Guide for selecting Manning's roughness coefficients for natural channels and flood plains

Arcement, George J.; Schneider, Verne R.

doi:10.3133/wsp2339

Cited by 262 publications

(87 citation statements)

References 5 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…aerial view in the horizontal plane), suggesting the spatial distribution and its degree of fragmentation may be more important to boundary layer dynamics than the topography itself. Our results here would support that assertion, indicating a need to better understand the role of spatial arrangement and role of 'gaps' (sensu Yager et al 1993, Duarte 2001, Granata et al 2001) in influencing nearbed hydrodynamics (which can modify bed roughness; Arcement and Schneider 1989) and its role in the generation of turbulence.…”

Section: Discussionsupporting

confidence: 80%

Spatial arrangement of biogenic reefs alters boundary layer characteristics to increase risk of microplastic bioaccumulation

Lim

Fraser

Knights

2020

Environ. Res. Lett.

View full text Add to dashboard Cite

Microplastics are now synonymous with human impacts on the environment and as a threat to marine organisms. Numerous taxa are at risk from microplastics including commercially valuable bivalves as seafood, which are also disproportionately important as biogenic reef-forming species that enhance biodiversity such that they are commonly protected under conservation actions. As a sessile filter-feeding organism, bivalves are highly susceptible to microplastic ingestion but despite their socio-economic and ecological importance, no research has been undertaken to assess how a reef 's structural arrangement might affect plastic ingestion. Here, using a series of flume experiments, we examined how change in spatial arrangement of the blue mussel, Mytilus edulis, interacts with different flow speeds to effect retention of microplastic over reef surfaces and ingestion risk by individual mussels. Our results show that clumped spatial arrangements reduce boundary layer velocities, and increase turbulence, boundary layer thickness and plastic retention over reef surfaces under faster flow conditions, increasing plastic ingestion by 3-fold. Our findings suggest that the structural arrangement and rugosity of natural reef structures may create natural sinks of anthropogenic pollution, and species like Mytilus that are also important species for human consumption, while disproportionately susceptible to microplastic pollution, may be useful bioindicators of microplastic pollution.

show abstract

Section: Discussionsupporting

confidence: 80%

Spatial arrangement of biogenic reefs alters boundary layer characteristics to increase risk of microplastic bioaccumulation

Lim

Fraser

Knights

2020

Environ. Res. Lett.

View full text Add to dashboard Cite

show abstract

“…15]. During the simulation stage, Manning's n-values were introduced according to Brunner [15] and Arcement, Schneider [9]. Since the flow condition at study river reach was nearly steady uniform, the downstream boundary condition was set at normal.…”

Section: Hydraulic Modellingmentioning

confidence: 99%

“…Model-based floodplain studies provide water surface profiles and floodplain maps for landuse planning and flood-prone areas [6][7][8]. It is import to mention that floodplain studies are complex cases where roughness coefficient should be set in part rather than one representative value for the entire river reach [9].…”

Section: Introductionmentioning

confidence: 99%

“…HEC-RAS, a worldwide applied hydraulic model, developed by U.S. Army Corps of Engineers, it computes water surface profile and several hydraulic parameters for both steady and unsteady, 1D/2D dimensional, gradually varied flow in both natural and human-made channels [15]. Also, HEC-RAS allows for sediment transport/mobile bed computations and water temperature modelling as well [9,15].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Calibration of channel roughness in intermittent rivers using HEC-RAS model: case of Sarimsakli creek, Turkey

Ardıçlıoğlu¹,

Kuriqi

2019

SN Appl. Sci.

