Tool Flow Width and Specific Catchment Area
Flow width and specific catchment area (SCA) calculation. SCA calculation needs total catchment area (TCA) as input, which can be calculated with one of the flow accumulation tools. 
References
- Gruber, S., Peckham, S. (2008): Land-Surface Parameters and Objects in Hydrology. In: Hengl, T. and Reuter, H.I. [Eds.]: Geomorphometry: Concepts, Software, Applications. Developments in Soil Science, Elsevier, 33:293-308. https://www.elsevier.com/books/geomorphometry/hengl/978-0-12-374345-9.
 - 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 http://onlinelibrary.wiley.com/doi/10.1002/hyp.3360050106/full.
 
- Author: O.Conrad (c) 2009
 
- Menu: Terrain Analysis|Hydrology|Flow Accumulation
 
Parameters
|   | Name | Type | Identifier | Description | Constraints | 
| Input | Elevation | Grid, input | DEM | - | - | 
 | Total Catchment Area (TCA) (*) | Grid, input, optional | TCA | - | - | 
| Output | Flow Width | Grid, output | WIDTH | - | - | 
 | Specific Catchment Area (SCA) | Grid, output | SCA | - | - | 
| Options | Grid System | Grid system | PARAMETERS_GRID_SYSTEM | - | - | 
 | Method | Choice | METHOD | - | Available Choices: [0] Deterministic 8 [1] Multiple Flow Direction (Quinn et al. 1991) [2] Aspect Default: 2 | 
| (*) optional | 
Command-line
Usage: saga_cmd ta_hydrology 19 [-DEM <str>] [-WIDTH <str>] [-TCA <str>] [-SCA <str>] [-METHOD <str>]
  -DEM:<str>   	Elevation
	Grid, input
  -WIDTH:<str> 	Flow Width
	Grid, output
  -TCA:<str>   	Total Catchment Area (TCA)
	Grid, input, optional
  -SCA:<str>   	Specific Catchment Area (SCA)
	Grid, output
  -METHOD:<str>	Method
	Choice
	Available Choices:
	[0] Deterministic 8
	[1] Multiple Flow Direction (Quinn et al. 1991)
	[2] Aspect
	Default: 2