Browse wiki
From CSDMS
About this component:
*This component was … About this component:</br>*This component was developed as part of the TopoFlow hydrologic model, which was originally written in IDL and had a point-and-click GUI. For more information on TopoFlow, please goto: https://csdms.colorado.edu/wiki/Model:TopoFlow.</br>*When used from within the CSDMS Modeling Tool (CMT), this component has "config" button which launches a graphical user interface (GUI) for changing input parameters. The GUI is a tabbed dialog with a Help button at the bottom that displays HTML help in a browser window.</br>*This component also has a configuration (CFG) file, with a name of the form: <case_prefix>_channels_diff_wave.cfg. This file can be edited with a text editor.</br>*The Numerical Python module (numpy) is used for fast, array-based processing.</br>*This model has an OpenMI-style interface, similar to OpenMI 2.0. Part of this interface is inherited from "CSDMS_base.py".his interface is inherited from "CSDMS_base.py". +
Yes +
No but planned +
Single Processor +
Creation date"Creation date" is a predefined property that corresponds to the date of the first revision of a subject and is provided by <a target="_blank" rel="nofollow noreferrer noopener" class="external text" href="https://www.semantic-mediawiki.org/wiki/Help:Special_properties">Semantic MediaWiki</a>.
01:44:56, 16 February 2010 +
Collaborators include: Larry Hinzman (UAF), Bob Bolton, Anna Liljedahl (UAF), Stefan Pohl, Tom Over and others +
This model/component is typically not calibrated to fit data, but is run with a best guess or measured value for each input parameter. +
Available test data sets:
*Treynor watersh … Available test data sets:</br>*Treynor watershed, in the Nishnabotna River basin, Iowa, USA.</br>* (Two large rainfall events.)</br>*Small basin in Kentucky.</br>*Inclined plane for testing.</br>*Arctic watershed data from Larry Hinzman (UAF).</br>*See /data/progs/topoflow/3.0/data on CSDMS cluster./progs/topoflow/3.0/data on CSDMS cluster. +
Several test datasets are stored on the CSDMS cluster at: /data/progs/topoflow/3.0/data. +
These inputs must be provided as grids:
*f … These inputs must be provided as grids:</br>*flow_codes = D8 flow codes (Jenson 1984 convention), (NE,E,SE,S,SW,W,NW,N) → (1,2,4,8,16,32,64,128)</br>*bed_slope = slope of the channel bed or hillslope (m / m)</br>*Manning_n = Manning roughness parameter (s / m^(1/3))</br>*bed_width = bed width for trapezoidal cross-section (m)</br>*bank_angle = bank angle for trapezoid (deg) (from vertical)</br></br>These inputs can be provided as scalars or grids:</br>*sinuosity = channel sinuosity (m/m) (along-channel / straight length)</br>*init_depth = initial water depth (m) (See HTML help)</br></br>Grids must be saved in binary files with no header. All variables should be stored as 4-byte, floating-point numbers (IEEE standard) except flow codes, which are unsigned, 1-byte integers.</br></br>The behavior of this component is controlled with a configuration (CFG) file, which may point to other files that contain input data. Here is a sample configuration (CFG) file for this component:</br> Method code: 2</br> Method name: Diffusive_Wave</br> Manning flag: 1</br> Law of Wall flag: 0</br> Time step: Scalar 6.00000000 (sec)</br> D8 flow code: Grid Treynor_flow.rtg (none)</br> D8 slope: Grid Treynor_slope.rtg (m/m)</br> Manning N: Grid Treynor_chan-n.rtg (s/m^(1/3))</br> Bed width: Grid Treynor_chan-w.rtg (m)</br> Bank angle: Grid Treynor_chan-a.rtg (deg)</br> Init. depth: Scalar 0.00000000 (m)</br> Sinuosity: Scalar 1.00000000 (m/m)</br> Save grid timestep: Scalar 60.00000000 (sec)</br> Save Q grids: 1 Case5_2D-Q.rts (m^3/s)</br> Save u grids: 0 Case5_2D-u.rts (m/s)</br> Save d grids: 0 Case5_2D-d.rts (m)</br> Save f grids: 0 Case5_2D-f.rts (none)</br> Save pixels timestep: Scalar 60.00000000 (sec)</br> Save Q pixels: 1 Case5_0D-Q.txt (m^3/s)</br> Save u pixels: 0 Case5_0D-u.txt (m/s)</br> Save d pixels: 0 Case5_0D-d.txt (m)</br> Save f pixels: 0 Case5_0D-f.txt (none) Case5_0D-f.txt (none)
Main equations used by this component:
