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.