WMS:Maricopa County Modeling

Tips and Locations for Downloading Hydrologic Data

GSDA Site

HEC-1 Modeling with Green and Ampt

1. Read the DEM into WMS (download DEMs from the USGS Seamless site).
2. Convert coordinates of the DEM when reading:
   1. Convert from: Horizontal system of Geographic NAD 83 and vertical system of NAVD 88, Meters.
   2. Convert to: State Plane NAD 83, Arizona Central Zone, horizontal and vertical units of US Survey feet, NAVD 88.
3. Read into WMS any image data to be used.
4. Run Topaz (Drainage module)
5. Set the flow accumulation threshold (Display Options | select DEM Data option)
6. Create the outlet(s) (Drainage module tools)
7. Use the delineate basins wizard
8. Read the Land Use shapefile. Download land use shapefiles from here. The file ending in "giras.exe" will be the file needed. The soils shapefile will be in the file ending in "core31.exe". A HUC number is needed for the watershed, whichcan be gotten by searching for the watershed on this site.
9. If needed, convert the coordinates of the land use data to State plane coordinates as described for DEMs above.
10. Create a new Land Use coverage and make sure it's set as the active coverage.
11. Go to the GIS module, drag a box around the watershed, and select the Mapping | Shapes→Feature Objects command.
12. Make sure the land use ID is mapped to the correct field in the land use coverage. Also map the land use name if needed.
13. Read the soils shapefile. The soil shapefile for Maricopa County can be downloaded with a bunch of other data in the FCDMC.zip file here. The "statsgo" (statewide, less accurate than "ssurgo" data) soil shapefile for any watershed in the US can be downloaded with the file ending in "core31.exe" from this location. "Ssurgo" data can be downloaded from the soil data mart here.
14. If needed, convert the coordinates of the soil data to State plane coordinates as described for DEMs above.
15. Create a new Soil Type coverage and make sure it's set as the active coverage.
16. Go to the GIS module, drag a box around the watershed, and select the Mapping | Shapes→Feature Objects command.
17. Make sure the soil type ID is mapped to the correct field in the soil type coverage. Also map the soil type name if needed.
18. Define the necessary Green and Ampt parameters for each land use type in the land use coverage. Do this by viewing the attributes of the land use type polygons in the land use coverage and viewing the Green and Ampt parameters. Several sample tables exist that give these Green and Ampt parameters for different land use types. One table is called "landusemagtable.tbl" in the FCDMC.zip file downloaded here.
19. Define the necessary Green and Ampt parameters for each soil type in the soil type coverage. Do this by viewing the attributes of the soil type polygons in the soil type coverage and viewing the Green and Ampt parameters. Several sample tables exist that give these Green and Ampt parameters for different soil types. One table is called "soilwmsgreenapmt.tbl" in the FCDMC.zip file downloaded here.
20. Go to the Hydrologic modeling module and select Calculators | Compute GIS Attributes from the menu. Change the computation type to Green-Ampt Parameters and select OK to compute the Green-Ampt parameters.
21. Make sure the current model is set to HEC-1 in the drop-down box at the top of the WMS window.
22. Select the HEC-1 | Job Control menu option.
23. Select Initialize Maricopa County Precipitation Data.
24. Select a rainfall grid (from the FCDMC.zip file that was downloaded) such as "noaa100y24h", which means 100-Year, 24-Hour precipitation.
25. Select the Compute Precipitation button and select OK. Select OK to close the HEC-1 Job Control Dialog.
26. Double-click on the basin and view the basin data and loss method data to make sure they are setup correctly. Select the Unit Hydrograph Method button in the Edit HEC-1 Parameters dialog.
27. Select the Clark method. Then select Compute Tc and R – Maricopa County. Enter the appropriate parameters and select OK to compute the Tc and R values.
28. Define routing if desired.
29. Run HEC-1.

Tutorials

Download Maricopa County Tutorials at http://wmsdocs.aquaveo.com/

Additional Information

More information about the Maricopa County interface development is located at http://emrl.byu.edu/FCDMC/