Terrain decides where water goes, what a foundation costs, how steep an access road gets, and how much dirt has to move before anything gets built. No one breaks ground without a proper land survey, but sending a field crew to land nobody has read yet spends budget answering questions you could have answered from your desk. Remote analysis does not replace the survey. It tells you what the ground is doing early enough to shape the survey scope, the preliminary footprint, the grading budget, and the questions you take to the field.
Four new terrain analysis tools are now live in Google Earth web: elevation contours, slope, aspect, and cut and fill. Each one works the same way. Draw a polygon around your site, set your parameters, and read the result on 3D imagery.
These tools are available on all Google Earth plans. Standard allows you to generate one layer with a tool each month. Professional plans include expanded access and capabilities when you need more tools, a larger site, or both. Each tool answers a different question about the same ground: how it rises and falls, how steep it is, which way it faces, and how much of it has to move. For a full tutorial on how to use tools for work, check out our new video!
Elevation contours: See how the ground rises and falls
Reading elevation across a site has traditionally meant settling for coarse global datasets or tracking down a local survey. The elevation contours tool adds granular detail at 1m intervals across your site in Google Earth with just a few clicks.
Tips for using elevation contours:
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Read the spacing before the numbers. Tightly clustered lines mean rapid elevation change: a steep bank or a sudden drop. Widely spaced lines mean flat, buildable ground.
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Filter to a target elevation band. In the inspector panel, filter your contour layer by elevation value. Isolating the land that sits inside a specific window simplifies terrace planning and flood-clearance checks, or informs agriculture decisions.
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Tune the opacity on every layer you generate. The opacity slider in the inspector panel blends any analysis layer over 3D imagery, so access roads, tree cover, rock outcrops, and property lines stay visible underneath your results. This applies to slope, aspect, and cut and fill just as much as to contours.
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Use elevation profile for linear routes. Contours map topography across an entire polygon. Google Earth's elevation profile tool handles the other case: draw a path along a proposed access road, utility trench, or pipeline, and a profile opens in the inspector with exact elevation gain and loss.
Slope: Find the grades that drive up cost
Slope drives more early-stage cost than perhaps any other terrain factor. Steep ground means more earthwork, retaining structures, and stormwater mitigation, and those costs compound.
Google Earth's slope tool generates a layer across your polygon, color-coded by steepness, at resolutions down to 1 meter.
Tips for using slope:
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Check the 5 to 10 degree band first. Commercial foundations, surface parking, and light industrial pads are commonly sited on ground that stays predominantly within 5 to 10 degrees. Land in this band keeps earthwork modest and accommodates standard slab-on-grade construction.
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Treat 15 degrees as the line where the conversation changes. Ground above 15 degrees, and especially anything approaching 30, generally calls for specialized foundation engineering, runs into municipal grading restrictions, and carries other potential risks such as erosion.
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Look at where the steep zones sit, not just how much there is. Twenty percent steep ground concentrated along one boundary is a different project from the same twenty percent scattered through the middle of your buildable area.
Using Google Earth, Alex Cuellar Díaz, a geotechnical civil engineer in Colombia, used slope alongside elevation contours and land cover to assess 45 square kilometers of rugged terrain after three landslides along critical access roads suspended operations. In Google Earth, he narrowed fieldwork to the high-risk zones covering 7% of the total area.
By combining Google Earth's imagery, data, and tools with my own data, we could select our sites strategically and target field visits strictly to where they were needed. Google Earth allowed me to analyze my site, understand terrain, and tell a clear story with my findings.Geotechnical Civil Engineer
Aspect: Read sun exposure and microclimate from slope direction
Topography interacts directly with solar radiation and local wind. Google Earth's aspect tool calculates the compass orientation of sloping terrain: the exact direction each piece of land faces.
|
Region |
What to look for |
|---|---|
|
Northern Hemisphere |
South-facing slopes (135°–225°) catch low-angle winter sun and avoid the west-facing afternoon heat gain that drives summer cooling loads. |
|
Southern Hemisphere |
North-facing slopes (315°–045°) capture the most solar energy year-round and give crops the best growing conditions. |
Cut and fill: Calculate how much land has to move
Moving dirt is expensive. Every cubic meter trucked off-site (cut) or purchased and hauled in (fill) adds cost to site preparation. Google Earth's cut and fill tool calculates those volumes directly on your site polygon, so you can test grading scenarios before a survey or surface model exists.
The tool runs in two modes:
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Auto-generated optimal elevation. Google Earth calculates the target elevation plane where cut volume matches fill volume. A near-zero net volume means the dirt stays on site, which is the cheapest outcome available.
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Custom target elevation. When the design is already fixed by a finished floor elevation or a tie-in to an existing road grade, enter that value. The tool returns the exact cut and fill volumes required to reach that plane and maps where each one falls across the site.
Start with the auto-generated optimal elevation to find the site's natural balancing point. Then enter custom elevations to price each specific design decision against the earthwork it costs.
Earthwork is one of the largest line items in a site preparation bid, and a bad volume estimate comes straight out of the margin. JR Madrid, President of Custom Scapes, prices commercial work from his desk rather than driving out to measure it.
Google Earth helps us save time and win project bids because we don't need to be on-site to build an accurate quote. Combining imagery with site assessment tools allows us to move faster, better serve our customers, and remotely assess sites for field work at large commercial properties.President of Custom Scapes
Put a tool to work on your next site
Take the site on your desk with the most unknowns and run the one tool that answers your biggest question about it. Contours if you cannot picture the shape of the ground. Slope if the cost is in the grading. Aspect if the sun matters. Cut and fill if you already know the pad and need the volume.
Professional plans include expanded access and capabilities when you need more tools, a larger site, or both.
