Not sure about the rainfall units in the wetland water balance of ACRU. I have looked at the ACRU4 user manual which comes with the modelling tool installation and a dissertation covering the wetland HRU model structure (Gray, 2011) but didn’t see reference to the units. The units are also not mentioned in the drop-down list of variables in the output selector. Please advise?
In both input and output files, the rainfall is in mm.
Relative to other HRUs, the rainfall depths are the same, but the volumes are different because it depends on the HRU area. For this reason, it is easier to convert the rainfall depth to a volume if you are estimating a water balance.
To convert the depth of rainfall falling on the wetland HRU to a volume, it would be [rainfall depth (mm) / 1000 ] * wetland area (km2)
To work with the rainfall as a depth, the wetland rainfall depth is calculated as an area-weighted value, wetland rainfall depth (mm) = subcatchment rainfall (mm) * [wetland area (km2) / subcatchment area (km2) ]