4.1.1 Analytic Hierarchy Process (AHP)

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Fig. 4.1 AHP Widget - input tab

Run Analytic Hierarchy Process (AHP) analysis.

4.1.1.1 Usage

  1. Add rasters to the calculation with a dialog (7)

  2. Provide an name for the output files (9)

  3. Select a method to derive the priority vector (10)

  4. Move to the raster value comparison tab (4) or click next (2).

Remove raster datasets from the calculation by clicking (8)

Raster tabs (4):

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Fig. 4.2 AHP Widget - raster tab

  1. Assign a rating to each pairwise raster value comparison (6)

  2. Continue to the pairwise raster comparison tab (5)

Pairwise raster comparison tab (5):

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Fig. 4.3 AHP - pairwise raster comparison tab

  1. Assign a rating to each pairwise raster comparison (6)

  2. Return to the input tab and click Apply (11)

After the calculation finished you can view the results (2) by right clicking the output .npz in the catalog.

4.1.1.2 Information

Scale of preference (Saaty, 1977)

Intensity of importance

Definition

Explanation

1

Equal importance

Two activities contribute equally to the objective

3

Weak importance of over another

Experience and judgment slightly favor one over another

5

Essential or strong importance

Experience and judgment strongly favor one over another

7

Demonstrated importance

One is strongly favored and its dominance is demonstrated in practice

9

Absolute importance

The evidence favoring one over another is of the highest possible order of affirmation

2, 4, 6, 8

Intermediate values

Compromises

Reciprocals

Inverse comparison

Inverse comparison

You can write number < 1 as fractions in the pairwise comparison table, e.g. “1/7” get converted to 0.14285714286.

LSAT supports AHP for raster datasets with up to 10 values. If you have a continuous raster or a raster dataset with more unique values reclassify them first with the Sensitivity Reclassification Widget or Reclassify Widget.

4.1.1.3 Input and Output

Input

Raster dataset(s) (.tif)

Output

AHP model raster dataset (.tif)

Output path: /results/AHP/rasters/*output name*.tif

AHP model information (.npz)

Output path: /results/AHP/tables/*output name*_tab.npz