snarea_thresh (nhru)

PRMS Parameter Name(s): snarea_thresh

BAGIS-P Model Toolbox: bagis_p_climate_methods.tbx

BAGIS-P Model Name: snarea_thresh

Field Name(s):

• snarea_thresh

Parameter Description: The minimum snow-pack water equivalent for HRUs expressed in cubic inches. The equation is based on Weasel formula, which is:

snarea_thresh = (Median_Elevation_Ft - Min_AOI_Elevation) x 0.005

0.005 is the rate of the number of increase of SWE (in inches) per 1000 meters increase in elevation.

Methods:

• 1. Make integer DEM layer using Int.

  2. Get MEDIAN elevation (m) for each HRU using Zonal Statistics as table.

  3. Copy MEDIAN field values to the parameter table under the new field, “fld_snarea_thresh”.

  4. Convert units to feet.

  5. Calculate the MINIMUM elevation for the AOI grid using Zonal Statistics as Table.

  6. Use the following expression in Calculate Field to update the snarea_thresh field:

([snarea_thresh] - (AOIMinElev * 3.28084)) * 0.001522

BAGIS-P GUI Example: