DuHyd is used to separate the major (street flow) and the minor (pipe flow) hydrographs from a total hydrograph.
TABLE 3-8 DUHYD PARAMETERS
|Parameter Name||Description||Default Value|
|Major||NHYD of major system connection||Empty|
|Minor||NHYD of minor system connection||Empty|
|CINLET||The peak flow capture rate per inlet (m³/s or ft³/s)||0.06|
|NINLET|| The number of inlets in the drainage system which have the capture rate of CINLET.
The maximum flow that minor system capture equals CINLET × NINLET.
If the inflow of the DuHyd is less than or equal to this maximum flow (i.e. CINLET × NINLET), all these inflow will enter the minor system; otherwise, the flow that enters the minor system will be this maximum flow and the residual flow will enter the major system.
Tips: users can consider minor system as a sewer and major system as the overland flow.