Evaluation of Potential Evapotranspiration from a Hydrologic Model on a National Scale

Thursday, 18 December 2014
Kirsti Anna Hakala1, Lauren Hay1 and Steven L Markstrom2, (1)USGS Colorado Water Science Center Lakewood, Lakewood, CO, United States, (2)USGS, National Research Program, Baltimore, MD, United States
The US Geological Survey has developed a National Hydrologic Model (NHM) to support coordinated, comprehensive and consistent hydrologic model development and facilitate the application of simulations on the scale of the continental US. The NHM has a consistent geospatial fabric for modeling, consisting of over 100,000 hydrologic response units (HRUs). Each HRU requires accurate parameter estimates, some of which are attained from automated calibration. However, improved calibration can be achieved by initially utilizing as many parameters as possible from national data sets. This presentation investigates the effectiveness of calculating potential evapotranspiration (PET) parameters based on mean monthly values from the NOAA PET Atlas. Additional PET products are then used to evaluate the PET parameters. Effectively utilizing existing national-scale data sets can simplify the effort in establishing a robust NHM.