Running NWM mode

[Jongkwan Kim]

Hi all,

I am trying to run the WRF-Hydro model with National Water Model mode. I have run the WPS and WRF-Hydro preprocessing GIS tool to generate the routing stacks with forecasting points. Then I am trying to run the model with the routing like below. I am using the Muskingum-Cunge as a channel routing and compound channel. For this method, I need to have some variables such as TopWdth, TopWdthCC, nCC, and BasinDim. However, I could not get these variables with WRF-Hydro preprocessing GIS tool. Do you have any ideas to figure this out? Thank you for your help. 

! Switch to activate subsurface routing...(0=no, 1=yes)
SUBRTSWCRT = 1

! Switch to activate surface overland flow routing...(0=no, 1=yes)
OVRTSWCRT = 1

! Specify overland flow routing option: 1=Seepest Descent (D8) 2=CASC2D (not active)
! NOTE: Currently subsurface flow is only steepest descent
rt_option = 1

! Switch to activate channel routing...(0=no, 1=yes)
CHANRTSWCRT = 1

! Specify channel routing option: 1=Muskingam-reach, 2=Musk.-Cunge-reach, 3=Diff.Wave-gridded
channel_option = 2

! Specify the reach file for reach-based routing options (e.g.: "Route_Link.nc")
route_link_f = "./DOMAIN/Route_Link.nc"

! If using channel_option=2, activate the compound channel formulation? (Default=.FALSE.)
! This option is only supported if using reach-based routing with UDMP=1.
compound_channel = .TRUE.

! Specify the lake parameter file (e.g.: "LAKEPARM.nc").
! Note REQUIRED if lakes are on.
!route_lake_f = "./DOMAIN/LAKEPARM.nc"

! Switch to activate baseflow bucket model...(0=none, 1=exp. bucket, 2=pass-through)
GWBASESWCRT = 1

! Groundwater/baseflow 2d mask specified on land surface model grid (e.g.: "GWBASINS.nc")
!Note: Only required if baseflow  model is active (1 or 2) and UDMP_OPT=0.
!gwbasmskfil = "./DOMAIN/GWBASINS.nc"

! Groundwater bucket parameter file (e.g.: "GWBUCKPARM.nc")
GWBUCKPARM_file = "./DOMAIN/GWBUCKPARM.nc"

! User defined mapping, such NHDPlus: 0=no (default), 1=yes
UDMP_OPT = 1

! If on, specify the user-defined mapping file (e.g.: "spatialweights.nc")

udmap_file = "./DOMAIN/spatialweights.nc" 

[Kevin]

Jongkwan,

I am afraid that the WRF-Hydro GIS Pre-processing tools are unable at this time to generate the files necessary to run the NWM configuration of WRF-Hydro. The NOAA National Water Model uses the pre-existing NHDPlus as its hydrography network. This requires sets of custom files that map between the vector network or catchments to the model grid. Tools to generate these files are not publicly available. However, you can request a 'cutout' of NWM for your domain which will include the necessary domain files for running the NWM configuration of WRF-Hydro using NWM input files. Please use the WRF-Hydro support request form (link below) for requesting your NWM subset. Subsets may be made from a bounding box, or NHDPlus flowline ComID.

https://ral.ucar.edu/projects/wrf_hydro/contact

Thanks,

Kevin

[Jongkwan Kim]

Kevin,

Thanks so much for your detailed answer. I have one more question. I want to run the WRF-Hydro model using channel routing option 2 : Muskingum-Cunge. As far as I know, for this I need to have some variables such as TopWdth, TopWdthCC and nCC within the Route_Link.nc file and BasinDim within the GWBUCKPARM.nc file. Do you have any ideas to get these variables? 

Best,

Jongkwan

[Kevin Sampson]

Jongkwan,

The information will be in a forthcoming paper, but for the National Water Model v2.0 and v2.1, we populated compound channel variables (TopWdth, BtmWdth, ChSlp) using CONUS regression equations on contributing area from Blackburn-Lynch (2017), citation below: 

Blackburn-Lynch, W., Agouridis, C.T., and Barton, C. 2017. Development of Regional Curves    for Hydrologic Landscape Regions (HLR) in the Contiguous United States. Journal of the      American Water Resources Association, 53(4):903–928, ISSN 17521688. doi:          10.1111/1752-1688.12540. URL http://doi.wiley.com/10.1111/1752-1688.12540.

For the compound channel parameters, we also used a multiplier of 3.0 on TopWdth for the TopWdthCC parameter, and a multiplier of 2.0 on the main channel Mannings N (n) to get the compound channel Mannings N (nCC).

Kevin

Kevin Sampson, GISP
Associate Scientist
National Center for Atmospheric Research
P.O. Box 3000 Boulder, CO  80307-3000
Tel: 303.497.8121