Model:TopoFlow-Channels-Diffusive Wave: Difference between revisions
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(To be used as a template for all TopoFlow process components.) |
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|Spatial dimensions=2D | |Spatial dimensions=2D | ||
|Spatialscale=Landscape-Scale, Watershed-Scale | |Spatialscale=Landscape-Scale, Watershed-Scale | ||
|One-line model description= | |One-line model description=Diffusive Wave process component for a D8-based, spatial hydrologic model | ||
|Extended model description= | |Extended model description=This process component is part of a spatially-distributed hydrologic model called TopoFlow, but it can now be used as a stand-alone model. It uses the "diffusive wave" method to compute flow velocities for all of the channels in a D8-based river network. This method includes a pressure gradient term that is induced by a water-depth gradient in the downstream direction. This means that instead of using bed slope in Manning's equation or the law of the wall, the water-surface slope is used. | ||
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{{Model technical information | {{Model technical information | ||
|Supported platforms=Unix, Linux, Mac OS, Windows | |Supported platforms=Unix, Linux, Mac OS, Windows | ||
|Programming language=Python | |Programming language=Python (and uses the NumPy package) | ||
|Other program language= | |Other program language=None | ||
|Code optimized=Single Processor | |Code optimized=Single Processor | ||
|Start year development=2001 | |Start year development=2001 | ||
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|Source code availability=Through CSDMS repository | |Source code availability=Through CSDMS repository | ||
|Program license type=Apache public license | |Program license type=Apache public license | ||
|OpenMI compliant= | |OpenMI compliant=Yes (partially) | ||
|CCA component=Yes | |CCA component=Yes | ||
|IRF interface= | |IRF interface=Yes | ||
|Memory requirements=Standard | |Memory requirements=Standard | ||
|Typical run time=Minutes to hours | |Typical run time=Minutes to hours | ||
}} | }} | ||
{{Input - Output description | {{Input - Output description | ||
|Describe input parameters= | |Describe input parameters= | ||
These inputs must be provided as grids (in binary files): | |||
*flow_codes | *flow_codes = D8 flow codes (Jenson 1984 convention) [NE,E,SE,S,SW,W,NW,N] → [1,2,4,8,16,32,64,128] | ||
*bed_slope | *bed_slope = slope of the channel bed or hillslope [m / m] | ||
*Manning_n | *Manning_n = Manning roughness parameter [s / m^(1/3)] | ||
*bed_width | *bed_width = bed width for trapezoidal cross-section [m] | ||
*bank_angle | *bank_angle = bank angle for trapezoid [deg] (from vertical) | ||
These inputs can be provided as scalars or grids: | |||
*sinuosity = channel sinuosity [unitless] (along-channel / straight length) | |||
*init_depth = initial water depth [m] (See HTML help) | |||
Here is a sample configuration (CFG) file for this component: | |||
*Method code: 2 | *Method code: 2 | ||
*Method name: Diffusive_Wave | *Method name: Diffusive_Wave | ||
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*D8 flow code: Grid Treynor_flow.rtg [none] | *D8 flow code: Grid Treynor_flow.rtg [none] | ||
*D8 slope: Grid Treynor_slope.rtg [m/m] | *D8 slope: Grid Treynor_slope.rtg [m/m] | ||
*Manning N: Grid Treynor_chan-n.rtg | *Manning N: Grid Treynor_chan-n.rtg [s/m^(1/3)] | ||
*Bed width: Grid Treynor_chan-w.rtg [m] | *Bed width: Grid Treynor_chan-w.rtg [m] | ||
*Bank angle: Grid Treynor_chan-a.rtg [deg] | *Bank angle: Grid Treynor_chan-a.rtg [deg] | ||
*Init. depth: Scalar 0.00000000 [m] | *Init. depth: Scalar 0.00000000 [m] | ||
*Sinuosity: Scalar 1.00000000 [m/m] | *Sinuosity: Scalar 1.00000000 [m/m] | ||
|Input format=ASCII, Binary | |Input format=ASCII (for Scalar and Time Series), Binary (for Grid and Grid Sequence) | ||
|Describe output parameters= | |Describe output parameters= | ||
This component computes the following variables, as grids: | |||
discharge, Q, [m^3/s]; | |||
flow velocity, u, [m/s]; | |||
flow depth, d, [m]; | |||
friction factor, f, [none]; | |||
free-surface slope, S_free, [m/m]. | |||
The user can choose which, if any, of these to save. Each may be saved as a grid sequence, indexed by time, in a netCDF file, at a specified sampling rate. Each may also be saved for a set of "monitored" grid cells, each specified as a (row,column) pair in a file with the name "<case_prefix>_outlets.txt". With this option, computed values are saved in a multi-column text file at a specified sampling rate. Each column in this file corresponds to a time series of values for a particular grid cell. For both options the sampling rate must no smaller than the process timestep. | |||
|Output format=ASCII, Binary | |Output format=ASCII, Binary | ||
|Pre-processing software needed?=Yes | |Pre-processing software needed?=Yes | ||
|Describe pre-processing software= | |Describe pre-processing software=Another program must be used to create a D8 flow grid from a DEM for the region to be modeled. | ||
|Post-processing software needed?=Yes | |Post-processing software needed?=Yes | ||
|Describe post-processing software= | |Describe post-processing software=None, except visualization software. | ||
|Visualization software needed?= | |Visualization software needed?=Grid sequences saved in netCDF files can be viewed as animations and saved as movies using VisIt. | ||
}} | }} | ||
{{Process description model | {{Process description model | ||
|Describe processes represented by the model= | |Describe processes represented by the model=The diffusive wave method for flow routing in the channels of a D8-based river network. | ||
