HEC-HMS version 4.8 was used to update the project files provided here - Rainfall_Workshop.zip.

Overview

In this tutorial, you will compute two simulation runs and compare results from the two meteorologic models. Both simulation runs use the same basin model and control specifications. The first simulation run uses the Gage Weights precipitation method and the second simulation run uses the Inverse Distance precipitation method. Components of both simulation runs are shown below.

Simulation Run name: Specified Wt

  • Basin Model: Punxsutawney
  • Meteorologic Model: Specified Gage Wt
  • Control Specifications: 1 May 1996


Simulation Run Name: Inverse Dist

  • Basin Model: Punxsutawney
  • Meteorologic Model: Inverse Distance Wt
  • Control Specifications: 1 May 1996
  1. Open HEC-HMS and select the File menu. Choose the Open… menu option and select the Rainfall Workshop item in the list of existing projects.
  2. Click on the Open button and the Rainfall Workshop will be loaded.
  3. Compute the Inverse Dist simulation run
  4. Compute the Specified Wt simulation run
  5. Click on the Results tab and expand the results for the Punxsutawney subbasin as shown below.
    Results tab.
  6. Click on the subbasin (Punxsutawney) Graph from the Specified Wt simulation run and move the plot to the side.
  7. Click on the subbasin (Punxsutawney) Graph from the Inverse Dist simulation run and move the plot to the side and under the first plot.
  8. The graphs of both simulation runs are shown simultaneously below.
    Graph of both simulation runs.
  9. Click on the Summary Table of the Specified Wt simulation run and move the table to the side.
  10. Click on the Summary Table of the Inverse Dist simulation run and move the table to the side and under the first table.
  11. The summary tables of both simulation runs are shown simultaneously below.
    Summary table of both simulation runs.
  12. Click on the Precipitation result for the Puxsutwaney subbasin in the Specified Wt simulation run.
  13. Press Control + Click on the Precipitation result for the Punxsutawney subbasin in the Inverse Dist simulation run.
  14. Basin average precipitation hyetographs from the Specified Wt (solid line) and Inverse Dist (dashed line) simulation runs are shown simultaneously below. The differences in the computed basin average precipitation is due to the different methods for computing basin average precipitation. The gage weights approach uses user defined gage weights, and the inverse distance method automatically computes the gage weights using the distance from the gage to a user defined node (subbasin centroid). The example shows a way to compare time-series results from two separate simulation runs. Additional time-series can be added to the plot by clicking on the time-series result in the Watershed Explorer and dragging/dropping the time-series onto the plot's x or y axis. 
    Precipitation from both simulation runs.