Model help:AgDegNormalFault: Difference between revisions

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==Main equations==
==Main equations==
* Manning-Strickler formulation
::::{|
|width=500px|<math>C_{f}=\alpha _{r}\left ( \frac{H}{K_{c}} \right )^{\frac{1}{6}}</math>
|width=50px align="right"|(1)
|}
* Total bed material load per unit width
::::{|
|width=500px|<math>\frac{q_{t}}{{\sqrt{RgD}D}}=\alpha_{t}\left ( \frac{\varphi_{s}\tau _{b}}{\rho RgD} -\tau_{c}^* \right )^{n_{t}}</math>
|width=50px align=right|(2)
|}


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<div class="NavFrame collapsed" style="text-align:left">
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!Symbol!!Description!!Unit
!Symbol!!Description!!Unit
|-
|-
| X
| Q
| Streamwise coordinate
| flood discharge
| m <sup>3</sup> / s
|-
| x
| streamwise coordinate
| m
| m
|-
|-
| ΔX
| η
| Spatial step length
| river bed elevation
| m
| m
|-
|-
| t
| t
| Temporal coordinate
| time step
| seconds
| year
|-
|-
| C<sub>f</sub>  
| B
| Non-dimensional friction coefficient
| river width
| m
|-
| D
| grain size of the bed sediment
| mm
|-
| λ<sub>p</sub>
| bed porosity
| -
| -
|-
|-
| Q<sub>w</sub>
| R
| Flood discharge
| submerged specific gravity
| m<sup>3</sup>/s
|-
| I<sub>f</sub>
| Flood intermittency
| -
| -
|-
|-
| B<sub>c</sub>
| ξ<sub>d</sub>
| Channel width
| downstream water surface elevation
| m
| m
|-
|-
| D
| q<sub>w</sub>
| Characteristic grain size
| water discharge per unit width
| mm
| m<sup>2</sup> / s
|-
| λ<sub>p</sub>
| Bed porosity
| -
|-
|-
| k<sub>c</sub>
| k<sub>c</sub>
| Composite roughness height
| composite roughness height
| mm
| m
|-
| G
| imposed annual sediment transfer rate from upstream
| tons / annum
|-
|-
| S<sub>I</sub>
| G<sub>tf</sub>
| Ambient bed slope
| upstream sediment feed rate
| -
| -
|-
|-
| G<sub>tf</sub>
| ξ<sub>d</sub>
| Imposed annual sediment transport rate
| downstream water surface elevation
| tons/annum
| m
|-
|-
| L
| L
| Length of reach
| length of reach under consideration
| m
| m
|-
|-
| Δt
| q<sub>w</sub>
| Time step
| water discharge per unit width
| year
| m<sup>2</sup> / s
|-
|-
| N<sub>toprint</sub>
| i
| number of time steps to printout
| number of time steps per printout
| -
| -
|-
|-
| N<sub>print</sub>
| p
| number of printouts
| number of printouts desired
| -
| -
|-
|-
| M
| M
| Number of spatial intervals
| number of spatial intervals
| -
|-
| R
| submerged specific gravity of sediment
| -
| -
|-
|-
| a<sub>u</sub>
| S<sub>f</sub>
| Upwinding coefficient (1 = full upwind, 0.5 = central difference)
| friction slope
| -
| -
|-
|-
| α<sub>r</sub>
| F<sub>r</sub>
| Coefficient in Manning-Strickler
| Froude number
| -
| -
|-
|-
| α<sub>s</sub>
| U
| Coefficient in sediment transport relation
| flow velocity
| m / s
|-
| C<sub>f</sub>
| bed friction coefficient
| -
| -
|-
|-
| η<sub>t</sub>
