The name of the routing unit is not used by the model.

The pointer to the routing unit definition file is a foreign key referencing in .

The pointer to the topography file is a foreign key referencing in .

The topography variables for Routing Units are used to compute time of concentration for sub-daily routing.

The ID of the Routing Unit is a primary key referenced by in . All IDs in the rout_unit.rtu file must be unique.

The ID of the Routing Unit is a primary key referenced by in . All IDs in the rout_unit.def file must be unique.

The pointer to the field file is a foreign key referencing in .

The name of the Routing Unit is not used by the model.

If each element in the Routing Unit is listed individually, the number of columns to read will equal the number of elements in the Routing Unit. However, if there are several elements with consecutive numbers in a Routing Unit, they can be listed by specifying the first one in one column and the last one with a hyphen in front of it in the next column.

If = 1, there can be only one element in the Routing Unit, whose ID ( in ) is specified in this column. If > 1, this column is followed by additional columns listing the elements included in the Routing Unit, but those columns will not have a header. If there are several elements with consecutive numbers in a Routing Unit, they can be listed by specifying the first one in one column and the last one with a hyphen in front of it in the next column.

The name of the element is not used by the model.

The object ID of the element is a foreign key referencing the ID of the object in its file:

The following object types can be elements in a Routing Unit:

• another rtu

• hru

• res

• aqu

• sdc

• rec

The ID of the element is a primary key referenced by in . All IDs in the rout_unit.ele file must be unique.

Routing Units are the spatial units in SWAT+ that allow us to lump outputs and route them to any other spatial object. Routing Units don't have a lot of properties as they mostly serve the purpose of collecting hydrographs and the simulation of the processes generating those is controlled by the properties of the individual elements within a routing unit.

• rout_unit.rtu references other files specifying the elements that are part of a Routing Unit and its topographic and field properties.

• rout_unit.def specifies which elements a Routing Unit contains.

• lists all elements that are part of a Routing Unit.