgholizadeh, Samad

doi:10.1061/(asce)he.1943-5584.0000381

Cited by 29 publications

(22 citation statements)

References 18 publications

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“…It is worth specifying how the assumption of a lower slope angle (e.g. 10°) would not be a realistic hypothesis for the stone‐wall bench‐terraces of the reference condition (Figure d). Manning's n roughness is uniformly distributed on the DTM and assigned a value of n = 0·125 in the typical range of the overland flow (Fathi‐Moghadam et al ., ); Surface‐water detention equal to 1 mm.…”

Section: Methods and Assumptions For Bench‐terrace Modellingmentioning

confidence: 99%

Performance Assessment of Bench‐Terraces Through 2‐D Modelling

Perlotto

D’Agostino

2016

Land Degrad Dev

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The use of dry‐stone walls to build bench‐terraces has traditionally played a key role in the management of hilly and mountainous agricultural areas. They are typically built to increase suitable crop areas, provide safe working conditions and improve terrain stability during rainfall events. Because the mean gradient is greatly reduced by the presence of bench‐terraces, the hydrological response of a terraced slope should result in a reduction of peak runoff at the toe of a hillslope and a delay in the passage of peak flows. This research develops and quantifies this hypothesis. The FLO‐2D model is used to analyse the runoff propagation mechanism of a terraced slope (sequence of dry‐stone walls) by varying number and spacing of terraces and assuming two hydrological soil setting scenarios in terms of antecedent moisture conditions within the Soil Conservation Service‐Curve Number method. The model analysis shows that the majority of runoff modifications at the outlet of a terraced system result from topographical modifications rather than local hydrological variations at the dry‐stone wall zone. Repeated modelling applications show that, given a quite‐typical scenario of a 20°‐sloped hillslope and a reference intense rainstorm, the peak discharge reduction at the hillslope outlet depends on the percentage of the area managed with terraces. The reduction can be calculated with a logarithmic‐type function (for example, an increase of terraced area from 10% to 30% might bring to runoff peak reduction of almost 45%). This information can help determine where terrace additions are more effective in terms of hydrological benefit. Copyright © 2016 John Wiley & Sons, Ltd.

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Section: Methods and Assumptions For Bench‐terrace Modellingmentioning

confidence: 99%

Performance Assessment of Bench‐Terraces Through 2‐D Modelling

Perlotto

D’Agostino

2016

Land Degrad Dev

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“…While some research groups have studied the effect of submergence ratio with single height vegetation (e.g. Ghisalberti and Nepf, 2002;Järvelä, 2005;Fathi-Moghadam et al, 2011), a more dynamic approach, allowing for exploration of time-dependent submergence ratio, is still lacking.…”

Section: Patch Submergencementioning

confidence: 99%

“…Ghisalberti and Nepf, ; Järvelä, ; Fathi‐Moghadam et al. ), a more dynamic approach, allowing for exploration of time‐dependent submergence ratio, is still lacking.…”

Section: Characterization Of Vegetation Flow and Their Interactions mentioning

confidence: 99%

Simplification bias: lessons from laboratory and field experiments on flow through aquatic vegetation

Tinoco

Juan

Mullarney

2020

Earth Surf Processes Landf

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We present a critical analysis of experimental findings on vegetation-flow-sediment interactions obtained through both laboratory and field experiments on tidal and coastal environments. It is well established that aquatic vegetation provides a wide range of ecosystem services (e.g. protecting coastal communities from extreme events, reducing riverbank and coastal erosion, housing diverse ecosystems), and the effort to better understand such services has led to multiple approaches to reproduce the relevant physical processes through detailed laboratory experiments. State-of-the-art measurement techniques allow researchers to measure velocity fields and sediment transport with high spatial and temporal resolution under well-controlled flow conditions, yielding predictions for hydrodynamic and sediment transport scenarios that depend on simplified or bulk vegetation parameters. However, recent field studies have shown that some simplifications on the experimental setup (e.g. the use of rigid elements, a single diameter, a single element height, regular or staggered layout) can bias the outcome of the study, by either hiding or amplifying some of the relevant physical processes found in natural conditions. We discuss some observed cases of bias, including general practices that can lead to compromises associated with simplified assumptions. The analysis presented will identify potential pathways to move forward with laboratory and field measurements, which could better inform predictors to produce more robust, universal and accurate predictions on flow-vegetation-sediment interactions.

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“…Asimismo, se demuestra el efecto hidrodinámico de la vegetación a medida que se incrementa el flujo, aunque esta tendencia es muy variable según el tipo de especie y condiciones hidráulicas (Järvelä, 2002;Nikora et al, 2008). En este aspecto Fathi-Moghadam et al (2011), Fathi-Moghadam y Drikvandi (2012) y Green (2005b), entre otros, observaron que existe una relación no-lineal entre la resistencia al flujo de la vegetación y las características del flujo (velocidad, calado, ancho, etc. ), aplicable también a macrófitos (Dawson y Robinson, 1984).…”

Section: Caracterización Del Coeficiente De Rugosidadunclassified

Evaluación numérico-experimental del comportamiento histérico del coeficiente de rugosidad de los macrófitos

et al. 2018

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Sanz-Ramos et al. | Evaluación numérico-experimental del comportamiento histérico del coeficiente de rugosidad […] RESUMENLa problemática asociada al crecimiento masivo de macrófitos en el Bajo Ebro ha llevado a autoridades y gestores a examinar la posibilidad de paliar los efectos negativos que producen sobre el sistema hídrico, y los usos del agua, mediante la realización de avenidas controladas periódicas que provoquen su remoción. El presente trabajo tiene como objetivo principal evaluar el comportamiento hidráulico de los macrófitos mediante simulación numérica (modelo Iber) y su comparación con datos de campo, con el fin de explorar las mejores opciones posibles para diseñar avenidas controladas más eficaces. Para ello se han empleado diferentes relaciones entre el coeficiente de rugosidad y la altura de agua bajo tres enfoques distintos (constante, variable y variable con histéresis) a fin de calibrar el modelo numérico con los datos de campo. Se ha podido observar que el mejor ajuste se produce cuando dichas curvas son de tipo variable con histéresis (diferente rama de subida que de bajada).Palabras clave | macrófitos; coeficiente de rugosidad variable; avenidas controladas; simulación hidráulica. ABSTRACT

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Physical and Numerical Modeling of Submerged Vegetation Roughness in Rivers and Flood Plains

Cited by 29 publications

References 18 publications

Performance Assessment of Bench‐Terraces Through 2‐D Modelling

Performance Assessment of Bench‐Terraces Through 2‐D Modelling

Simplification bias: lessons from laboratory and field experiments on flow through aquatic vegetation

Evaluación numérico-experimental del comportamiento histérico del coeficiente de rugosidad de los macrófitos

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