Sensitivity of the streamflow to dually-calibrated WRF-Hydro simulations in the Russian River Watershed

The Russian River watershed is a key area of interest for hydrological modeling as it is susceptible to frequent widespread flooding in the wintertime. The Center for Western Weather and Water Extremes (CW3E) has installed a suite of meteorological and hydrologic observing instrumentation at several sites in the upper Russian River in order to better capture the spatial and temporal variability of extreme precipitation and flooding in the area. During 2016-2017, 6 new soil moisture, 6 new streamflow, and 10 new precipitation instruments were deployed to observe the changes in hydrology depending on topography, soil type, stream geometry, etc.

The National Water Model is a current operational hydrological model that predicts streamflow over the CONUS. It is currently calibrated such that its free parameters are chosen based on matching the streamflow observations from the United States Geological Survey (USGS). Here, we will evaluate the impact of a dual-calibration to streamflow and soil moisture in the WRF-Hydro model specifically in the upper Russian watershed. The WRF-Hydro model is configured such that the singularly calibrated model matches that of the National Water Model operation. While leveraging the high density of observations in the Russian River watershed, we will examine the variability of calibration parameters with and without soil moisture and the impact on simulated streamflow volume, hydrograph peak timing, and soil moisture using several atmospheric river cases occurring in the following water year.