A monthly-pattern demand node allows you to specify a demand as monthly values in megalitres. This is a simple representation supporting the needs of demand and supply analysis. The demand from nodes is accumulated in a bottom-up pass to the identified supply storage, from which water is released (if possible) at the appropriate time to meet the demand. You can configure the model by right-clicking Demand Models and choosing Monthly Pattern from the contextual menu (Figure 1).
Demand can be specified as either:
Monthly values in the Order per month fields; or
As a percentage of a total amount. Enable the Use Annual Total checkbox and specify the total demand in the respective field. You can then specify what percentage and share of this total amount to allocate each month.
You can enter monthly demand values directly or load the data from a comma-separated (.CSV) file (format shown in Table 1). For simulation over smaller time-steps, the monthly volume is evenly distributed across the time-steps for that month.
Note: For a monthly pattern demand model, orders are in units of ML, and are averaged over an entire month for a daily value. To ensure that there is no discrepancy in orders between leap and non-leap years, define a time series demand model with a function as the input data source. Refer to the Time Series Demand model for more information.
Refer to Return flows for configuring Return flows in the model.
Figure 1. Water User node (Monthly Pattern, Demand)
Table 1. Water User node (Monthly Pattern, data file format)
Order per Month (ML)
Where: month is the first three characters of the month name with a leading capital letter (eg "Jan")
order is the order in megalitres for the corresponding month.