556 - WEHY Modeling and Calibration of Sacramento River Basin’s Sub-watersheds for their Use in a Hydrological Forecasting System

The Watershed Environmental Hydrology Hydro-Climate Model (WEHY-HCM) has been successfully applied to simulate important hydrological variables such as runoff and streamflows in various watersheds in the United States and the world. WEHY model uses dynamically downscaled atmospheric fields as inputs. In the WEHY model, a process-based fully physical model uses the downscaled atmospheric fields to estimate the discharge at each stream in the watershed. Therefore, given forecasted atmospheric fields, the WEHY model could be used to forecast the discharge at each stream. To this end, calibration of the WEHY model’s parameters related to the hydrology of the hillslopes and the stream channels needs to be done. This study shows the set-up, calibration, and validation of five sub-watersheds belonging to the Sacramento River Basin: Battle Creek (BCW), Mill Creek (MCW), Little Chico Creek (LCCW), Upper Butte Creek (UBCW), and Yuba Riber Basin (YRB). Climate Forecast System Reanalysis (CFSR) data were used as input for the dynamical downscaling from 1997 to 2006 for BCW, LCCW, and YRB, and 1998 to 2007 for MCW, and UBCW. The simulated precipitation, snow, and streamflows are compared with gauging stations available. Furthermore, the simulated precipitation is also compared with Parameter-elevation Regressions on Independent Slopes Model (PRISM) data. The results at each watershed are considered satisfactory, given that the Nash-Sutcliffe Efficiency is over 0.5 for most of the watersheds during the validation period, except for Battle Creek where we find a lower performance due to overestimation of the streamflow for a storm in 2006.