Once the inundation configuration is created, the hydraulic characteristics of an event must be defined. HEC-FIA accepts hydraulic data from HEC-DSS time-series and/or gridded files computed by a hydraulics model (e.g., HEC-HMS, HEC-RAS, HEC-ResSim, etc.). Note: Defining hydraulic events in HEC-FIA allows the user to map or set the path to the file but this step does not copy the file. Therefore, it is recommended to store HEC-DSS and/or gridded hydraulic data in the shared directory within the HEC-FIA study directory to ensure that the file(s) are stored with the project and shared between individuals.

Define HEC-DSS Time Series Events

When events are created using HEC-DSS files, HEC-FIA uses the watershed configuration that was associated with the inundation configuration to determine where the user has pre-defined output to be required. In a watershed configuration, the user has selected one or more of the following: a reservoir set, a cross section set, a storage area set, or a CCP set (standard or CCPs with holdout distribution areas).

During the import of those watershed elements, the user was required to define the mapping for A, B, and/or C parts for each element that was imported (review Watershed). HEC-FIA utilizes the A, B and C parts defined by the user at each location to compute a hydraulic event.

The user must select a HEC-DSS file path, and a computational output (E part) for inundation configurations (i.e., CCP Only, Cross Sections Only, and Grids and Cross Sections) which require mapping to *.dss time series files. Further, the HEC-DSS file path must coordinate with the A, B, and C parts imported in the CCP, cross section, or storage area set used in the selected watershed configuration (step 2 of the New Inundation Configuration wizard, review Creating New Inundation Configurations). To define HEC-DSS time series events:

  1. From the Study Tree, which is in the Study Pane, from the Inundation Data folder, right-click on the appropriate inundation configuration name. From the shortcut menu, click Define Event; a dialog box opens (based on the inundation configuration type).

  2. For the CCPs Only, Cross Sections Only and Grids and Cross Sections inundation configurations, the Define Event dialog box opens. From the Define Event dialog box, from the DSS File box, click the button. The Open browser window opens for HEC-DSS files .

    Figure: Inundation Data - Configuration Shortcut Commands


    Figure: Define Event Dialog Box - HEC-DSS Time Series


    Figure: Open Browser Window - Select HEC-DSS File

  3. Navigate to an existing HEC-DSS dataset (*.dss) for the hydraulic event of interest, select the HEC-DSS filename (e.g., LeveeSimulation.dss) and click Open. The Open browser window closes, and the path to the selected HEC-DSS file populates in the Define Event dialog box, in the DSS File box. In general, it is recommended to store HEC-DSS (and/or gridded) inundation data files in the shared HEC-FIA study directory.
  4. Select the correct HEC-DSS time step for the hydraulic data, from the E-Part list (which expresses the output time step of the regular time series records; available types are MIN, 15 MIN, 30 MIN or 1 HOUR).
  5. Click OK, the Define Event dialog box closes and the defined event(s) display in the Study Tree below the selected inundation configuration. If the incorrect HEC-DSS record was linked then the user can repeat the above steps to set the path to the correct HEC-DSS file.

For Cross Sections Only and for Grids And Cross Sections inundation configurations the linked HEC-DSS time series data can be checked for missing data. To check if all of the connections are set up correctly for the HEC-DSS file path specified:

  1. From the Study Tree, from the Inundation Data folder, from the inundation configuration name folder, right-click on the event (the F part) of interest (e.g., NB_FAILED); from the shortcut menu click Check for missing data. The Missing DSS Data dialog box opens.

    Figure: DSS Time Series Files - Check for missing data


    Figure: Missing DSS Data Dialog Box - Example

  2. If an invalid path is found, the cross section, or CCP is highlighted in red. If this occurs, the user should look at the A, B, and C parts imported with the cross section or CCP set, and verify that pathname parts exist in the HEC-DSS path submitted for these events. If the pathname parts do not exist, it is possible that the pathname parts were not in the final HEC-RAS or HEC-ResSim model that produced the HEC-DSS output, or a naming convention issue in the shapefile that defined the pathname parts exists.

