Assessment and Calibration of the WRF-Hydro National Water Model Configuration for a Snowmelt Dominated Watershed in a Mountain Karst Region
Abstract
Physically based distributed hydrologic models capture the sensitivities to changes in climate or land surface properties and are widely used to understand the hydrological dynamics of a catchment. An example is the WRF-Hydro hydrologic model that represent the key physical processes between the land and atmosphere involved in streamflow generation from atmospheric forcing inputs. WRF-Hydro has been used as the framework for the National Water Model (NWM) to simulate hydrologic fluxes and storages at different spatial resolutions. We applied the WRF-Hydro, configured as the National Water Model to the Logan River watershed, a snowmelt dominated watershed with significant karst conduit subsurface/groundwater flow to examine the hydrological response of this watershed. Examining the preliminary results, we observe diurnal fluctuations in the modeled streamflow larger than for the observed values which suggests that subsurface flow in this Karst watershed may dampen input fluctuations, relative to simulations. To explore causes for the over simulated diurnal fluctuations, we examined the sensitivity of streamflow to different parameters involved in Noah-MP snow process and the WRF-Hydro subsurface model and investigated calibration of these parameters. Additionally, we examine whether these fluctuations are due to snowmelt, which could be resolved with a physically based snowmelt model, or due to subsurface flow which could be corrected by changing the groundwater bucket model representation. We evaluate whether accounting for a local calibration improves streamflow and snow water equivalent behavior simulated and also explore the benefit of implementing a physically based snowmelt model into the WRF-Hydro NWM model configuration. The geo-static inputs are obtained from the CUAHSI Subset tool that extracts NWM inputs (such as soil properties, land use, NOAH-MP parameters, channel parameters) for a watershed of interest, while meteorological forcing are obtained from the NWM archive at RENCI.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFM.H43I2135G
- Keywords:
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- 1816 Estimation and forecasting;
- HYDROLOGY;
- 1839 Hydrologic scaling;
- HYDROLOGY;
- 1843 Land/atmosphere interactions;
- HYDROLOGY;
- 1847 Modeling;
- HYDROLOGY