Watch Points

Watch points are used to monitor specific cells that the user is primarily interested in. Setting watch points provides a convenient way to obtain hydrographs at multiple locations without having to solve Vflo™ for each individual cell. Use the Watch Points list, located in the Cell List pane on the lower left of the Vflo™ interface, to establish watch points (see details below). After watch points are established, use the Analyze Basin SolveCell.png tool, press the shortcut key F12, or select Analysis | Analyze Basin to solve for all established watch points (see Solving all watch points for details).

Important uses of watch points include:

  1. Calibration: In calibration, watch points may be established for stream gauge locations where observed data is available. In this way, the Analyze Basin command can be used to generate hydrographs for all cells with observed data at once, allowing efficient comparison of simulated and observed hydrographs.
  2. Flood Watch: A Flood Watch Report is generated when watch points are solved, featuring graphic notifications when stage results are higher than established Flood Watch levels.
  3. Sensitivity Analyst: Sensitivity Analyst results are output for established watch points, only. Establishing watch points is an essential preparatory step for using Sensitivity Analyst.
  4. Continuous Simulator: Continuous Simulator results are output for established watch points, only. Thus, establishing watch points is an essential preparatory step for using Continuous Simulator.

Establishing watch points

Once a cell is made a watch point, it will appear in the Watch Points list. Each row of the Watch Points list contains the Name, Coordinates, Warning Level, and Watch Level of an established watch point.

Step-by-step instructions

1. Open the Watch Points list.

Find the Watch Points list in the Cell List pane, located on the lower left of the Vflo™ interface.

2. Select the cell that is to be a watch point.

One method of determining the location of potential watch points within the Vflo™ model is to load a shapefile with the points of interest. The shapefile must be in the same projection as the base parameter maps used in AutoBOP or GIS, or be accompanied by a PRJ projection file. In Vflo™, zoom to the point of interest, determine the closest grid cell, then add the cell as a watch point, as described herein.

3. Click the Add new cell  button.

If the selected cell has no inputs, the error message shown at right will pop up. This is because Flood Watch levels and hydrograph results cannot be generated for cells with no flow input. Click OK, then repeat step 2, selecting an appropriate cell.
If the cell does have inputs, then the cell will appear in the Watch Points list.

4. If Flood Watch functionality is desired, enter Warning Level and Watch Level values (optional).

Warning Level and Watch Level values should be the stage values at which flood warnings are needed. Values must be entered in either meters (metric) or feet (US Customary). To enter values, double click on the Warning Level or Watch Level field and type in the desired threshold value.

5. To remove a cell from the Watch Points list, select the cell row, then click the Remove cell  button.

The cell will no longer be a watch point.

6. To zoom to a watch point cell, select the cell row in the Watch Points list, then click the Zoom  button.

The Main Display will zoom to the selected watch point.

Solving watch points

See Solving Vflo™.