Difference between revisions of "Snow Card Inputs - Optional"
From Gsshawiki
| Line 62: | Line 62: | ||
Example file when using '''NWSRFS_ELEV_SNOW'''<br> | Example file when using '''NWSRFS_ELEV_SNOW'''<br> | ||
[[File:Band_NWSRFS.jpg]]<br> | [[File:Band_NWSRFS.jpg]]<br> | ||
| + | Elevations are in meters, all other values are in their standard formats. | ||
<br><br> | <br><br> | ||
Revision as of 19:05, 28 November 2012
The following tables list all project file cards pertaining to snow accumulation, melt, and melt-water transport.
Cards calling which snow melt algorithm to use
| Melt Method | Card | Description |
|---|---|---|
| Hybrid Energy Balance | default (no card required) |
The Hybrid Energy Balance Method for melting snow is the default, so it is utilized if NWSRFS_SNOW and EB_SNOW are not present in the Project File. |
| Temperature Index | NWSRFS_SNOW |
The Temperature Index Method for melting snow is utilized if this card is present in the Project File. |
| Energy Balance | EB_SNOW |
The Energy Balance Method for melting snow is utilized if this card is present in the Project File. |
Cards Associated with All Three Melt Methods
| Card | Argument | Units | Description |
|---|---|---|---|
NWSRFS_SCF ##.## |
real | fraction | Snow Cover Factor (adjusts for mis-readings in the gage data (see Continuous:Snowfall_Accumulation_and_Melting). |
SNOW_TEMP_BASE ##.## |
real | °C | Base Temperature (MBASE) at which melt begins in snow. |
SNOW_NO_INFILTRATE |
This option prevents infiltration in any cell containing snow. | ||
INIT_SWE_DEPTH #.# or File |
real or File | m | Initializes the snow water equivalent (SWE) for the entire model. If a value is specified the entire model initializes with that value of SWE. A map file may also be specified. The projection and spatial coordinates must be the same as the model. An example input file is shown below. |
SNOW_SWE_FILE ***.swe |
File | m | Outputs time-series snow water equivalent maps (similar to DEP file). |
Example file when using INIT_SWE_DEPTH
Cards Associated with BOTH Hybrid Energy Balance and Temperature Index Methods
| Card | Argument | Units | Description |
|---|---|---|---|
NWSRFS_FR_USE ##.## |
real | fraction | Specifies the fraction of precipitation in the form of rain when the temperature in the cell drops below MBASE. |
NWSRFS_TIPM ##.## |
real | Snow Cover Thermal Gradient | |
NWSRFS_NMF ##.## |
real | mm/°C/dt | Negative Melt Factor. |
NWSRFS_FUA ##.## |
real | Empirical Wind Function Factor. | |
NWSRFS_PLWHC ##.## |
real | % | Percent Liquid Water Holding Capacity. |
NWSRFS_ELEV_SNOW File |
File | depends on parameter | This card allows some of the parameters related to snow to be varied depending on elevation using elevation bands. The format of the input file is shown below. |
Example file when using NWSRFS_ELEV_SNOW
Elevations are in meters, all other values are in their standard formats.
Cards Associated with JUST Temperature Index Method
| Card | Argument | Units | Description |
|---|---|---|---|
NWSRFS_MF_MAX ##.## |
real | mm/°C/dt | Maximum Melt Factor, only works with NWSRFS_SNOW. |
NWSRFS_MF_MIN ##.## |
real | mm/°C/dt | Minimum Melt Factor, only works with NWSRFS_SNOW. |
Cards Associated with Vertical Melt Water Transport (Vertical MWT)
| Card | Argument | Units | Description |
|---|---|---|---|
SNAP_RETENTION |
Uses the SNAP model (Albert & Krajeski, 1998) to simulate the vertical transport of melt-water through the snow pack (Vertical MWT). | ||
VERT_SNOW_RETENTION |
Uses the SNAP model (Albert & Krajeski, 1998) to simulate the vertical transport of melt-water through the snow pack (Vertical MWT), but also distributes the melt incrementally over an hour instead of abruptly at every timestep that SNAP is run (which is hourly). |
Cards Associated with Lateral Melt Water Transport (Lateral MWT)
| Card | Argument | Units | Description |
|---|---|---|---|
SNOW_DARCY ##.## |
real | m s-1 | Simulates the lateral transport of melt-water through the snow pack based on work by Colbeck (1974) (Lateral MWT). The user specifies the initial hydraulic conductivity of the snow pack (m s-1), but the hydraulic conductivity changes with time according to the SNAP model (Albert & Krajeski, 1998). |
SNOW_REYNOLDS ##.## |
real | Reynolds Number at which flow simulation switches from Darcian to regular Overland. Only effects cells covered by snow and only works when SNOW_DARCY card present in Project File. |
Cards Associated with Orographic Effects
| Card | Argument | Units | Description |
|---|---|---|---|
HMET_OROG_GAGES ***.txt |
File | see Orographic Effects | Adjusts the temperature in each cell based on elevation differences between the cell and multiple gage sites. The file must have a specific format as shown in Orographic Effects. |
OROGVAR_HMET |
Adjusts the temperature in each cell based on elevation differences between the cell and the gage site (Orographic Effects). Only works when HMET_ELEV_GAGE and HMET_LAPSE_RATE cards present in Project File. This is an additional option if you do not want to use HMET_OROG_GAGES. Only one temperature gage used for this option. | ||
HMET_ELEV_GAGE ##.## |
real | m | Elevation (m) of the gage site where temperature is measured. Only works when OROGVAR_HMET and HMET_LAPSE_RATE cards present in Project File. |
HMET_LAPSE_RATE ##.## |
real | °C km-1 | Dry adiabatic lapse rate of the area modeled. Only works when OROGVAR_HMET and HMET_ELEV_GAGE cards present in Project File. |
GSSHA User's Manual
- 3 Project File
- 3.1 Required Inputs
- 3.2 Mapping Table – Optional
- 3.3 Overland Flow – Required
- 3.4 Interception – Optional
- 3.5 Rainfall Input and Options – Required
- 3.6 Infiltration – Optional
- 3.7 Channel Routing – Optional
- 3.8 Continuous Simulations – Optional
- 3.9 Saturated Groundwater Flow – Optional
- 3.10 Soil Erosion – Optional
- 3.11 Constituent Transport – Optional
- 3.12 Subsurface Drainage Network – Optional
- 3.13 Output Files – Required
