Evaluating Full Physics and Conceptual Hydrological Model Soil Moisture Simulations with Observations

Evaluating Full Physics and Conceptual Hydrological Model Soil Moisture Simulations with Observations

Robert J Zamora, Andrea R Thorstensen, and Rob Cifelli

Full physics hydrological models such as the National Center for Atmospheric Research Weather Research and Forecasting Model Hydrological modeling extension package (NCAR-WRF-Hydro) are now available to both the research and operational segments of the hydrological community. Both full physics, and conceptual hydrological models require a priori specification of the model parameters that control infiltration rates, evapotranspiration, hydraulic conductivity etc. In typical applications these parameters are modified after comparing the simulated streamflow with the observed hydrographs in an effort to optimize model performance. These initial “out of the box” simulations of streamflow and soil moisture can represent either worst case scenarios or benchmarks of model performance. In this work we compare soil moisture observations from the NOAA Physical Sciences Division (PSD) Russian River Basin soil moisture network with simulations obtained from open runs of the National Weather Service's Hydrology Laboratory Research Distributed Hydrologic Model (HL-RDHM) Sacramento Heat Transfer Model (SAC-HT), the HL-RDHM Enhanced EvapoTranspiration (SAC-HTET) model,  and WRF-Hydro. The models were forced using precipitation and surface temperature fields provided by the NWS California River Forecast Center. No attempts were made to change either the forcing data or the a priori parameters supplied with the models by the NWS National Water Center (NWC) or NCAR. This work focuses on a three year period from 1 November 2010 – 1 November 2013.