Maps

Hillshade / shaded-relief map

Uses terrain slope, aspect and a light model to reveal landform shape.

Map
Geography
Terrain

What it answers

What terrain forms are present?

Shape: Raster with simulated illumination
What it shows: Ridges, valleys, slopes and relief.

Example

The question

Where are the hills and valleys around our new site?

Terrain around the planned warehouse (shaded relief)

Grey shading lit from the north-west makes hills stand out: two larger hills west and south-east of the planned site, which sits in a flat valley between them.

Illustrative data. It belongs to no company.

When to use it

Use it when

Making terrain shape legible.

Avoid it when

Interpreting brightness as a direct elevation measure.

How to read it

Read shading as simulated illumination, with elevation context if supplied.

Note

Brightness is not a direct elevation scale.

The data you need

Layout: Raster plus geospatial metadata
Fields: Georeferenced elevation raster: cell elevations, CRS, resolution and no-data mask
One row is: One cell in a digital elevation model. What is the grain?
Rules: Use a georeferenced elevation raster. Specify sun azimuth, altitude, vertical units and any vertical exaggeration.
Optional: A CSV alone is insufficient unless converted into a correctly georeferenced grid.
Preparation: Prepare a georeferenced elevation raster with correct horizontal/vertical units; compute illumination from a stated light model.
Units: Input elevation hasvertical units; output shading isillumination intensity, not elevation.

An attribute table joined to map shapes by a shared region code.

Worked example

The same hill shaded with light from northwest hasdifferent bright slopes than with light from southeast. Terrain height itself has not changed.

Raster metadata: CRS	CellSize	ElevationUnit
projected CRS	10 metres	metres
Raster cells: elevations on a regular grid

All charts in the library