US EPA

3238278 

Journal Article 

Coupling HEC-HMS with atmospheric models for prediction of watershed runoff 

Anderson, ML; Chen, ZQ; Kavvas, ML; Feldman, A 

2002 

Yes 

Journal of Hydrologic Engineering
ISSN: 1084-0699 

7 

4 

312-318 

10.1061/(ASCE)1084-0699(2002)7:4(312) 

WOS:000176286700004 

The operation of reservoirs in the Sierra Nevada mountains
of California for flood control relies on forecasts of reservoir inflows. In the past, accurate
forecasts of the reservoir inflows resulting from watershed runoff have been made, but only after
the water has entered the main channel. During flooding events, this limits the amount of time
available for the implementation of emergency management procedures. Translating precipitation
forecasts into runoff forecasts can greatly improve the runoff-forecast lead time. The
operational National Center for Environmental Prediction Eta model provides 48-h-ahead forecasts
of precipitation in 6-h intervals in a 40 X 40 km gridded form. In this study, the mesoscale
model, MM5, is used to transfer the Eta forecast data down to the appropriate space and time
scales required to link the Eta model precipitation forecast results to the watershed model,
HEC-HMS, for runoff prediction. An initial diagnostic study of this procedure has been performed
on the Calaveras River watershed in Northern California. Initial results indicate that: (1) model
parameterization choice in MM5 is necessary to refine the precipitation forecasts; (2) the method
shows promise for generating 48-h-ahead forecasts of reservoir inflows; and (3) calibration of
the HEC-HMS model with distributed precipitation is necessary for this methodology. This paper
presents the study results along with a discussion of the methodology. 

runoff forecasting; watersheds; California