| g
| Exponent in sediment transport relation
| acceleration of gravity
| m/ s^2
|-
| α<sub>r</sub>
| coefficient in Manning-Stricker, dimensionless coefficient between 8 and 9
| -
| -
|-
|-
| τ<sup>*</sup><sub>c</sub>
| k<sub>s</sub>
| Reference Shields number in sediment transport relation
| grain roughness
| m
|- 
| n<sub>k</sub>
| dimensionless coefficient typically between 2 and 5
| -
|- 
| τ<sup>*</sup>
| Shield number
| -
| -
|-
|-
| φ<sub>s</sub>
| ρ
| Fraction of bed shear stress due to skin friction
| fluid density
| kg / m<sup>3</sup>
|-
| ρ<sub>s</sub>
| sediment density
| kg / m<sup>3</sup>
|-
| τ<sub>c</sub>
| critical Shields number for the onset of sediment motion
| -
| -
|-
|-
| R
| ψ<sub>s</sub>
| Submerged specific gravity
| the fraction of bed shear stress
| -
| -
|-
|-
| Cz
| q<sub>t</sub> <sup>*</sup>
| Non-dimensional Chézy friction coefficient
| Einstein number
| -
| -
|-
|-
| G<sub>tf</sub>
| q<sub>t</sub>
| imposed annual sediment transport rate
| volume sediment transport rate per unit width
| -
| -
|-
|-
| r<sub>f</sub>
| I<sub>f</sub>
| the fraction of reach length such that all points downstream of x = r<sub>f</sub>L undergo downward faulting
| flood intermittency
| -
| -
|-
|-
| t<sub>f</sub>
| t<sub>f</sub>
| the time from beginning of calculation at which faulting occurs
| the time from beginning of calculation at which faulting occurs
| s
|-
| G<sub>t</sub>
| the annual sediment yield
| tone/yr
|-
| t<sub>a</sub>
| the number of seconds in a year
| -
| -
|-
|-
| ∆η
| Q<sub>f</sub>
| height of faulting
| sediment transport rate during flood discharge
|-
| α<sub>t</sub>
| dimensionless coefficient in the sediment transport equation, equals to 8
| -
|-
| n<sub>t</sub>
| exponent in sediment transport relation, equals to 1.5
| -
|-
| τ<sub>c</sub> <sup>*</sup>
| reference Shields number in sediment transport relation, equals to 0.047
|-
| C<sub>f</sub>
| bed friction coefficient, equals to τ<sub>b</sub> / (ρ U<sup>2</sup> )
| -
|-
| C<sub>Z</sub>
| dimensionless Chezy resistance coefficient.
|-
| S<sub>l</sub>
| initial bed slope of the river
| -
|-
| η<sub>i</sub>
| initial bed elevation
| -
|-
| x
| downstream coordinate
| m
|-
| τ
| shear stress on bed surface
| N / m<sup>2</sup>
|-
| q<sub>b</sub>
| bed material load
| tons / year
|-
| Δx
| spatial step length, equals to L / M
| m
|-
| Q<sub>w</sub>
| flood discharge
| m<sup>3</sup> / s
|-
| Δt
| time step
| year
|-
| Ntoprint
| number of time steps to printout
| -
|-
| Nprint
| number of printouts
| -
|-
| a<sub>U</sub>
| upwinding coefficient (1=full upwind, 0.5=central difference)
| -
|-
| α<sub>s</sub>
| coefficient in sediment transport relation
| -
|-
| r<sub>f</sub>
| the fraction of reach length such that all point downstream of x = r<sub>f</sub>L undergo downward faulting
| -
|-
| Δη
| the height of faulting
| m
| m
|-
|-
|}
|}


