Inflow Hydrograph (user-provided hydrograph) property sheet
This window enables you to enter a user-provided hydrograph at a pit. You have a choice of applying this above the inlet at the surface, or inside the pit.
You need to specify the duration of this hydrograph and the time step between ordinates. This can be longer than the time step used for calculation – DRAINS will interpolate values during calculations. The actual values are entered in a similar way to the ordinates of a rainfall pattern hyetograph in the Rainfall Data property sheet. You simple enter the values in the spin box and move the arrows. The hydrograph is displayed as you go.
There is also the option of transferring a hydrograph from a spreadsheet program using the Paste button shown in this box. You need to run the spreadsheet at the same time as DRAINS, and to set up data in two columns. The first should contain times in minutes, at equal intervals; the second should contain the flowrates.
You need to copy the two entire columns, not just the cells containing the numbers. If you then go to the DRAINS window, you can enter the hydrograph by clicking the Paste button.