# Catchment Area (Recursive)

O.Conrad (c) 2001
Recursive upward processing of cells for calculation of flow accumulation and related parameters. This set of algorithms processes recursively all upwards connected cells until each cell of the DEM has been processed.
References:
Deterministic 8
- O'Callaghan, J.F. / Mark, D.M. (1984):
'The extraction of drainage networks from digital elevation data',
Computer Vision, Graphics and Image Processing, 28:323-344
Rho 8:
- Fairfield, J. / Leymarie, P. (1991):
'Drainage networks from grid digital elevation models',
Water Resources Research, 27:709-717
Deterministic Infinity:
- Tarboton, D.G. (1997):
'A new method for the determination of flow directions and upslope areas in grid digital elevation models',
Water Ressources Research, Vol.33, No.2, p.309-319
Multiple Flow Direction:
- Freeman, G.T. (1991):
'Calculating catchment area with divergent flow based on a regular grid',
Computers and Geosciences, 17:413-22
- 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

## Parameters

Grid system
Grid system
  Grid system
Elevation
Input Grid
Sink Routes
Input Grid
Weight
Input Grid
Material
Input Grid
Target
Input Grid
Catchment Area
Output Grid
Catchment Height
Output Grid
Catchment Slope
Output Grid
Total accumulated Material
Output Grid
Accumulated Material from _left_ side
Output Grid
Accumulated Material from _right_ side
Output Grid
Step
Integer
  Minimum: 1.0
Target Areas
Input Grid
Flow Path Length
Output Grid
Method
Choice
  Available choices: Deterministic 8, Rho 8, Deterministic Infinity, Multiple Flow Direction
Convergence
Floating point
  Convergence factor for Multiple Flow Direction Algorithm (Freeman 1991)