This tutorial and the downloadable project files in the final results were completed using HEC-HMS 4.10 beta 6.

Overview

This tutorial will guide you through the process of using the Maricopa Clark, S-Graph, and Green-Ampt tools which became available in HEC-HMS version 4.9. Each of these tools can be accessed by clicking Tools | Data | Maricopa. The Maricopa tools were designed specifically to accompany a standard work flow followed by Maricopa County water professionals. 

Data

The Maricopa tools will require several geo-spatial files and tabular CSV files as inputs. These include existing subbasin, longest flow path, soils, and land use shapefiles, as well as several landuse and soils tables in CSV format.

Download the necessary data files here -  maricopa_data.zip

Creating a Geo-referenced Basin Model

  1. Open HEC-HMS version 4.9 or later.
  2. Create a new project by clicking File | New.
  3. Specify the name, description, and location of the project as seen below. Select U.S. Customary as the default unit system.
  4. Next, copy the GIS "maricopa_data.zip" folder to the "data" folder in the HEC-HMS project directory and unzip the files. 
  5. Now we need to create a basin model. Navigate to the Basin Model Manager by selecting Components | Basin Model Manager.
  6. Select New... and enter Maricopa_Clark as the name of the basin. Select Create.
  7. Now we need to import existing geo-referenced subbasins.  Select the Maricopa_Clark basin model in the watershed explorer tree. Then select GIS | Import Georeferenced Elements.
  8. In the first step of the wizard, select Subbasins. Click Next.
  9. In the second step of the wizard, select the existing subbasins shapefile from the "data" folder. Click Next.
  10. In the third step of the wizard, select AREAID as the field definition that represents the subbasin name. Click Finish.
  11. A popup will appear that prompts the user to specify a basin model coordinate system. Click Skip to use the projected coordinate system of the subbasin shapefile.
  12. Now that we have a geo-referenced basin model, we need to change the transform method to Clark Unit Hydrograph. Click Parameters | Transform | Change Method...

  13. Click Yes to confirm that you wish to change methods. Select Clark Unit Hydrograph in the Method: dropdown box. Click Change.
  14. In the watershed explorer tree, select a subbasin, click the Transform tab in the component editor, and select Maricopa County AZ USA in the Method: dropdown box. Repeat for each subbasin. Save the project.
  15. The Maricopa Clark computation requires longest flowpath characteristics. At this point, you can perform the steps necessary to compute subbasin characteristics in HEC-HMS (create/link a terrain model, perform steps on the GIS menu in HEC-HMS). Or you can go straight to the Maricopa Clark Wizard and provide a longest flowpath shapefile that contains an attribute field matching the subbasin names as well as attribute fields for upstream and downstream elevations in units of feet. For this tutorial, we will go straight to the Maricopa Clark Wizard.

Applying the Maricopa Clark Tool

  1. Navigate to the Maricopa Clark Tool by clicking Tools | Data | Maricopa | Clark...

  2. The first step of the Maricopa Clark Wizard requires a basin model to be selected. Select the appropriate basin model and click Next.

  3. The second step of the Maricopa Clark Wizard requires the user to select the land use shapefile, land use lookup table, and Kb lookup table. Furthermore, field names must be specified for two separate join operations to take place. The user must select the field names for the land use lookup table and land use shapefile join, and the user must also select the field names for the land use lookup table and Kb lookup table join. Lastly, the user needs to define the 'm' and 'b' lookup field names within the Kb table. Select the necessary inputs and click Next.
  4. The third step of the Maricopa Clark Wizard allows for the user to use HEC-HMS subbasin characteristics in the Maricopa Clark calculations, or a longest flowpath shapefile can be specified instead.
     
  5. For this example, we want to use an external shapefile for the Maricopa Clark calculations.  Unselect the checkbox, and then select the longest flowpath shapefile from the "data" folder and populate the appropriate fields for the subbasin id, upstream elevation, and downstream elevation. Note: using the longest flowpath shapefile option will override previously computed subbasin characteristics values, if they exist. Click Next to begin the computation.
  6. Once the calculations are complete, the Clark Unit Hydrograph transform global editor will automatically be populated with Flowpath Length (MI), Adjusted Flowpath Slope (FT/MI) and Resistance Coefficient parameters. The user may choose to edit any of the calculated parameters in the global editor, or accept them as they are. Select Apply to save the parameters. This will save the values to the global editor and also populate the component editors for each of the subbasins. Save the project.
  7. Additionally, HEC-HMS will output intermediate calculations as notes in the message console.