Define Gridded Hydraulic Events

Grids can be used to define hydraulic characteristics throughout a study area. The five hydraulic characteristics that can be represented by grids are maximum depth, maximum instantaneous depth-times-velocity, arrival time for life loss calculations, arrival time for agricultural calculations, and flood duration for agricultural calculations. Structures will be assigned hydraulic characteristics based on the value of the grid cell for each grid in which the structure point is contained.

Hydraulic gridded datasets can be imported into HEC-FIA in many formats, including GeoTiff (.tif), ASCII grid (asc), floating point binary (.flt), Segmented Multi-Resolution Multi-Parameter (.smrmp), and virtual (.vrt) format. The GeoTiff (.tif) format is recommended for a more efficient operation of HEC-FIA once the file has been imported.

For the Grids Only inundation configuration only the following steps are required; however, for Grids and Cross Sections the user must first complete the steps in Define HEC-DSS Time Series Events, prior to completing the steps described below.

For Grids Only:

  1. From the Study Tree, which is in the Study Pane, from the Inundation Data folder, right-click on the appropriate inundation configuration name (e.g., Grids_Only). From the shortcut menu, click Define Event; the Grids Only Event dialog box opens.
  2. From the Grids Only Event dialog box enter a name for the event in the Name box and provide a description in the Description box.
  3. Depending on which grid types were selected for the Grids Only inundation configuration, a path to a grid for each grid type required. Be sure that all event grids come from the same HEC-RAS plan, or hydraulic model output. From an empty grid type box (e.g., Inundation Grid), click the button. The Open browser window opens for selecting gridded files.

  4. Navigate to an existing gridded dataset (.tif, .asc, .flt, .smrmp, or .vrt) for the hydraulic event of interest, select the filename and click Open. The Open browser window closes, and the path to the selected gridded file populates in the Grids Only Event dialog box. In general, it is recommended to store gridded (and/or HEC-DSS) inundation data files in the shared HEC-FIA study directory.

    Figure: Grids Only Event Dialog Box - Example


    Figure: Open Browser Window - Select Gridded File

  5. Click OK, the Grids Only Event dialog box closes and the defined event displays in the Study Tree below the selected Grids Only inundation configuration.

For Grids and Cross Sections:

  1. Once the defined HEC-DSS time series event(s) is completed (review Define HEC-DSS Time Series Events), from the Study Tree, from the Inundation Data folder, from the grids and cross sections inundation folder (e.g., Grids_and_XS), right-click on the appropriate event name (e.g., NB_NOTFAILED). From the event's shortcut menu, click Edit; and the Grids and Cross Sections Event dialog box opens.

  2. From the Grids and Cross Sections Event dialog box enter a name for the event in the Name box and provide a description in the Description box.

    Figure: Grids and Cross Sections - Edit Event Shortcut Command


    Figure: Grids and Cross Sections Event - Example

  3. Depending on which grid types were selected for the Grids and Cross Sections inundation configuration a path to a grid for each grid type is required. Be sure that all event grids come from the same HEC-RAS plan, or hydraulic model output. From an enabled empty grid type box (e.g., Inundation Grid), click thebutton.
  4. The Open browser window opens for selecting gridded files. Navigate to an existing gridded dataset (.tif, .asc, .flt, .smrmp, or .vrt) for the hydraulic event of interest, select the filename and click *Open. The Open browser window closes, and the path to the selected gridded file populates in the Grids and Cross Sections Event dialog box. In general, it is recommended to store gridded (and/or HEC-DSS) inundation data files in the shared HEC-FIA study directory.
  5. Click OK, the Grids and Cross Sections Event dialog box closes.
  6. Repeat Steps 1 through 5 until all HEC-DSS time series created events have the correct file paths to the gridded data specified from the Grids and Cross Sections Event dialog box.

Define Holdout Events

Holdout Cross Sections, Holdout Grids, and Holdout - RAS HDF inundation configurations are used for setting up a watershed for computing Flood Damages Reduced. The Flood Damages Reduced compute requires the evaluation of stage throughout the entire study area for each event. To accommodate this evaluation requirement, the HEC-RAS software is required to provide regulated and unregulated stages for HEC-FIA. Therefore, the Holdout Cross Section and Holdout Grids inundation configurations are designed to ingest HEC-RAS output in the form of HEC-DSS time series files, or Geotiff gridded inundation files (*.tif or *.vrt). The Event for an inundation configuration is where this data is defined. 

