Considering drainages

In WaSiM (Richards), the parameterization of drainages is done by the definition of two separate grids:

• Drainage density contains horizontal distance between the drainage pipes for each cell
• Drainage depth contains the depth of drainage pipes in m for each cell

Drainages are handled by the model as additional ditches. They do not only drain the actual soil layer but also affect the soil water content of the layers above, because water can flow from the above layers into the drained layer after drainage. Drainage water is internally added to interflow.

Detailed description on Drainages can be found in the WaSiM manual.