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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 +
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18:31:52, 17 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. +
The input variables for the Energy Balance … The input variables for the Energy Balance method of estimating losses due to evaporation are defined as follows:</br> Q_SW = net shortwave radiation (W / m^2)</br> Q_LW = net longwave radiation (W / m^2)</br> T_air = air temperature (deg C)</br> T_surf = surface (snow) temperature (deg C)</br> T_soil_x = soil temperature at depth x (deg C)</br> x = reference depth in soil (m)</br> K_soil = thermal conductivity of soil (W / (m deg_C))</br> u_z = wind velocity at height z (m / s)</br> z = reference height for wind (m) (above land surface)</br> z_0 = surface roughness height (m) (with no snow)</br> h0_snow = initial snow depth (m)</br> ρ_air = density of the air (kg / m^3)</br> c_air = specific heat capacity of air (J / (kg deg_C))</br> L_v = latent heat of vaporization, water (J / kg) (2500000)</br> g = gravitational constant, Earth = 9.81 (m / s^2)</br> κ = von Karman's constant = 0.41 (unitless) </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: Energy_Balance</br> Time step: Scalar 3600.00000000 (sec)</br> alpha: Scalar 1.20000000 (none)</br> K_soil: Scalar 0.44999999 (W/m/deg_C)</br> soil_x: Scalar 0.05000000 (m)</br> T_soil_x: Scalar 0.00000000 (deg C)</br> Save grid timestep: Scalar 60.00000000 (sec)</br> Save er grids: 0 Case5_2D-ETrate.rts (m/s)</br> Save pixels timestep: Scalar 60.00000000 (sec)</br> Save er pixels: 0 Case5_0D-ETrate.txt (m/s) Case5_0D-ETrate.txt (m/s) +
Main equations used by this component:
ET … Main equations used by this component:</br> ET = (1000 * Q_et) / (ρ_water * L_v) = evaporation rate (mm / sec)</br> Q_et = (Q_SW + Q_LW + Q_c + Q_h) = energy flux used to evaporate water (W / m^2)</br> Q_c = K_soil * (T_soil_x - T_surf) * (100 / x)= conduction energy flux (W / m^2) (between surf. and subsurf.)</br> Q_h = ρ_air * c_air * D_h * (T_air - T_surf) = sensible heat flux (W / m^2)</br> D_n = u_z * κ^2 / LN((z - h_snow) / z0_air)^2 = bulk exchange coeff. (neutrally stable conditions) (m / s)</br> D_h = D_n / (1 + (10 * Ri)), (T_air > T_surf) = bulk exchange coeff. for heat (m / s) (stable) </br> = D_n * (1 - (10 * Ri)), (T_air < T_surf) = bulk exchange coeff. for heat (m / s) (unstable)</br> Ri = g * z * (T_air - T_surf) / (u_z^2 (T_air + 273.15)) = Richardson's number (unitless)air + 273.15)) = Richardson's number (unitless) +
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. +
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 Energy Balance method of estimating losses due to evaporation. +
Typical timesteps are on the order of seconds to minutes. Model can be run for a full year or longer, if necessary. +
Active +
This process component is part of a spatially-distributed hydrologic model called TopoFlow, but it can now be used as a stand-alone model. +
Scott +
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0.06 +
Standard +
Hydrology +
energy +, balance +, evaporation +, component +, model called topoflow +, spatially-distributed hydrologic model +, hydrologic model called +, called topoflow +, process component +, component is part +, spatially-distributed hydrologic +, hydrologic model +, model called +, stand-alone model +, topoflow +, model +, process +, part +, basins + and topoflow-evaporation-energy balance +
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>.
16:36:02, 6 June 2025 +
1 +
Evaporation process component (Energy Balance method) for 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 +