'''Output'''
'''Output'''
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|-
|-
| η
| η
| Bed surface elevation
| bed surface elevatioon
| m
| m
|-
|-
| S
| H
| Bed slope
| water depth
| -
| m
|-
|-
| H
| ξ
| Water depth
| water surface elevation
| m
| m
|-
|-
| τ<sub>b</sub>
| τ<sub>b</sub>
| Total (skin friction + form drag) Shields number
| bed shear stress
| kg / (s^2 m)
|-
| S
| bed slope
| -
| -
|-
|-
| q<sub>t</sub>
| q<sub>t</sub>
| total bed material load
| total bed material load
| m<sup>2</sup>/s
| m<sup>2</sup> / s
|-
|-
|}
|}
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</div>
</div>
==Notes==
==Notes==
If the channel slope is negative and the water depth is not a number, “nan”, check the time step and the spatial step length.  In particular, the time step may be too large or equivalently the spatial step length may be too small.  Change these values and run the model again
If the channel slope is negative and the water depth is not a number, “nan”, check the time step and the spatial step length.  In particular, the time step may be too large or equivalently the spatial step length may be too small.  Change these values and run the model again.
 
The water depth is calculated using a Chézy formulation, when only the Chézy coefficient is specified in the input text file.  The Manning-Strickler formulation is implemented, when only the roughness height, k<sub>c</sub>, and the coefficient α<sub>r</sub> are given in the input file.  When all the three parameters are present, the program will ask the user which formulation they would like to use.


==Examples==
==Examples==
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==References==
==References==
<span class="remove_this_tag">Key papers</span>
* Paola, C., Heller, P. L. & Angevine, C. L.  1992  The large-scale dynamics of grain-size variation in alluvial basins.  I: Theory.  Basin Research, 4, 73-90.
 
* Meyer-Peter, E., and Müller, R.  1948  Formulas for bed-load transport. Proceedings, 2nd Congress International Association for Hydraulic Research, Rotterdam, the Netherlands, 39-64.


==Links==
==Links==
<span class="remove_this_tag">Any link, eg. to the model questionnaire, etc.</span>
* [[http://csdms.colorado.edu/wiki/Model:AgDegNormalFault Model:AgDegNormalFault]]
* [[http://csdms.colorado.edu/wiki/Model_help:AgDegNormal Model_help:AgDegNormal]]


[[Category:Modules]] [[Category:Utility components]]
[[Category:Utility components]]

Revision as of 14:28, 10 May 2011

The CSDMS Help System

AgDegNormalFault

This is used to calculate aggradation and degradation of a river reach using the normal flow approximation; with an extension for calculation of the response to a sudden fault along the reach.

Model introduction

This program computes 1D bed variation in rivers due to differential sediment transport in which it is possible to allow the bed to undergo a sudden vertical fault of a specified amount, at a specified place and time. Faulting is realized by moving all notes downstream of the specified point downward by the amount of the faulting.

The sediment is assumed to be uniform with size D. All sediment transport is assumed to occur in a specified fraction of time during which the river is in flood, specified by an intermittency. A Manning-Strickler formulation is used for bed resistance. A generic relation of the general form of that due to Meyer-Peter and Muller is used for sediment transport. The flow is computed using the normal flow approximation.

Model parameters

Parameter Description Unit
Input directory path to input files
Site prefix Site prefix for Input/Output files
Case prefix Case prefix for Input/Output files
Parameter Description Unit
Flood discharge m3 / s
Intermittency -
Channel Width m
Grain size mm
Bed Porosity -
Roughness height mm
Ambient Bed Slope
Imposed Annual Sediment Transfer Rate from Upstream tons / annum
Length of reach m
Time step year
Number of Time Steps per Printout
Number of printout
intervals
Upwinding coefficient (1 = full upwind, 0.5 = central difference)
Coefficient in Manning-Strickler Resistance Relation
Coefficient in Sediment Transport Relation
Exponent in Sediment Transport Relation
Critical Shield stress
Fraction of bed shear stress that is skin friction
Submerged specific gravity of sediment
Height of faulting m
Fraction of reach length such that all points downstream undergo downward faulting -
Time from beginning of calculation at which faulting occurs yrs
Parameter Description Unit
Model name name of the model -
Author name name of the model author -

Uses ports

This will be something that the CSDMS facility will add

Provides ports

This will be something that the CSDMS facility will add

Main equations

Notes

If the channel slope is negative and the water depth is not a number, “nan”, check the time step and the spatial step length. In particular, the time step may be too large or equivalently the spatial step length may be too small. Change these values and run the model again.

Examples

An example run with input parameters, BLD files, as well as a figure / movie of the output

Follow the next steps to include images / movies of simulations:

See also: Help:Images or Help:Movies

Developer(s)

Name of the module developer(s)

References

  • Paola, C., Heller, P. L. & Angevine, C. L. 1992 The large-scale dynamics of grain-size variation in alluvial basins. I: Theory. Basin Research, 4, 73-90.
  • Meyer-Peter, E., and Müller, R. 1948 Formulas for bed-load transport. Proceedings, 2nd Congress International Association for Hydraulic Research, Rotterdam, the Netherlands, 39-64.

Links

Retrieved from "https://csdms.colorado.edu/csdms_wiki/index.php?title=Model_help:AgDegNormalFault&oldid=22057"