NWM V3.0 Alaska Domain Expansion: Development of a Geospatial Hydrologic Data-fabric for Hydrologic Prediction in South Central Alaska

Abstract:

The NOAA National Water Model (NWM) is a continental-scale operational hydrologic prediction system based on the community WRF-Hydro hydrological modeling system. Currently, the NWM is capable of producing forecasts of streamflow and other hydrologic states for the contiguous United States, Hawaii, and Puerto Rico. The NWM v3.0 is an upcoming major upgrade of the model currently under development at the National Center for Atmospheric Research (NCAR) and the NOAA Office of Water Prediction, and will include a new spatial domain with coverage over the Cook Inlet and Copper River watersheds in South-Central Alaska. NWM Alaska will utilize a gridded framework similar to preceding NWM implementations, with a 1km land surface model grid and 250m routing sub-grid. However, v3.0 will be the first NWM version utilizing a hydrography network primarily consisting of NHDPlus High Resolution (HR) streams, catchments, and waterbodies. The recently completed NHDPlus HR (Beta) for Cook Inlet is employed, which represents surface hydrologic features digitized at 1:24,000 scale. A synthetic network of high-resolution hydrologic vector features including flowlines and catchment polygons was derived for the neighboring Copper River basin using 5m IfSAR elevation data. This presentation will detail the datasets selected and approaches taken to build the geospatial hydrologic fabric and accompanying geophysical parameters used as input to the NWM v3.0 implementation for South-Central Alaska.