Coupling HEC-HMS with Atmospheric Models for Prediction of Watershed Runoff

Abstract

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