# 07: Extended neighbourhoods - catchment areas (trace flow)

Copyrights (c) 2003 by Olaf Conrad
Extended Neighbourhoods - Catchment areas.
(c) 2003 by Olaf Conrad, Goettingen
email: oconrad@gwdg.de

## Parameters

Grid system
Grid system
  Grid system
Elevation grid
Input Grid
  This must be your input data of type grid.
Catchment area
Output Grid
  This will contain your output data of type grid.
Flow Path Length
Output Grid
  This will contain your output data of type grid.
Step
Integer
  Skip cells (step value).
  Minimum: 1.0
Method
Choice
  Choose a method
  Available choices: Needs less memory, but is slow, Needs more memory, but is quicker
Single Cell
Boolean
  Set 'false' to execute the calculation for each point in grid. Set 'true' tu calculate the flow of one single cell.
X Position
Integer
Y Position
Integer