I would like to calculate TWI using different flow routing methods. I calculated the catchment area using different method. In the module for calculating TWI, it asks whether the catchment area is specific catchment area or pseduo catchment area. Is there a way in SAGA to calculate specific catchment area or using the pseudo conversion will suffice.
Thank you.
If you would like to refer to this comment somewhere else in this project, copy and paste the following link:
In case you don't like to use the "1 / cell size (pseudo specific catchment area)" method, you can use the "Flow Width and Specific Catchment Area" module to convert your catchment grids beforehand. The module provides three calculation methods:
Deterministic 8
Multiple Flow Direction (Quinn et al. 1991)
Aspect
Best regards,
Volker
If you would like to refer to this comment somewhere else in this project, copy and paste the following link:
Under the MFD option within Specific Catchment Area, are the same default used as provided in the Catchment area (Parallel) module? (i.e. Linear flow = false, Convergence = 1.1, etc.)
If you would like to refer to this comment somewhere else in this project, copy and paste the following link:
...no! this tool just follows the approach of quinn et al. (1991) to define a flow width based on their multiple flow direction concept.
Quinn, P.F., Beven, K.J., Chevallier, P., Planchon, O. (1991): The prediction of hillslope flow paths for distributed hydrological modelling using digital terrain models. Hydrological Processes, 5:59-79.
If you would like to refer to this comment somewhere else in this project, copy and paste the following link:
Hi Everyone,
I would like to calculate TWI using different flow routing methods. I calculated the catchment area using different method. In the module for calculating TWI, it asks whether the catchment area is specific catchment area or pseduo catchment area. Is there a way in SAGA to calculate specific catchment area or using the pseudo conversion will suffice.
Thank you.
In case you don't like to use the "1 / cell size (pseudo specific catchment area)" method, you can use the "Flow Width and Specific Catchment Area" module to convert your catchment grids beforehand. The module provides three calculation methods:
Best regards,
Volker
Under the MFD option within Specific Catchment Area, are the same default used as provided in the Catchment area (Parallel) module? (i.e. Linear flow = false, Convergence = 1.1, etc.)
...no! this tool just follows the approach of quinn et al. (1991) to define a flow width based on their multiple flow direction concept.
Quinn, P.F., Beven, K.J., Chevallier, P., Planchon, O. (1991): The prediction of hillslope flow paths for distributed hydrological modelling using digital terrain models. Hydrological Processes, 5:59-79.