4.1.2 Parameters
The model requires a parameter file (.par) to specify the spatial parameters for each HRU and the basin. For complex watersheds the easiest way to generate the .par file is with a GIS interface. A digital elevation model (DEM) and layers of ancillary data (soils, vegetation, etc.) are used to create a file like the one shown in Example 2. However, at the current stage of the model’s development the actual spatial representation of the HRUs was considered of lesser importantance, therefore the number of HRUs has been intentionally limited. As well, the GIS interface is not fully operational and spatial parameters are presently input into the model manually.
Parameters are required for the basin and the individual HRUs. It may be that GIS layers are available for some parameters or there may only be a single value available for the entire basin. This should be clearly defined and discussed between the user and modeller.
Sample Parameter file - Example 2.Description - to be added
######
basin basin_area 5
basin basin_name 'CRHM Basin Model'
basin hru_area 1 1 1 1 1
basin hru_ASL 0 0 0 0 0
basin hru_elev 637 637 637 637 637
basin hru_GSL 0 0 0 0 0
basin hru_lat 51.32 51.32 51.32 51.32 51.32
basin hru_names 'HRU' 'HRU2' 'HRU3' 'HRU4' 'HRU5'
crack fallstat 50 50 50 50 50
crack Major 5 5 5 5 5
ebsm delay_melt 0 0 0 0 0
ebsm nfactor 0 0 0 0 0
ebsm tfactor 2 2 2 2 2
evap evap_type 0 0 0 0 0
evap Ht 0.1 0.2 0.3 0.4 1
evap Zref 1.5 1.5 1.5 1.5 1.5
evap Zwind 10 10 10 10 10
global Time_Offset 0 0 0 0 0
netall hru_alb 0.17 0.17 0.17 0.17 0.17
net_rn F_Qg 0.2 0.2 0.2 0.2 0.2
net_rn F_Qs 0 0 0 0 0
obs catchadjust 0 0 0 0 0
obs tmax_allrain 0 0 0 0 0
obs tmax_allsnow 0 0 0 0 0
pbsm distrib 1 1 1 1 1
pbsm fetch 1000 1000 1000 1000 1000
pbsm Ht 0.1 0.2 0.3 0.4 1
route Kstorage 0 0 0 0 0
route Lag 0 0 0 0 0
route order 1 2 3 4 5
route whereto 0 0 0 0 0
smbal cov_type 3 3 3 3 3
smbal soil2gw_max 0 0 0 0 0
smbal soil_moist_init 187 187 187 187 187
smbal soil_moist_max 375 375 375 375 375
smbal soil_rechr_init 30 30 30 30 30
smbal soil_rechr_max 60 60 60 60 60
smbal soil_type 2 2 2 2 2
######
Sample data preparation table.
Table 1 shows a list of climate observations and spatial parameter requirements. The data provider should provide as much of this information as possible and submit a completed copy of the table to the user. If the data is available in units other than those stipulated in Table 1, the model can do the necessary conversions.
Table 1
| DATA | Units | Measurement ht. | Time Step | Time Period | Data Type/Source | Comments |
| Observations | ||||||
| temperature | degrees | |||||
| relative humidity | percent | |||||
| wind speed | m/s | |||||
| wind direction | degrees | |||||
| actual sunshine | hours | |||||
| incoming radiation flux | W/m2 | |||||
| reflected radiation flux | W/m2 | |||||
| net radiation flux | W/m2 | |||||
| depth of precipitation | mm | |||||
| precipitation form | unknown/snow/rain | |||||
| albedo | ||||||
| discharge rate | m3/s | |||||
| soil heat flux | W/m2 | |||||
| Parameters Basin/HRU | ||||||
| area | hectares | |||||
| slope | degrees | |||||
| aspect | degrees | |||||
| vegetation cover type | plus area | |||||
| soil type | plus area | |||||
| elevation | meters | |||||
| latitude | degrees | |||||
| vegetation cover height | meters | |||||
| vegetation cover density | percent | summer/winter | ||||
| interception storage capacity | mm | |||||
| leaf area index | m2/m2 | |||||
| fetch distance | Meters` | |||||
| soil properties | texture/storage/conductivity/rooting depth | |||||