Network vulnerability is a measure of the performance of the water distribution system and is defined as the probability of satisfying nodal demands and minimum pressures for various possible pipe failures (breaks) in the water distribution system. The Vulnerability analysis is conducted by breaking each pipe in the system, one at a time, and then determining for each case if the pressures and flows can be satisfied with the pipe out of service. A report showing the effects of each pipe break is then generated at the completion of a Vulnerability analysis.
Flexibility is allowed when selecting pipe segments for reliability assessment. You can launch a Vulnerability analysis run for:
The entire network.
Only those pipe segments in the current network domain.
Only those pipe segments graphically selected.
All critical pipes that will result in the system hydraulic failure are automatically identified offering basis for determining the level of system reliability/redundancy. Hydraulic failure in this context refers to the inability of the system to meet imposed demand flows and minimal pressures.
Dead end pipes and nodes upstream and downstream of both valves and pumps can also be excluded from analysis at the user request. Similarly, minimum allowable pressures can be defined for any set of junction nodes or pressure zones in the system.
Pipes with check valves and pipes connected to tanks will not be considered during a network Vulnerability assessment run.
Pipe Break Selection
You have the option of excluding the following elements from a Vulnerability analysis:
Exclude Dead End - Exclude dead end pipe sections from the Vulnerability analysis.
All - All pipes in the current project will be analyzed during the Vulnerability simulation.
Domain - Use this to create a domain to conduct a Vulnerability analysis. Use the Edit Domain button to create a domain if one is not already present. Use the Edit Domain button to create, modify, and delete pipe elements to be included in a domain prior to a Vulnerability analysis.
Selection - Graphically select pipes to conduct a Vulnerability analysis. Use the Edit Selection button to graphically select the desired pipe(s). Use the Selection button to select the pipes in the map view.
Select a time from which to conduct the simulation. The simulation will run from hour 0:00 to the time specified with the Select Time dialog box. For example, if hour 13:00 is specified the Fire analysis will be run from hour 0:00 to 13:00 hours.
Select Time - The Select Time button will display the select time slider. Use the slider to select a time from which to conduct the simulation.
Save to Selection Set
Critical Pipes - Specify a selection set to save critical pipes during the Vulnerability analysis. These are the pipes that have been found to be essential in order to maintain either minimal demand flows or minimal pressures. Use the Browse button to open the selection Set Manager. You can also specify a color to see these pipes at the bottom of the dialog box after selecting the Update Map button.
Non Critical Pipes - Specify a selection set to save non-critical pipes during the Vulnerability analysis. Use the Browse button to open the selection Set Manager. You can also specify a color for these pipes at the bottom of the dialog box.
Pressure Criteria - The Pressure Criteria dialog box allows you to specify minimum pressures to be maintained during a Vulnerability analysis.
Run - Run the Vulnerability analysis simulation with pressures based on the minimum pressures specified and utilizing the set of system distribution pipes as specified.
Report - This button generates a report of the Vulnerability analysis.
Update Map - Click on the Update Map button to view all nodes that have received water from the source node(s) after concluding a simulation.
Options - The Options button is used for assigning the GIS-based layer to be used for conducting a customer notification. Customer notification is not used for the Fire analysis.
Reset Map - Click on the Reset Map button to reset the Map display to its default state.
Close - Click Close to close the Protector dialog box. To conduct another water security analysis, simply click on another analysis tab in the Protector dialog box.