Similarly the Holdout - RAS HDF inundation configuration is designed to take hydraulic inputs from HEC-RAS, but instead of HEC-DSS files or Geotiffs, it requires native HEC-RAS results (*p##.hdf). The Holdout - RAS HDF Inundation configuration accepts inputs from 4 hydraulic events: regulated, unregulated, regulated without levee, and unregulated without levee.

Additionally, if the Holdout Cross Sections or Holdout Grids inundation configuration is intended to include reservoirs, then there is an option to use HEC-ResSim calculated holdout HEC-DSS time series for a project with reservoirs. NOTE: To use this option the user must have associated a watershed configuration which contains a reservoir set and a holdout CCPs set (review Import Common Computation Points); otherwise, the option to use and set the path to the HEC-ResSim holdout HEC-DSS time series is inaccessible. HEC-FIA provides an additional option to enter holdout distributions in an override table (from the New Alternative dialog box as discussed in Alternatives when including reservoirs for a flood damages reduced project when HEC-ResSim *.dss data is not available.

To Define Holdout Cross Sections Events:

  1. From the Study Tree, from the Inundation Data folder, right-click on the appropriate inundation configuration name. From the shortcut menu, click Define Event; and the Holdout Cross Sections Event dialog box opens.
  2. From the Holdout Cross Sections Event dialog box enter a name for the event in the Event Name box. Below the Event Name box there are two panels. From the top panel the user must select a HEC-DSS file path, and a computational output (E and F parts) for mapping the configuration to *.dss time series output from HEC-RAS. From the bottom panel the user has the option link holdout HEC-DSS time series output from HEC-ResSim.
  3. From the top panel of the Holdout Cross Sections Event dialog box, from the HEC-RAS Output box, click the button. The Open browser window opens for HEC-DSS files. Navigate to an existing HEC-RAS output HEC-DSS dataset (.dss) for the hydraulic event of interest, select the HEC-DSS filename (e.g., NorthBranch.dss) and click Open. The Open browser window closes, and the path to the selected HEC-DSS file populates in the Holdout Cross Sections Event dialog box, in the HEC-RAS Output box.

  4. Next, use the dropdown lists to complete the mapping to the linked .dss file by selecting the correct *E Part, Regulated and Unregulated HEC-DSS identifier. From the E Part list select the correct .dss time step for the regular time series hydraulic data (available output types are MIN, 15 MIN, 30 MIN or 1 HOUR). From the Regulated, and Unregulated lists select the appropriate F part identifiers.

    Figure: Holdout Event Dialog Box - Example

  5. If the user desires to link holdout .dss time series output from HEC-ResSim, then from the bottom panel of the Holdout Event dialog box, check the Use HEC-ResSim Calculated Holdout Time Series checkbox (disabled, by default). If this option is not desired, then skip to Step 7.
  6. Selecting the checkbox enables the user to select a HEC-DSS file path and the computational output (E and F parts) for the HEC-ResSim holdout time series. From the HEC-ResSim Output box, click thebutton, and the Open browser window for HEC-DSS files opens. From the Open browser window, navigate to an existing .dss dataset for the HEC-ResSim calculated holdout time series, select the HEC-DSS filename (e.g., simulation.dss) and click Open. The Open browser window closes, and the path to the selected .dss file populates in the *Holdout Event dialog box, in the HEC-ResSim Output box.
  7. Next, use the dropdown lists to complete the mapping to the linked .dss file by selecting the correct E Part and Output F Part HEC-DSS identifiers. From the E Part list, select the correct .dss time step for the hydraulic data. From the Output F Part list select the appropriate HEC-ResSim F part identifier.
  8. Click OK, the Holdout Cross Sections Event dialog box closes.

