Demand Deficit
When a calamity event is modeled, the total supplied demand may be less than the normal required demand. The difference between the calculated demand and the normal required demand is a demand deficit that is evaluated under a prescribed supply level threshold. The total system demand deficit under one possible calamity event j:
![](GUID-80E364F684DA45EA8EBC7F90542619A3-low.png)
Where
is the deficit demand at event j and St is the threshold of supply level. This formula provides the method for evaluating water supply level, element criticality, and modeling pressure dependent demand.