View full text Add to dashboard Cite

Natural channel's roughness determination constitutes one the most challenging procedure towards the development of hydraulic models for flood prediction and flood hazard mapping. Therefore, it is essential to calibrate and validate the channel's Manning's n roughness coefficient using simulation models. In this study, we calibrated and validated Manning's n roughness coefficient using HEC-RAS for Sarimsakli creek that is tributary of the Kizilirmak river in central Anatolia, Turkey. For calibration of Manning's n-values, six different flow regimes were considered based on mean daily flow records between 2005 and 2010. We found that calculated water surface profiles for different Manning's n are slightly lower than the measured one, that indicates a continuous underestimation of the roughness coefficient n by the model. Therefore, our results suggest that higher values of Manning's n should be considered in case of the intermittent rivers. A polynomial relationship was proposed between roughness values and Froude numbers. Finally, a linear relation was established between calculated and measured Manning's n roughness coefficient. Nevertheless, results showed that careful attention should be given to higher n-values because the differences between HEC-RAS and Manning's n becomes larger. Solution-oriented results obtained and the methodology applied to the Sarimsakli creek may serve as a practical reference for HEC-RAS modelling and flood prediction in intermittent rivers. Keywords Ecohydraulics • Flood risk • Flooding • Hydraulic model • Riparian vegetation • River restoration List of symbols HEC-RAS River Analysis System (RAS) developed by Hydrologic Engineering Center (HEC) of U.S. Army Corps of Engineers 1D/2D One dimensional/two dimensional n Manning's roughness coefficient (s/m 1/3) Q Flow discharge (m 3 s −1) V Flow velocity (m s −1) A Submerged cross-section's area (m 2) R Hydraulic radius (m) P Wetted perimeter (m) S ws Water surface slope (m/m) Fr Froude number (−) g Gravitational acceleration (ms −2) S Friction slope (m/m) ε Average difference (%) h meas Measured depth (m) h calc Calculated depth (m) S o Channel bottom slope (m/m) S f Friction slope (m/m) t Time (s) q l Lateral inflow (m 3 s −1) x Longitudinal coordinate (m)

show abstract

“…Then, a parameterization of rating curve was defined based on steady and uniform flow in the main channel simulation by River Analysis System developed by HEC -Hydrologic Engineering Center (BRUNNER, 2010). At each gauging station, a range of roughness coefficient was simulated, varying from 0.011 to 0.060 (ARCEMENT; SCHNEIDER, 1989;CHOW, 1959;WEBBER et al, 2018) and obtained a standard equation, it was adapted from Manning-Strickler equation:…”

Section: Reducing the Dimensionality Of Rating Curvementioning

confidence: 99%

Joint calibration of a hydrological model and rating curve parameters for simulation of flash flood in urban areas

Lima

Fernandes

Nascimento

2019

RBRH

View full text Add to dashboard Cite

Calibration process is usually time demanding and as much streamflow information as possible in rainfall-runoff models. Nevertheless, from a practical point of view, the available information is measurement of water level, which is essential to design rating curves. This manuscript proposes a set of joint calibration of hydrological model parameters with a range of rating curves, developed for the main channel of the catchment in a crowded urban area. As an alternative of free calibration, the simulations were carried out based on a list of proficient parameters. Four streamflow gauging stations were analysed and used to subdivide the basin. The hourly lumped rainfall-runoff model GR4H was applied to four critical flash flood events to create a rank of Nash-Sutcliffe efficiency criteria (NSE) applying the best set of parameters. The results indicated that the hydrological model errors were compensated by hydraulics errors and they presented an equifinality in the process. RESUMONos modelos chuva-vazão, a etapa de calibração geralmente exige tempo e grande quantidade de informação das vazões. No entanto, do ponto de vista prático, a informação usualmente disponível é o nível d'água medido, este, por sua vez, utilizado na construção das curvas-chave. Este artigo propõe uma calibração conjunta dos parâmetros de um modelo hidrológico com uma gama de curvas-chave, as quais foram desenvolvidas para o canal principal da bacia em estudo em uma área altamente ocupada e urbanizada. Como alternativa a uma calibração livre, as simulações foram realizadas com base em uma lista de parâmetros previamente testados. Quatro estações linimétricas foram analisadas e utilizadas para subdividir a área da bacia. O modelo concentrado horário de chuva-vazão GR4H foi utilizado com quatro eventos críticos de inundações bruscas com o intuito de criar uma classificação de critérios de eficiência de Nash-Sutcliffe aplicando o melhor conjunto de parâmetros. Os resultados indicam que os erros do modelo hidrológico foram compensados pelos erros hidráulicos e apresentaram uma equifinalidade no processo. Palavras-chave:Modelo chuva-vazão; Inundações bruscas; Curvas-chave; Hidrologia urbana; Modelagem hidrológica e ambiental. RBRH, Porto Alegre, v. 24, e24, 2019 Joint calibration of a hydrological model and rating curve parameters for simulation of flash flood in urban areas 2/15

show abstract

Guide for selecting Manning's roughness coefficients for natural channels and flood plains

Cited by 262 publications

References 5 publications

Spatial arrangement of biogenic reefs alters boundary layer characteristics to increase risk of microplastic bioaccumulation

Spatial arrangement of biogenic reefs alters boundary layer characteristics to increase risk of microplastic bioaccumulation

Calibration of channel roughness in intermittent rivers using HEC-RAS model: case of Sarimsakli creek, Turkey

Joint calibration of a hydrological model and rating curve parameters for simulation of flash flood in urban areas

Contact Info

Product

Resources

About