|Describe key physical parameters and equations= ( | |Describe key physical parameters and equations= (Source: TopoFlow HTML Help System) | ||
------------------------------------------------------------ | ------------------------------------------------------------ | ||
ΔV(i,t)= Δt * [ R(i,t) Δx Δy - Q(i,t) + Σk Q(k,t) ] = change in water volume [m3], mass conservation | ΔV(i,t)= Δt * [ R(i,t) Δx Δy - Q(i,t) + Σk Q(k,t) ] = change in water volume [m3], mass conservation | ||
d = {[ w2 + 4 tan(θ) V / L]1/2 - w } / [2 tan(θ)] = mean water depth in channel segment [m] (if θ > 0) | d = {[ w2 + 4 tan(θ) V / L]^1/2 - w } / [2 tan(θ)] = mean water depth in channel segment [m] (if θ > 0) | ||
d = V / [w * L] = mean water depth in channel segment [m] (if θ = 0) | d = V / [w * L] = mean water depth in channel segment [m] (if θ = 0) | ||
Q = v * Aw = discharge of water [m3 / s] | Q = v * Aw = discharge of water [m3 / s] | ||
v = n-1 * | v = n-1 * Rh^2/3 * S^1/2 = section-averaged velocity [m / s], Manning's formula | ||
v = ( g * Rh * S)1/2 * LN( a * d / z0) / κ = section-averaged velocity [m / s], Law of the Wall | v = ( g * Rh * S)1/2 * LN( a * d / z0) / κ = section-averaged velocity [m / s], Law of the Wall | ||
Rh = Aw / Pw = hydraulic radius [m] | Rh = Aw / Pw = hydraulic radius [m] | ||
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Vw = d2 * [ L * tan(θ) ] + d * [L * w] = wetted volume of a trapezoidal channel [m] | Vw = d2 * [ L * tan(θ) ] + d * [L * w] = wetted volume of a trapezoidal channel [m] | ||
|Describe length scale and resolution constraints=Recommended grid cell size is around 100 meters, but can be parameterized to run with a wide range of grid cell sizes. DEM grid dimensions are typically less than 1000 columns by 1000 rows. | |Describe length scale and resolution constraints=Recommended grid cell size is around 100 meters, but can be parameterized to run with a wide range of grid cell sizes. DEM grid dimensions are typically less than 1000 columns by 1000 rows. | ||
|Describe time scale and resolution constraints= | |Describe time scale and resolution constraints=The basic stability condition is: dt < (dx / u_min), where dt is the timestp, dx is the grid cell size and u_min is the smallest velocity in the grid. This ensures that flow cannot cross a grid cell in less than one time step. Typical timesteps are on the order of seconds to minutes. Model can be run for a full year or longer, if necessary. | ||
|Describe any numerical limitations and issues= | |Describe any numerical limitations and issues=This model/component needs more rigorous testing. | ||
}} | }} | ||
{{Model testing | {{Model testing | ||
|Describe available calibration data sets= | |Describe available calibration data sets=This model/component is typically not calibrated to fit data, but is run with a best guess or measured value for each input parameter. | ||
|Describe available test data sets=Available test | |Describe available test data sets=Available test data sets: | ||
* Treynor watershed, in the Nishnabotna river basin, in Iowa, USA. Two large events. | * Treynor watershed, in the Nishnabotna river basin, in Iowa, USA. Two large rainfall events. | ||
* Small basin in Kentucky. | |||
* Inclined plane for testing. | |||
* Arctic watershed data from Larry Hinzman (UAF). | * Arctic watershed data from Larry Hinzman (UAF). | ||
|Describe ideal data for testing=Several test datasets | |Describe ideal data for testing=Several test datasets are stored on the CSDMS cluster at: /data/progs/topoflow/3.0/data. | ||
}} | }} | ||
{{Users groups model | {{Users groups model | ||
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{{Documentation model | {{Documentation model | ||
|Provide key papers on model if any=Peckham, S.D. (2008) Geomorphometry and spatial hydrologic modeling (Chapter 22), In: Hengl, T. and Reuter, H.I. (Eds), Geomorphometry: Concepts, Software and Applications. Developments in Soil Science, vol. 33, Elsevier, 377-393 pp. | |Provide key papers on model if any=Peckham, S.D. (2008) Geomorphometry and spatial hydrologic modeling (Chapter 22), In: Hengl, T. and Reuter, H.I. (Eds), Geomorphometry: Concepts, Software and Applications. Developments in Soil Science, vol. 33, Elsevier, 377-393 pp. | ||
|Manual model available=Yes | |Manual model available=Yes, as HTML help pages. | ||
|Model website if any=This site. | |Model website if any=This site. | ||
}} | }} | ||
{{Additional comments model | {{Additional comments model | ||
|Comments=The Numerical Python module (numpy) is used for fast, array-based processing | |Comments=This component was developed as part of the TopoFlow hydrologic model and is used in CSDMS demonstration projects. For more information, please see the model page for TopoFlow. The Numerical Python module (numpy) is used for fast, array-based processing. | ||
}} | }} | ||
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Revision as of 23:51, 15 February 2010
Contact
Name | Scott Peckham |
Type of contact | Model developer |
Institute / Organization | CSDMS, INSTAAR, University of Colorado |
Postal address 1 | 1560 30th street |
Postal address 2 | |
Town / City | Boulder |
Postal code | 80305 |
State | Colorado |
Country | USA"USA" is not in the list (Afghanistan, Albania, Algeria, Andorra, Angola, Antigua and Barbuda, Argentina, Armenia, Australia, Austria, ...) of allowed values for the "Country" property. |
Email address | Scott.Peckham@colorado.edu |
Phone | 303-492-6752 |
Fax |
TopoFlow-Channels-Diffusive Wave
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