Tributary Type Codes
 
The following coding scheme is used to classify source types:
 
 1 - Gauged Tributary -    inflow volumes & concentrations are directly measured or independently estimated
 2 - Ungauged Tributary - inflow volumes and concentrations are estimated from land use & specified export coefficients
 3 - Point Source
 4 - Withdrawal or Outflow
 5 - Diffusive Source
 
Tributary types are selected from a drop-down list box on the tributary edit screen.

Type=5 is used to specify diffusive exchange with a reservoir areawhich is not represented in the segment network. The flow represents diffusive exchange between this area and the specified segment. The input concentrations represent the average measured nutrient concentrations for the area. This option can be used to simulate a reservoir arm or embayment without simulating the entire reservoir (see sample input files Case ? & St Albans Bay).

In Bathtub version 5.x, Type=5 was used to specify internal loads and Type=6 was used to specify a diffusive source.  In Version 6.x, internal loads are specified on the segment input screen.  These changes are automatically made when a Version 5.x input file is translated.

See further discussion of this topic.