To Define Holdout Grids Events:

  1. From the Study Tree, from the Inundation Data folder, right-click on the appropriate inundation configuration name. From the shortcut menu , click Define Event; and the Holdout Grids Event dialog box opens.
  2. From the Holdout Grids Event dialog box enter a name for the event in the Event Name box . Below the Event Name box there are two panels. From the top panel the user must select the location of the HEC-RAS maximum depth grids for both the regulated and unregulated conditions.  From the bottom panel the user has the option link holdout HEC-DSS time series output from HEC-ResSim.
  3. From the top panel of the Holdout Grids Event dialog box, from the Regulated Grid box, click the  button. The Open browser window opens. Navigate to an existing HEC-RAS maximum depth grid for a regulated run for the hydraulic event of interest, select the grid filename (e.g., Depth (Max).vrt) and click Open. The Open browser window closes, and the path to the selected grid file populates in the Holdout Grids Event dialog box.  For  the Unregulated Grid box, follow the same steps as above in selecting the max depth grid representing the unregulated condition. Note, HEC-RAS grided outputs are stored under the HEC-RAS alternative name in the “ras” folder.
  4. If the user desires to link holdout *.dss time series output from HEC-ResSim, then from the bottom panel of the Holdout Grids Event dialog box, check the Use HEC-ResSim Calculated Holdout Time Series checkbox  (disabled, by default). If this option is not desired, then skip to Step 6.

    Selecting the checkbox enables the user to select a HEC-DSS file path and the computational output (E and F parts) for the HEC-ResSim holdout time series. From the HEC-ResSim Output box, click the button, and the Open browser window for HEC-DSS files opens . From the Open browser window, navigate to an existing *.dss dataset for the HEC-ResSim calculated holdout time series, select the HEC-DSS filename (e.g., simulation.dss) and click Open. The Open browser window closes, and the path to the selected *.dss file populates in the Holdout Grids Sections Event dialog box, in the HEC-ResSim Output box.

  5. Next, use the dropdown lists to complete the mapping to the linked *.dss file by selecting the correct E Part and Output F Part HEC-DSS identifiers. From the E Part list, select the correct *.dss time step for the hydraulic data. From the Output F Part list select the appropriate HEC-ResSim F part identifier.
  6. Click OK, the Holdout Grids Event dialog box  closes.

To Define Holdout - RAS HDF Events:

  1. From the Study Tree, from the Inundation Data folder, right-click on the appropriate inundation configuration name. From the shortcut menu , click Define Event; and the Holdout RAS HDF Event dialog box opens.
  2. From the Holdout RAS HDF Event dialog box enter a name for the event in the Event Name box . Below the Event Name box there are two panels.
  3. From the top panel the user must select the location of the HEC-RAS native HDF5 results for the appropriate plans. These are the results of the HEC-RAS plans for the regulated, unregulated, regulated without levee, and unregulated without levee conditions. 
    1. These results are found in the HEC-RAS project directory, and have the extension of p##.hdf where the number indicates what HEC-RAS plan the file belongs to.
  4. The users can also select the HEC-RAS terrain associated with these result files. The terrain file will have a .hdf extension. This is an optional input because the plan results files contain a relative path to their associated terrain. 
  5. From the top panel of the Holdout RAS HDF Event dialog box, click the  button next to each field. The Open browser window opens. Navigate to an existing HEC-RAS plan result file (eg *.p03.hdf) for each of the events and click Open. The Open browser window closes, and the path to the selected grid file populates in the Holdout RAS HDF Event dialog box. 
  6. From the bottom panel the user has the option link holdout HEC-DSS time series output from HEC-ResSim.
  7. If the user desires to link holdout *.dss time series output from HEC-ResSim, then from the bottom panel of the Holdout RAS HDF Event dialog box, check the Use HEC-ResSim Calculated Holdout Time Series checkbox  (disabled, by default). If this option is not desired, then skip to Step 9.

    Selecting the checkbox enables the user to select a HEC-DSS file path and the computational output (E and F parts) for the HEC-ResSim holdout time series. From the HEC-ResSim Output box, click the button, and the Open browser window for HEC-DSS files opens . From the Open browser window, navigate to an existing *.dss dataset for the HEC-ResSim calculated holdout time series, select the HEC-DSS filename (e.g., simulation.dss) and click Open. The Open browser window closes, and the path to the selected *.dss file populates in the HEC-ResSim Output box.

  8. Next, use the dropdown lists to complete the mapping to the linked *.dss file by selecting the correct E Part and Output F Part HEC-DSS identifiers. From the E Part list, select the correct *.dss time step for the hydraulic data. From the Output F Part list select the appropriate HEC-ResSim F part identifier.
  9. Click OK, the dialog box closes