The DSS file “split.dss” contains only the input for an unsteady HecRAS analysis. Below is a screenshot of the main HecDSSVue menu, with the first record (with Part C as “FLOW”) representing the upstream boundary, a storm hydrograph. The second record (with Part C as “STAGE” represents the downstream boundary, a tidal elevation hydrograph.
The user may easily perform a number of data manipulations with the time-series data. For example, the screenshot below shows the second record (for the tidal stage hydrograph) having been selected, and the user choosing “Math Functions...” from the Tools pull-down menu. While running HecDSSVue on your own machine, you can try the procedures shown in the following screenshots.
The “Math Functions...” selection brings up the window shown in the screenshot below. Of the many math manipulations available, two commonly used options are, from the Operator selection window, “Add” and “Multiply”. If the user first multiplies the tidal record by 1.1 the result is that tide peaks are ten percent higher and the tide troughs are ten percent lower. If the user then adds 1.5 feet to the tidal record the entire hydrograph is raised by that amount. The user may save the manipulated record to a separate pathname. Under the math menu screenshot, below, is an example plot of the original tidal dataset (blue) with the record that has been manipulated (red).
The following screenshot shows a plot of the original tidal record (blue) with the manipulated record (red). Note that the original data was first multiplied by 1.1 (a ten percent increase of peaks and decrease of troughs) and then the entire record was raised by 1.5 feet. This manipulation of five days of data (at a 6-minute timestep) took seconds.