HEC Snyder Unit Hydrograph Model

The HEC Snyder (Snyder Alameda) unit hydrograph routing model is based on the standard Snyder unit hydrograph method documented in the Hydrological Modeling System HEC-HMS Technical Reference Manual, US Army Corps of Engineers, 2000, CPD-74B.

It uses the same equations as the Snyder Unit Hydrograph Model but generates an equivalent Clark UH from the computed UH peak and time to peak for Snyder.

The Lag Time, TL and Peaking Coefficient, Cp (used to calculate peak discharge) are specified in the Subcatchment Grid Window of the Subcatchments Grid or on the Subcatchment Property Sheet. The Unit Hydrograph Definition for the subcatchment must be set to Snyder.

For further information, see the Hydrological Modeling System HEC-HMS Technical Reference Manual.