Applying the Maricopa S-Graph Tool

  1. Let's create another basin model that utilizes the S-Graph transform method.
  2. Right-click the Maricopa_Clark basin model in the watershed explorer tree and select Create Copy...

  3. Enter Maricopa_SGraph as the name and select Copy.
  4. Select the basin Maricopa_SGraph in the watershed explorer tree and click ParametersTransform Change Method...
  5. Click Yes to confirm that you wish to change methods. Select User-Specified S-Graph in the Method: dropdown box. Click Change. Save the project.
  6. In the watershed explorer tree, select a subbasin, click the Transform tab in the component editor, and select Regression in the Method: dropdown box. Repeat for each subbasin. Save the project.
  7. Navigate to the Maricopa S-Graph Tool by clicking Tools | Data | Maricopa | S-Graph...

  8. The first step of the Maricopa S-Graph Wizard requires a basin model to be selected. Select the Maricopa_SGraph basin model and click Next.

  9. The second step of the wizard requires a landuse shapefile and lookup table to be selected. Additionally, the landuse join fields must be defined as well as the landuse 'Kn' field name found in the landuse lookup table. Select the necessary inputs and click Next.
  10. For this example, we want to use external shapefiles for the Maricopa S-Graph calculations. On the third and final step of the wizard, unselect the checkbox, and then select the longest flowpath and centroidal flowpath shapefiles from the "data" folder and populate the appropriate fields for the subbasin id, upstream elevation, and downstream elevation. Note: specifying external shapefiles will override previously computed subbasin characteristics values, if they exist. Click Next to begin the computation.
  11. Once the calculations are complete, the User-Specified S-Graph transform global editor will automatically be populated with Flowpath Length (MI), Flowpath Slope (FT/MI), Centroid Length (MI), Roughness, M, and P parameters. The user may choose to edit any of the calculated parameters in the global editor, or accept them as they are. Select Apply to save the parameters. This will save the values to the global editor and also populate the component editors for each of the subbasins. Save the project.
  12. Additionally, HEC-HMS will output intermediate calculations as notes in the message console.

Applying the Maricopa Green-Ampt Tool

  1. Let's use the Maricopa Green-Ampt Tool to calculate and populate loss and canopy parameters for the Maricopa_SGraph basin model.
  2. Select the basin Maricopa_SGraph in the watershed explorer tree and click ParametersLoss Change Method...
  3. Click Yes to confirm that you wish to change methods. Select Green and Ampt in the Method: dropdown box. Click Change
  4. Click ParametersCanopy Change Method...
  5. Click Yes to confirm that you wish to change methods. Select Simple Canopy in the Method: dropdown box. Click Change. Save the project.
  6. Navigate to the Maricopa Green-Ampt Tool by clicking Tools | Data | Maricopa | Green-Ampt...
  7. The first step of the Maricopa Green-Ampt Wizard requires a basin model to be selected. Select the Maricopa_SGraph basin model and click Next.

  8. The second step of the wizard requires a landuse shapefile, landuse lookup table, soils shapefile, soils lookup table, and bare ground hydraulic conductivity (XKSAT) lookup table to be selected. Select the necessary inputs and click Next.
  9. The third step of the wizard involves defining the fields that will be used to join the landuse shapefile and landuse lookup table, as well as the soils shapefile and the soils lookup table. Specify the join fields and click Next.
  10. The fourth and final step of the wizard involves matching various input parameters to their field names in the three lookup tables (landuse, soils, and hydraulic conductivity). Match the parameters to their field names in the lookup tables as seen below. If the header names in each of the three input tables follows the normal Maricopa convention, the dropdown menus should default to the correct selections. Click Next.
  11. Once the calculations are complete, the Green and Ampt loss global editor will automatically be populated with Initial Type, Initial Deficit, Suction, Conductivity, and Percent Impervious parameters. The user may choose to edit any of the calculated parameters in the global editor, or accept them as they are. Select Apply to save the loss parameters.
  12. Select Close to exit the Green and Ampt global editor. The Simple Canopy global editor should now be visible with calculated estimates for Max Storage. The user may choose to edit any of the calculated parameters in the global editor, or accept them as they are. Select Apply to save the canopy parameters.
  13. Select Close to exit the Simple Canopy global editor. Save the project.
  14. Additionally, HEC-HMS will output intermediate calculations as notes in the message console.

Download the final project files here - final_Maricopa.zip