GIS Layer Overlay: Site Suitability Analysis

Map view

Analysis weights

Flat land 0.40

Road access 0.35

Low population 0.25

Territory

Terrain roughness 0.50

Mean suitability

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Best site score

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High-suitability area

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Cells analysed

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How it works

A GIS answers "where is the best place?" by stacking independent raster layers of the same territory and combining them cell-by-cell — this is weighted overlay analysis. Here the territory is a grid of cells, each carrying three measured values: elevation-derived slope (flatness), distance to the nearest road, and modelled population density. Every cell's suitability is a weighted average of how well it scores on each criterion; the gold marker tracks whichever cell currently scores highest.

score(cell) = Σ wᵢ · criterionᵢ(cell) / Σ wᵢ
flatness  = 1 − slope / max(slope)
access    = 1 − distanceToRoad / range
low-pop   = 1 − popDensity(cell)

Flat land / Road access / Low population — the weight each criterion contributes to the combined score; push one to zero to see the map recompute around the remaining criteria only.
Terrain roughness — regenerates the elevation layer with a new relief amplitude; steeper relief makes flatness a much sharper filter.
Elevation / Suitability — switch the base map between raw terrain colour and the live weighted-overlay result.
Roads / Population — toggle each source layer's own 3D rendering on and off independently of whether it still feeds the analysis.

Real-world relevance: this is the same operation behind siting a new clinic, warehouse or cell tower — planners rarely have one perfect layer, so they overlay several imperfect ones and let the weights encode their priorities.

Low elevation High elevation Low suitability High suitability Best site

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