Threshold Buffer

Author: Victor Olaya (c) 2004
Menu: Grid | Distances

Description

This tool performs a feature-buffering operation on a raster layer with additional constraint logic based on a secondary raster input. Unlike standard buffers, it dynamically extends the buffer zone by evaluating each neighboring cell against a user-defined threshold. The extension is conditionally applied based on the values in the secondary raster and can operate in two modes: - Absolute: compares each neighboring cell's value in the secondary raster directly to the threshold. - Relative to start cell value: compares each neighboring cell's value relative to the starting cell's value. Buffer expansion occurs only if the increase or change is within the threshold, allowing for value-sensitive spatial analysis, such as terrain-aware or cost-constrained buffering.

Parameters

	Name	Type	Identifier	Description	Constraints
Input	Features	grid, input	`FEATURES`	Input grid with the features to buffer where valid grid cells are all non-zero, non-NoData values. Cells with a value of 0 or NoData are ignored.	-
	Value	grid, input	`VALUE`	Secondary input grid with the values used to evaluate the threshold value.	-
	Threshold	grid, input, optional	`THRESHOLDGRID`	Optional input grid with spatially variable threshold values.	-
Output	Buffer	grid, output	`BUFFER`	The buffered output grid. Input features are labelled by 2, buffer zones by 1 and all other cells with 0.	-
Options	Grid System	grid system	`PARAMETERS_GRID_SYSTEM`	-	-
	Threshold Value	floating point number	`THRESHOLD`	The threshold value to apply. Expansion occurs only if the increase or change is within the threshold.	Default: 0.000000
	Threshold Type	choice	`THRESHOLDTYPE`	The mode of operation.	Available Choices: [0] Absolute [1] Relative (to start cell value) Default: 0

Command Line


Usage: saga_cmd grid_tools 9 [-FEATURES ] [-VALUE ] [-THRESHOLDGRID ] [-BUFFER ] [-THRESHOLD ] [-THRESHOLDTYPE ]
  -FEATURES:        Features
	grid, input
  -VALUE:           Value
	grid, input
  -THRESHOLDGRID:   Threshold
	grid, input, optional
  -BUFFER:          Buffer
	grid, output
  -THRESHOLD:    Threshold Value
	floating point number
	Default: 0.000000
  -THRESHOLDTYPE:
                         Threshold Type
                         	choice
                         	Available Choices:
                         	[0] Absolute
                         	[1] Relative (to start cell value)
                         	Default: 0