Fill Minima

Author(s)	Justus Spitzmüller (c) 2025, Neil Flood (c) 2015, Richard Barnes (c) 2014
Library ID	ta_preprocessor
Tool ID	8
Version	2.0
Menu	Terrain Analysis \| Preprocessing

Description

This tool performs basic sink filling on Digital Elevation Models (DEMs). It identifies and fills local depressions (sinks) to ensure continuous flow paths across the terrain surface. Note: this tool does not carry out a full hydrological correction â€“ it only addresses depressions and does not modify flat areas, resolve flow directions, or enforce hydrological consistency beyond sink removal. The tool accepts a DEM as input and returns a version with filled depressions. Optionally, users can define a fixed boundary value to control how edge/boundary cells are initialized during filling. Recommended Usage:

Choose Soille & Gratin for (scaled) integer DEMs.
Choose Barnes et al. for floating-point DEMs.

References

Python Fmask

RichDEM

Barnes, R., Lehman, C., & Mulla, D. (2014): Priority-flood: An optimal depression-filling and watershed-labeling algorithm for digital elevation models. Computers & Geosciences, 62, 117-127.

Soille, P., & C. Gratin (1994): An efficient algorithm for drainage network extraction on DEMs. . Journal of Visual Communication and Image Representation. 5(2): 181-189.

Parameters

	Name	Type	Identifier	Description	Constraints
Input	DEM	grid, input	`DEM`	Digital Elevation Model	-
Output	Filled DEM	grid, output	`RESULT`	Processed DEM	-
Options	Grid System	grid system	`PARAMETERS_GRID_SYSTEM`	-	-
	Method	choice	`METHOD`	-	Available Choices: [0] Auto detection by input [1] Soille & Gratin 1994 [2] Barnes et al. 2014 Default: 0
	Set Fixed Boundary Value	boolean	`BOUNDARY`	-	Default: 0
	Boundary Value	floating point number	`BOUNDARY_VALUE`	The boundary value will be scaled by the scaling factor of the input.	Default: 1.000000

Command Line


Usage: saga_cmd ta_preprocessor 8 [-DEM ] [-RESULT ] [-METHOD ] [-BOUNDARY ] [-BOUNDARY_VALUE ]
  -DEM:                 DEM
	grid, input
  -RESULT:              Filled DEM
	grid, output
  -METHOD:
                             Method
                             	choice
                             	Available Choices:
                             	[0] Auto detection by input
                             	[1] Soille & Gratin 1994
                             	[2] Barnes et al. 2014
                             	Default: 0
  -BOUNDARY:            Set Fixed Boundary Value
	boolean
	Default: 0
  -BOUNDARY_VALUE:   Boundary Value
	floating point number
	Default: 1.000000