How do I remove problem reaches in Hydrology with the Scenario Edit Tool?
Problem reaches are reaches for which regression equations and/or data are not available. When computing the flood hazard, analysis for a specific return period or suite of return periods will not be available for reaches designated as ProblemReaches. Input of discharges will be required to develop the flood hazard grids for ProblemReaches.
If problem reaches occur, the message below will appear. If the user selects 'No' and later decides to remove problem reaches, the user can manually edit the scenario to exclude problem reaches as described below.
Click on the Hazard menu, Scenario > Edit. The Scenario Edit dialog will open and all of the reaches in the scenario will be highlighted in light blue. Click on the "Remove Problem Reaches" button (as seen in figure below), all of the problem reaches will be de-selected, and then click on the "Save selection" button. After the user clicks "OK," the new scenario will be mapped, shown in following figure.
If the Scenario is a riverine/coastal scenario, the Shoreline Characterization dialog will appear after edits are made to the scenario. The original parameters that were set for the shoreline(s) are saved if shoreline(s) weren't added/removed to the scenario. Users can select the 'Next' and 'Finish' buttons if they do not wish to modify the existing parameters.
The Scenario is now ready to start Hydraulics (Riverine\Delineate Floodplain ) for the ChosenReaches. (Hydrology does not need to be rerun since HAZUS has already computed discharges for non-ProblemReaches. If Hydrology is rerun, the results will remain the same since the ProblemReaches have been removed from the Scenario.)
Users also have the option to set HAZUS to automatically remove problem reaches (if they exist) from the scenario after the hydrologic process by checking the checkbox under Tools > Flood Options, as seen in the figure below.
If the user does not select to automatically remove problem reaches from the scenario at the end of the hydrologic process, a message will notify the user that problem reaches exist in the scenario and provide the option to remove the problem reaches from the scenario (with the click of one button), as seen in the first figure (see the "Remove Problem Reaches" window).
For additional information, see the HAZUS Flood User Manual as well as other HAZUS manuals and guidance materials available for download from HAZUS Resources on this site.
Need Additional Help?
Email: HAZUSGenHelp@nibs.org for general questions about HAZUS or
HAZUSFloodHelp@absconsulting.com for Flood Model questions.
Last Modified: Friday, 24-Jul-2009 16:11:24 EDT