Creating an elevation profile: reading terrain along a route
An elevation profile shows how a line behaves on the ground, not just how long it is on the map. For roads, pipelines, drainage and access routes, slope can matter more than horizontal distance.
Field takeaways
- A profile reads distance and elevation together.
- Grade may be expressed as percent, per mille or degrees; state the unit.
- DEM profiles help planning; precise work needs surveyed elevations.
- Vertical exaggeration improves readability but can visually overstate slopes.
- Point spacing determines how well the profile captures the ground.
What a profile shows
Two points can be 500 metres apart on the map — and if there is 40 metres of elevation change between them, the cost, the safety and the method of the job all change. An elevation profile shows the level at every distance along the line, so ramps, dips and breaks reveal themselves in one glance.
Grade, and its units
Grade is the elevation difference divided by the horizontal distance: rising 5 metres over 100 metres is a 5 percent grade. Road, pipe and drainage work sometimes uses per mille instead. State the unit in the report — 5 percent and 5 per mille are very different slopes, and the reader cannot guess which you meant.
DEM profile or surveyed levels?
A DEM-based profile is fast and excellent for route planning. Precise site levels — culvert inverts, road platforms, drainage gradients — need levels measured in the field. GNSS vertical accuracy is generally weaker than horizontal, so control points, levelling or total station support may be required where the level gets built.
Vertical exaggeration and false impressions
Stretching the vertical axis makes detail readable, and it also makes the terrain look steeper than it is. If the reader of the report is not technical, say the profile is vertically exaggerated — otherwise a decision-maker can mistake a mild slope for a serious problem.
Using it in MapLab Survey
Draw or import the line, take the profile, and note the critical grade sections. When the route goes to CAD/GIS, send the profile notes with the report. A profile is not just a nice graphic — it is the trace of the decision made in the field.
See it in action
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Frequently asked questions
What is an elevation profile for?
It shows elevation change, grade and breaks along a route.
Is a DEM profile enough?
Good for planning; precise work needs field survey elevations.
Percent or per mille?
Use the project standard and state the unit clearly.
Is vertical exaggeration a problem?
It can mislead non-technical readers if not stated.
Technical references
The field guidance in this article is aligned with the technical and official references below.
Related: Cut-and-fill calculation · RTK GNSS field accuracy · Exporting field data to CAD/GIS · MapLab Survey