Model:TopoFlow-Channels-Kinematic Wave: Difference between revisions
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|Spatial dimensions=2D | |Spatial dimensions=2D | ||
|Spatialscale=Landscape-Scale, Watershed-Scale | |Spatialscale=Landscape-Scale, Watershed-Scale | ||
|One-line model description=Kinematic Wave process component for a D8-based, spatial hydrologic model. | |One-line model description=Kinematic Wave process component for flow routing in a D8-based, spatial hydrologic model. | ||
|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. The kinematic wave method (Lighthill and Whitham, 1955) is the simplest method for modeling flow in open channels. This method combines mass conservation with the simplest possible treatment of momentum conservation, namely that all terms in the general momentum equation (pressure gradient, local acceleration and convective acceleration) are neglible except the friction and gravity terms. A flow in which gravitational acceleration is exactly balanced by friction is referred to as steady, uniform flow. For these flows the water surface slope, energy slope and bed slope are all equal. | |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. The kinematic wave method (Lighthill and Whitham, 1955) is the simplest method for modeling flow in open channels. This method combines mass conservation with the simplest possible treatment of momentum conservation, namely that all terms in the general momentum equation (pressure gradient, local acceleration and convective acceleration) are neglible except the friction and gravity terms. A flow in which gravitational acceleration is exactly balanced by friction is referred to as steady, uniform flow. For these flows the water surface slope, energy slope and bed slope are all equal. | ||
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V_w = d^2 * ( L * tan(θ) ) + d * (L * w) = wetted volume of a trapezoidal channel (m) | V_w = d^2 * ( 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=The basic stability condition is: dt < (dx / u_min), where dt is the | |Describe time scale and resolution constraints=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. | ||
|Describe any numerical limitations and issues=This model/component needs more rigorous testing. | |Describe any numerical limitations and issues=This model/component needs more rigorous testing. | ||
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Revision as of 22:45, 16 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-Kinematic Wave
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