Revision as of 17:19, 9 April 2010

• This tutorial provides instructions on how to add a groundwater interaction component to you Watershed Simulation Model.

Prerequisites

Tarsier Tutorial: Watershed simulation using the Marmoset Model

• Watershed analysis saved with all data
• Working watershed simulation model in Marmoset

Adding aquifer Information to your Network Data

• Open your Marmoset form with all appropriate data (eg Net Data, Precipitation Series, Model Time, Landscape Parameters...)
• For your convenience you can save your Watershed form in the Watershed Usee control
• Open and save your watershed analysis form with these data: Hydro DEM, Net Ptr, Stream raster and Tarsier Network Data (tne)
• Open Aquifer Tab in Watershed Analysis tool
• Click Calc Floodplain
  • Warning: Must have your Net Ptr, HydroDEM, and Stream Raster open in their usee controls.
  • This tool creates a raster covering your floodplain according to your set max flood height
  • Default max flood height it 1 meter. This should be estimated and changed to suit your watershed.
• Click Calc Floodplain Area
  • Warning: Must have your Net Ptr, HydroDEM, and Stream Raster And your floodplain raster open in their usee controls.
  • This too breaks up your floodplain and connects a floodplain area with a corresponding node.
• Click Calc Aquifer From Floodplain
  • Warning, must have your floodplain raster open, and have calculated floodplain area
  • This tool uses a hillslope parameter to estimate triangular aquifer geometry
  • The default hillslope is 15 degrees from horizontal, make a good estimation for your watershed.
  • Warning, a hillslope less then or equal to zero, or greater or equal to ninety will not work properly.

Including GroundWater processes in you Watershed Model

• Go to "Watershed models" tab
• In the "Watershed model type" group, there is an option to use the groundwater model, when you are ready, check that box to include ground water
• There are a number of ground water parameters grouped at the bottom of the page
  • The Percolation parameter is the percentage of surface water that will infiltrate into the shallow subsurface storage
  • The Slope Factor gives the steeper channels of the river a smaller tendency to percolate water. Set this to 1 for a homogeneous percolation rate.
  • Darcy's K is a coefficient of subsurface lateral flow. A value of zero will result in no lateral subsurface flow. The higher the value the faster water will flow.
  • Near Surface Storage Depth is the space available for percolation from the surface water in a given time step.
  • Aquifer Porosity is the space available for water in the aquifer. (eg A value of 0.5 means that of the entire aquifer, 50% is occupied by material and the rest is available for water)
  • Max ET is the maximum amount of subsurface evapotranspiration that will occur. Right now this value of ET is set for the Surface.
  • ET Extinction Depth is how far down evapotranspiration will take place under the surface. The ET in between the surface and the extinction depth banishes linearly with depth.
  • The Aq Perc Rate is the rate at which water will leave the shallow storage and enter the aquifer, this is confusingly percent per time step. Also, 0.5 = %50 etc...

Rough parameters

1. Percolation Parameter = 0.6
2. Slope Factor = 1
3. Darcy k = 2
4. Near Surface Storage Depth = 10
5. Aquifer Porosity = 0.35
6. Max ET = 0.02
7. Max flood height = 1
8. hillslope parameter = 20

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• In Progress....

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