ΔV … Main equations used by this component:</br> ΔV(i,t)= Δt * ( R(i,t) Δx Δy - Q(i,t) + Σk Q(k,t) ) = change in water volume (m^3), mass conservation</br> d = {( w^2 + 4 tan(θ) V / L)^1/2 - w } / (2 tan(θ)) = mean water depth in channel segment (m) (if θ > 0)</br> d = V / (w * L) = mean water depth in channel segment (m) (if θ = 0)</br> Q = v * Aw = discharge of water (m^3 / s)</br> v = n^(-1) * Rh^(2/3) * S^(1/2) = section-averaged velocity (m / s), Manning's formula</br> v = ( g * Rh * S)^(1/2) * LN( a * d / z0) / κ = section-averaged velocity (m / s), Law of the Wall</br> Rh = Aw / Pw = hydraulic radius (m)</br> Aw = d * (w + (d * tan(θ))) = wetted cross-sectional area of a trapezoid (m^2)</br> Pw = w + (2 * d / cos(θ)) = wetted perimeter of a trapezoid (m)</br> Vw = d^2 * ( L * tan(θ) ) + d * (L * w) = wetted volume of a trapezoidal channel (m)</br></br>(Source: TopoFlow HTML Help System)nnel (m)
(Source: TopoFlow HTML Help System) +
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. +
This model/component needs more rigorous testing. +
This component computes the following vari … This component computes the following variables, as grids:</br> Q = discharge (m^3/s)</br> u = flow velocity (m/s)</br> d = flow depth (m)</br> f = friction factor (none)</br> Rh = hydraulic radius (m)</br> S_free = free-surface slope (m/m)</br>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. rate must no smaller than the process timestep. +
None, except visualization software. Grid sequences saved in netCDF files can be viewed as animations and saved as movies using VisIt. +
Another program must be used to create the input grids. This includes a D8 flow grid derived from a DEM for the region to be modeled. The earlier, IDL version of TopoFlow can be used to create some of these. +
The diffusive wave method for flow routing in the channels of a D8-based river network. +
The basic stability condition is: dt < … The basic stability condition is: dt < (dx / u_min), where dt is the timestep, 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. run for a full year or longer, if necessary. +
Active +
This process component is part of a spatia … 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.the wall, the water-surface slope is used. +
Scott +
Has query"Has query" is a predefined property that represents meta information (in form of a <a target="_blank" rel="nofollow noreferrer noopener" class="external text" href="https://www.semantic-mediawiki.org/wiki/Subobject">subobject</a>) about individual queries and is provided by <a target="_blank" rel="nofollow noreferrer noopener" class="external text" href="https://www.semantic-mediawiki.org/wiki/Help:Special_properties">Semantic MediaWiki</a>.
Last editor is"Last editor is" is a predefined property that contains the page name of the user who created the last revision and is provided by <a target="_blank" rel="nofollow noreferrer noopener" class="external text" href="https://www.semantic-mediawiki.org/wiki/Help:Special_properties">Semantic MediaWiki</a>.
0.06 +
Standard +
Hydrology +
wave +, diffusive +, spatial +, model +, model called topoflow +, spatially-distributed hydrologic model +, hydrologic model called +, called topoflow +, hydrologic model +, model called +, stand-alone model +, process component +, component is part +, spatially-distributed hydrologic +, compute flow velocities +, diffusive wave +, river network +, topoflow +, basins + and topoflow-channels-diffusive wave +
basins +
Single +
This site. +
Modification date"Modification date" is a predefined property that corresponds to the date of the last modification of a subject and is provided by <a target="_blank" rel="nofollow noreferrer noopener" class="external text" href="https://www.semantic-mediawiki.org/wiki/Help:Special_properties">Semantic MediaWiki</a>.
16:35:28, 6 June 2025 +
1 +
Diffusive Wave process component for flow routing in a D8-based, spatial hydrologic model +
1560 30th street +
80305 +
true +
None (but uses NumPy package) +
Apache public license +
Python +
Minutes to hours +
Through web repository +
https://github.com/peckhams/topoflow +
2001 +
Model developer +
