# SIBERIA: Channel Module Parameters

The parameters controlling the channel-gully development module

SIBERIA parameter number | SIBERIA parameter name | Dialog Descriptor | Explanation
13 | ModeCh | Mode for channel model | Channel geometry model selected ModeCh=0: default model, geometry of the channel not calculated ModeCh=1: depth calculated as a function of area
#### Channel Initiation Function:
27 | 1/at | CIF threshold | The threshold which if exceeded means a hillslope becomes a channel
44 | b5 | Coefficent on the channel initiation function (CIF) relationship | This is the coefficient of the process that triggers channel formation. e.g. if the process considered is shear stress then this is a function of mannings n.
47 | m5 | Exponent on the discharge in the CIF relationship | This is the exponent on discharge in the process that triggers channel/gully formation. e.g. if this process is bottom shear stress then a value of 0.3 is appropriate.
45 | n5 | Exponent on the slope in the CIF relationship | This is the exponent on slope in the process that triggers channel/gully formation. e.g. if this process is bottom shear stress then a value of 0.4 is appropriate.
36 | a1 | Discharge factor between fluvial transport and CIF | This factor multiplies the discharge used in the sediment transport equation to yield the discharge used in the channel model Unless there is a strong case otherwise this parameter is generally a1=1
52 | dtime | Rate of channel formation | This parameter determines the rate at which a channel is formed once the CIF threshold is exceeded. A large value gives fast forming channels/gullies, while a low value yields slow forming channels/gullies
#### Channel Geometry Model: This model is only active if ModeCh=1
57 | b6 | Coefficent on the channel geometry model | If this parameter is larger then gullies are deeper for a given catchment area.
58 | m6 | Exponent on area in the channel geometry model | If this parameter is larger then the gullies get deeper more quickly as you proceed downstream.