Parcellation (GWB_PARC)#

This module conducts the Parcellation analysis. It provides a statistical summary file (txt/csv- format) with details for each unique class found in the image as well as the full image content: class value, total number of objects, total area, degree of parcellation. Details on the methodology and input/output options can be found in the Parcellation product sheet.

Requirements#

A single band (Geo)TIFF image in data format byte:

  • 0 byte: missing (optional)

  • at least two different landcover classes

Processing parameter options are stored in the file input/parc-parameters.txt.

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; GWB_PARC parameter file:
;; NOTE: do NOT delete or add any lines in this parameter file!
;;
;; PARC: Landscape Parcellation index
;; Input image requirements: [1b, 255b]-land cover classes,
;;    optional: 0b-missing
;;
;; PARC will provide summary statistics only.
;;
;; Please specify entries at lines 17 ONLY using the following options:
;; line 17: Foreground connectivity: 8 (default) or 4
;;
;; an example parameter file using 8-connected foreground:
;; 8
****************************************************************************
8
****************************************************************************

Example#

The results are stored in the directory output, one directory for each input image accompanied by a log-file providing details on computation time and processing success of each input image.

GWB_PARC command and listing of results in the directory output:

$ GWB_PARC -i=$HOME/input -o=$HOME/output
IDL 9.1.0 (linux x86_64 m64).
(c) 2024, NV5 Geospatial Solutions, Inc.

GWB_PARC using:
dir_input= $HOME/input
dir_output= $HOME/output
% Loaded DLM: TIFF.
Done with: clc3class.tif
Done with: example.tif
Done with: gscinput.tif
PARC finished sucessfully

$ ls -R output/
output/:
clc3class_parc  example_parc  parc.log

output/clc3class_parc:
clc3class_parc.csv  clc3class_parc.txt

output/example_parc:
example_parc.csv  example_parc.txt

Example statistics of the input image clc3class.tif showing statistics and degree of parcellation for each land cover class as well as for the entire image area:

Class   Value      Count     Area[pixels]     APS          AWAPS       AWAPS/data       DIVISION      PARC[%]
    1       1          45       2448931    54420.7000  2076600.0000  1271360.0000        0.1520        1.1937
    2       2         164        957879     5840.7300    82557.6000    19770.0000        0.9138       17.7426
    3       3         212        593190     2798.0700   128177.0000    19008.4000        0.7839       11.0897
================================================================================================================
8-conn. Parcels:      421       4000000     9501.1875                1310139.4429        0.6725        8.0790

Remarks#

  • Parcellation is a normalized summary index in [0, 100]%.

  • GWB_PARC provides a tabular summary only.

Parcellation, or the degree of dissection, may be useful to provide a quick tabular summary for each land cover class as well as for the entire image. Together with the degree of division, it may be used to make a statement on the dissection of a particular land cover class. Because Parcellation is a normalized index, measuring Parcellation can be used to quantify temporal changes over a given site as well as directly compare the degree of parcellation of different sites. Being able to quantify changes in percent may also be useful to investigate if a given landscape planning measure had in fact a tangible influence on a specific land cover type or not.