Summary
Also known as
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Model type
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Single
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Model part of larger framework
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Note on status model
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Date note status model
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Technical specs
Supported platforms
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Unix, Linux, Mac OS, Windows
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Other platform
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Programming language
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Python
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Other program language
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None (but uses NumPy package)
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Code optimized
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Single Processor
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Multiple processors implemented
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Nr of distributed processors
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Nr of shared processors
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Start year development
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2001
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Does model development still take place?
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Yes
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If above answer is no, provide end year model development
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Code development status
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When did you indicate the 'code development status'?
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Model availability
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As code, As teaching tool
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Source code availability (Or provide future intension)
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Through CSDMS repository
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Source web address
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Source csdms web address
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Program license type
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Apache public license
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Program license type other
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Memory requirements
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Standard
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Typical run time
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Minutes to hours
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In/Output
Describe input parameters
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These inputs must be provided as grids:
- 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 = slope of the channel bed or hillslope (m / m)
- Manning_n = Manning roughness parameter (s / m^(1/3))
- bed_width = bed width for trapezoidal cross-section (m)
- bank_angle = bank angle for trapezoid (deg) (from vertical)
These inputs can be provided as scalars or grids:
- sinuosity = channel sinuosity (m/m) (along-channel / straight length)
- init_depth = initial water depth (m) (See HTML help)
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.
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:
Method code: 2
Method name: Diffusive_Wave
Manning flag: 1
Law of Wall flag: 0
Time step: Scalar 6.00000000 (sec)
D8 flow code: Grid Treynor_flow.rtg (none)
D8 slope: Grid Treynor_slope.rtg (m/m)
Manning N: Grid Treynor_chan-n.rtg (s/m^(1/3))
Bed width: Grid Treynor_chan-w.rtg (m)
Bank angle: Grid Treynor_chan-a.rtg (deg)
Init. depth: Scalar 0.00000000 (m)
Sinuosity: Scalar 1.00000000 (m/m)
ADD ADDITIONAL, OUTPUT OPTIONS HERE.
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Input format
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ASCII, Binary
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Other input format
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Describe output parameters
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[[Describe output parameters model::****** THERE SEEMS TO BE A BUG IN THE FORM HERE *******
This component computes the following variables, as grids:
- Q = discharge [m^3/s]
- u = flow velocity [m/s]
- d = flow depth [m]
- f = friction factor [none]
- Rh = hydraulic radius [m]
- S_free = free-surface slope [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.]]
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Output format
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ASCII, Binary
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Other output format
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Pre-processing software needed?
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Yes
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Describe pre-processing software
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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.
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Post-processing software needed?
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Yes
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Describe post-processing software
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None, except visualization software. Grid sequences saved in netCDF files can be viewed as animations and saved as movies using VisIt.
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Visualization software needed?
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Yes
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If above answer is yes
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Other visualization software
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VisIt
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Process
Describe processes represented by the model
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The diffusive wave method for flow routing in the channels of a D8-based river network.
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Describe key physical parameters and equations
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[[Describe key physical parameters::****** THERE SEEMS TO BE A BUG IN THE FORM HERE *******
Main equations used by this component:
ΔV(i,t)= Δt * [ R(i,t) Δx Δy - Q(i,t) + Σk Q(k,t) ] = change in water volume [m^3], mass conservation
d = {[ w^2 + 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)
Q = v * Aw = discharge of water [m^3 / s]
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
Rh = Aw / Pw = hydraulic radius [m]
Aw = d * [w + (d * tan(θ))] = wetted cross-sectional area of a trapezoid [m^2]
Pw = w + [2 * d / cos(θ)] = wetted perimeter of a trapezoid [m]
Vw = d^2 * [ L * tan(θ) ] + d * [L * w] = wetted volume of a trapezoidal channel [m]
(Source: TopoFlow HTML Help System)]]
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Describe length scale and resolution constraints
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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.
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Describe time scale and resolution constraints
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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.
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Describe any numerical limitations and issues
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This model/component needs more rigorous testing.
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Testing
Describe available calibration data sets
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This model/component is typically not calibrated to fit data, but is run with a best guess or measured value for each input parameter.
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Upload calibration data sets if available:
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Describe available test data sets
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Available test data sets:
- Treynor watershed, in the Nishnabotna River basin, Iowa, USA.
- (Two large rainfall events.)
- Small basin in Kentucky.
- Inclined plane for testing.
- Arctic watershed data from Larry Hinzman (UAF).
- See /data/progs/topoflow/3.0/data on CSDMS cluster.
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Upload test data sets if available:
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Describe ideal data for testing
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Several test datasets are stored on the CSDMS cluster at: /data/progs/topoflow/3.0/data.
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Other
Do you have current or future plans for collaborating with other researchers?
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Collaborators include: Larry Hinzman (UAF), Bob Bolton, Anna Liljedahl (UAF), Stefan Pohl, Tom Over and others
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Is there a manual available?
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Yes
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Upload manual if available:
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Model website if any
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This site.
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Model forum / discussion board
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Comments
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Please note:
- 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: http://csdms.colorado.edu/wiki/Model:TopoFlow.
- 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.
- 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.
- The Numerical Python module (numpy) is used for fast, array-based processing.
- This model has an OpenMI-style interface, similar to OpenMI 2.0. Part of this interface is inherited from "CSDMS_base.py".
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Introduction
History
Papers
Issues
Help
Input Files
Output Files
Download
Source |