Create a Topo

The topo provides SMRF with the following static layers:

  1. Digital elevation model

  2. Vegetation type

  3. Vegetation height

  4. Vegetation extinction coefficient

  5. Vegetation optical transmissivity

  6. Basin mask (optional)

All these layers are stored in a netCDF file, typically referred to the topo.nc file.

Note

The topo.nc must have projection information. It’s just good practice.

Generating the topo

While the topo.nc file can be generated manually, a great option is to use basin_setup which creates a topo file that is compatible with SMRF and AWSM. To get a minimal topo file generated, the following are necessary:

  1. Pour point file in bna format

  2. Docker

basin_setup will perform auto basin delineation for the watershed and will output shapefiles for the basin and sub basins. Next, basin_setup will generate the topo.nc file with all the necessary variables for SMRF.

See the basin_setup documentation for more details.

Vegetation

The vegetation data comes from the LandFire dataset and contains the vegetation type and height at 30 meters. The vegetation is important in the following locations within SMRF

  1. Adds sheltering in the wind distribution in the Winstral wind model

  2. WindNinja log law roughness scaling

  3. Precipitation redistribution interference in the Winstral precipitation rescaling model

  4. Albedo decay date method

  5. Vegetation correction to solar radiation

  6. Vegetation correction to thermal radiation

Vegetation type is configured in SMRF as veg_<type>. For example, to add sheltering for vegetation type 3011, the configuration option veg_3011 will be set to the value needed, say 10.0. SMRF will apply the value 10.0 to any cells with vegetation type 3011.

Maxus file

If running SMRF with the Winstral wind model, a maxus (maximum upwind slope) file must be generated. The file is a calculation of the maximum upwind slope for many possible wind directions. To generate the maxus file, use the gen_maxus script.

gen_maxus --out_maxus=maxus.nc --sv_global 300 --sv_local=60 topo.nc

This will generate a maxus.nc which are the raw calulations for each direction. gen_maxus will also generate a maxus_100window.nc that averages the maxus values over a window, this averaged file is what typically is used for SMRF.

If using the Winstral precipitation rescaling method, the tbreak.nc is also required. Using the same command as above, adding the --make_tbreak will make this file.

gen_maxus --out_maxus=maxus.nc --sv_global 300 --sv_local=60 --make_tbreak --out_tbreak=tbreak.nc topo.nc
Installation Create a config file