In applications where the rainfall is important for the flow, you can include precipitation in your simulation. This is done either as a constant value or as a time series (type 0 data file), which then is applied to the entire model area, or as a time series of maps (type 2 data file) in which case each grid point is assigned its own value. The precipitation rate is specified in mm/day. You can use the Time Series Editor or the Grid Editor tool to create your precipitation data.
You can also use the precipitation facility to include Evaporation in your simulation. This is simply done by specifying a negative precipitation. However, in simulations with temperature variations the evaporation is calculated as part of the latent heat flux if the heat exchange option is selected (see Heat Exchange). Thus you should be careful not to specify evaporation from both options.
If you have selected the Heat Exchange option and you choose to include precipitation as net-precipitation, then evaporation obtained through the latent heat flux is not considered.