Tarsier Tutorial: Adding GroundWater to Watershed Simulation

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  • 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

Adding aquifer Information to your Network Data

From the known terrain data, estimate some characteristics of the aquifer below your watershed. This will be critical for estimating interactions between the surface and groundwater.

  • Open your Marmoset form with all appropriate data (eg Net Data, Precipitation Series, Model Time, Landscape Parameters...)
  • For your convenience you can open and save your Watershed form in the Watershed Usee control within the marmoset form.
  • 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 0 for a homogeneous percolation rate. The higher this value, the less percolation will occur at steep reaches.
    • 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 corresponds to 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. This is theoretically the amount of ET that occurs at 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 (m/day) at which water will leave the shallow storage and enter the aquifer.

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....

Who has taken this tutorial?

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Disclaimer

This page may contain students' work completed as part of assigned coursework. It may not be accurate. It does not necessarily reflect the opinion or policy of CSUMB, its staff, or students.

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