Enhancing the structure of WRF-Hydro-Hydologic Model for semi-arid environments

Authors: LAHMERS, T.M. - University Of Arizona; GUPTA, H.V. - University Of Arizona; HAZENBERG, P. - University Of Arizona; CASTRO, C.L. - University Of Arizona; GOCHIS, D.J. - National Center For Atmospheric Research (NCAR); YATES, D. - National Center For Atmospheric Research (NCAR); DUGGER, A. - National Center For Atmospheric Research (NCAR); Goodrich, David - Dave

Submitted to: Journal of Hydrometeorology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/5/2019
Publication Date: 4/25/2019
Citation: Lahmers, T., Gupta, H., Hazenberg, P., Castro, C., Gochis, D., Yates, D., Dugger, A., Goodrich, D.C. 2019. Enhancing the structure of WRF-Hydro-Hydologic Model for semi-arid environments. Journal of Hydrometeorology. 20:691-714. https://doi.org/10.1175/JHM-D-18-0064.1.
DOI: https://doi.org/10.1175/JHM-D-18-0064.1

Interpretive Summary: The National Weather Service implemented the National Water Model (NWM) to simulate and forecast streamflow, soil moisture, throughout the contiguous United States. However, the model does not treat channel infiltration, an important component of the water balance of the semi-arid western United States where dry stream beds can absorb large amounts of runoff. A method to treat channel infiltration, based on the USDA-ARS KINEROS2 watershed model, was implemented in the National Water Model. The updated National Water Model with channel infiltration resulted in improved runoff simulations and forecasting in the USDA-ARS Walnut Gulch Experimental Watershed (part of the Long Term Agroecosystems Research network) and the nearby Babocomari River, both in southeastern Arizona.

Technical Abstract: The NOAA National Weather Service’s Office of Water Prediction implemented the operational National Water Model (NWM) in August 2016 to simulate and forecast streamflow, soil moisture, and other model states throughout the Contiguous US. However, the operational model does not currently resolve channel infiltration, an important component of the water balance of the semi-arid western US. Here, we demonstrate the benefit of implementing a conceptual channel infiltration function into the NWM. After calibration, the updated WRF-Hydro model provides improved flow simulation and forecasting in the Walnut Gulch Experimental Watershed and the Babocomari River in southeast Arizona. The channel infiltration function implemented is based on that of the KINEROS2 semi-distributed hydrologic model, previously tested throughout the southwest U.S. for flash flood forecasting. Results show that including channel infiltration results in a physically realistic hydrologic response at the USDA-ARS Walnut Gulch Experimental Watershed, when the model is forced with high resolution gauge-based precipitation. The value of channel losses is also demonstrated in the Babocomari Basin, where the drainage area is greater, and the cumulative effect of channel infiltration is more important. Overall, accounting for channel infiltration loss improves the streamflow behavior simulated by the calibrated model, and generally preserves modeled soil moisture correlation coefficients.