By Nick Van and Matt Fleming, P.E.

Over the past decade, one of the most requested new features sent to the Hydrologic Engineering Center's Hydrologic Modeling System (HEC-HMS) team was to create summary reports documenting model input information and simulation results. The HEC-HMS team found a funding partner in the Maricopa County Flood Control District and was able to release new report options in HEC-HMS Versions 4.6 and 4.7. Minor improvements to the new reports have been made since the original release. Two types of reports can be generated, both options can be found under the Tools | Reports menu option as shown in Figure 1.

Figure 1, Location to generate Standard and Statistics Reports.

The Standard Report summarizes information in the basin model and provides results for the selected simulation. As shown in Figure 2, you must select a compute first. The program will load the results information and basin model information for the selected compute. Then you can control how much information is saved to the Standard Report by turning on or off different summary tables and results plots. After selecting the information to save in a report, you must enter a name and location for the report to be saved. The program will create an HTML file with the summary information when you click the Generate Report button.  

Figure 2, Available options for configuring a Standard Report.

Figure 3 (a - c) provide example results in a Standard Report. The HTML file can be viewed by dragging and dropping the file onto a web browser. As shown, you can see when the model was last computed, the software version used to compute the simulation, global parameter summary tables, and global results tables. You can also view parameters and results for individual elements in the basin model. Here is an example standard report file - 2004CalibratedModel.html. 

Figure 3 (a), The Standard Report summarizes all elements in the basin model. Figure 3 (b), The Standard Report summarizes results for all elements in the basin model.

Figure 3 (c), The Standard Report summarizes all method parameters in the basin model.

The Statistics Report summarizes model performance metrics for all locations with observed flow in the basin model (e.g., Figure 4 (a, b)). Model performance metrics included in the report are: Coefficient of Determination (R2), Nash Sutcliffe Efficiency, Root Mean Squared Error - observations standard deviation ratio (RMSE Stdev), and Percent Bias. The example basin model, Figure 4 (a, b), shows locations with observed flow in a basin model and then a Statistics Report with performance metrics for a simulation run. Here is an example statistics report file - 2004StatisticsReport.html.

Figure 4 (a), Basin model elements highlighted in red are Computation Points with observed flow.Figure 4 (b), The Statistics Report summarized model performance for all elements containing observed flow.

The new reporting option allows modelers to generate reports that can accompany models when a review needs to be performed. The reports are a quick way for the reviewer to see how the model was parameterized and how the model performed during calibration and validation without having to open the model and search for information. In addition, the reports serve as a way to archive the model, including parameterization and performance.