Hydrological Parameters - Soil Infiltration¶
Wetting loss [m] is a one-off loss, accounting for wetting of the catchment surface.
The default value for all surface types is 5.00E10-5 m.
Storage loss [m] is a one-off loss, which defines the precipitation depth required for filling the depressions on the catchment surface prior to occurrence of runoff.
The default value depends on the surface type (see the default hydrological parameters for Kinematic wave surface runoff model)
Start infiltration rate [m/s] defines the maximum rate of infiltration (Horton) for the specific surface type.
The default value depends on the surface type (see the default hydrological parameters for Kinematic wave surface runoff model).
End infiltration rate [m/s] defines the minimum rate of infiltration (Horton) for the specific surface type.
The default value depends on the surface type (see the default hydrological parameters for Kinematic wave surface runoff model).
Wet Horton Exponent [s-1] is time factor “characteristic soil parameter”. It determines the dynamics of the infiltration capacity rate reduction over time during wet period. The actual infiltration capacity is made dependent of time since the rainfall start only.
The default value depends on the surface type (see the default hydrological parameters for Kinematic wave surface runoff model).
Dry Horton Exponent [s-1] is a time factor used in the “inverse Horton's equation”, defining the rate of the soil infiltration capacity recovery after a rainfall, i.e. in a drying period.
The default value depends on the surface type (see the default hydrological parameters for Kinematic wave surface runoff model).
Manning’s number [m1/3s-1] describes roughness of the catchment surface, used in hydraulic routing of the runoff (Manning's formula).
The default values depend on the catchment surface category (see the default hydrological parameters for Kinematic wave surface runoff model).
Table: Default hydrological parameters for Kinematic wave surface runoff model.
| Parameter | Impervious Steep | Impervious Flat | Pervious Small | Pervious Medium | Pervious Large |
|---|---|---|---|---|---|
| Area fraction (-) | 0 | 0.4 | 0 | 0 | 0.6 |
| Wetting (m) | 5.00E-5 | 5.00E-5 | 5.00E-5 | 5.00E-5 | 5.00E-5 |
| Storage (m) | - | 6.00E-4 | 1.00E-3 | 1.00E-3 | 2.00E-3 |
| Start inf. rate (m/s) | - | - | 8.00E-7 | 8.00E-7 | 2.00E-5 |
| End inf. rate (m/s) | - | - | 8.00E-7 | 8.00E-7 | 3.00E-6 |
| Wet exponent (s-1) | - | - | 0 | 0 | 1.50E-3 |
| Dry exponent (s-1) | - | - | 0 | 0 | 3.00E-5 |
| Manning (m1/3s-1) | 80 | 70 | 30 | 30 | 12 |