Choosing a suitable location for a road, building, water facility, development project, agricultural activity, or other infrastructure often begins with a preliminary site selection process. Before visiting every possible location, Google Earth Pro can help you visually screen candidate sites and identify important characteristics that require further investigation.
Google Earth Pro provides tools for viewing terrain, measuring distances and areas, examining historical imagery, viewing available 3D buildings, and exploring locations from ground level.
It is important to understand that this is a screening method, not a replacement for professional surveying, geotechnical investigation, environmental assessment, or detailed engineering design.
What Is Preliminary Site Selection?
Preliminary site selection is the process of identifying potentially suitable locations before detailed investigation begins.
The objective is not necessarily to prove that a site is suitable. Instead, the process helps answer questions such as:
- Is the site accessible?
- What is the surrounding land use?
- Is the terrain relatively suitable?
- Are there nearby roads or settlements?
- Are there obvious physical constraints?
- Has the area changed significantly over time?
- Which candidate sites deserve detailed field investigation?
Google Earth Pro is particularly useful during this early screening stage because you can examine several locations without immediately visiting each one.
For detailed surveying applications, see How to Use Google Earth Pro for Land Surveying and Site Analysis.
Step 1: Define Your Site Selection Requirements
Start by deciding what makes a location suitable for your project.
For example, a preliminary screening for a proposed facility might consider:
| Factor | What to examine |
|---|---|
| Accessibility | Roads and nearby routes |
| Terrain | Slopes, hills and valleys |
| Elevation | Relative elevation of candidate sites |
| Land use | Buildings, vegetation and developed areas |
| Surroundings | Nearby settlements and infrastructure |
| Historical change | Previous land-use conditions |
| Space | Approximate available area |
| Constraints | Rivers, steep terrain or dense development |
The factors should match the type of project. A potential water facility, residential development, road alignment, and agricultural site will not have identical requirements.
Step 2: Identify Several Candidate Sites
Do not immediately select the first location that looks suitable.
Search the wider study area and identify several potential sites. Create a placemark for each candidate and give them clear names such as:
- Candidate Site A
- Candidate Site B
- Candidate Site C
You can then compare them using the same criteria.
Google Earth Pro also allows you to create paths and polygons to mark routes and areas of interest.
A simple candidate-site map can make the screening process much easier to document and review.
Step 3: Examine Terrain and Elevation
Terrain can strongly influence the feasibility and cost of many projects.
Turn on the Terrain layer and examine the surrounding landscape. Look for steep slopes, ridges, valleys, low-lying areas and relatively level ground.
You can also draw a path through or near a candidate site and use the elevation profile to examine changes in elevation along that path. Google Earth Pro displays elevation against distance and allows you to inspect different points along the profile.
For example, if two potential locations are being considered for a proposed facility, the terrain view may reveal that one site is on considerably steeper ground than the other.
However, Google Earth elevation information should be treated as preliminary information, not as a substitute for a detailed topographic survey.
Step 4: Check Access and Surrounding Infrastructure
Examine the roads and routes surrounding each candidate site.
Ask:
- Is there an existing road nearby?
- How far is the site from the nearest major road?
- Is the access route direct or complicated?
- Are there visible buildings or infrastructure nearby?
- Does the surrounding development create potential constraints?
Google Earth Pro's measurement tools can help estimate distances and areas. Google notes that measurements can have limitations, particularly around 3D terrain and buildings, so they should be treated appropriately for the purpose of the assessment.
Step 5: Examine Land Use and Surroundings
Look beyond the candidate site itself.
A location may appear suitable when viewed closely but become less attractive when the surrounding area is considered.
Look for:
- Existing buildings
- Agricultural land
- Vegetation
- Water bodies
- Roads
- Industrial areas
- Residential development
- Other visible infrastructure
The 3D Buildings feature can provide additional context in locations where 3D imagery is available.
This can be particularly useful when screening sites in developed urban or peri-urban areas.
Step 6: Check the Site from Ground Level
Satellite imagery does not always provide enough information about what a location looks like from the ground.
Where Street View coverage is available, drag Pegman onto the appropriate road and examine the surroundings from ground level. Google Earth supports ground-level exploration using Street View imagery.
This can help you identify visible conditions such as road access, nearby structures and the general character of the surrounding area.
However, Street View coverage varies by location and the imagery may not represent current conditions.
Step 7: Compare Historical Imagery
Historical imagery can help determine whether a candidate site or its surroundings have changed.
For example, you might discover that:
- A previously undeveloped area has become built up.
- A road has changed.
- Vegetation has been cleared.
- A water body has changed.
- Development has expanded toward the candidate site.
Google explains that imagery may be assembled from photographs collected over different dates, and the displayed date does not necessarily represent a single capture of the entire visible area.
Therefore, historical imagery is useful for context and change detection, but not as definitive evidence of every historical condition.
Step 8: Create a Simple Candidate-Site Comparison
Once you have examined the locations, create a simple comparison table.
For example:
| Factor | Site A | Site B | Site C |
|---|---|---|---|
| Road access | Good | Moderate | Poor |
| Terrain | Moderate | Steep | Gentle |
| Nearby development | Low | High | Moderate |
| Available space | Good | Moderate | Good |
| Historical change | Low | High | Low |
This does not automatically determine the best site. Instead, it provides a transparent basis for deciding which locations deserve field verification and detailed investigation.
or distance, area, and elevation measurements, see the official Google Earth Help — Measure Distance & Elevation guide. Google Earth Help — Measure Distance & Elevation
Important Limitations
Google Earth Pro should not be used alone to approve a site for construction or other high-consequence decisions.
Satellite imagery, elevation models, 3D imagery and Street View have limitations. Imagery can also represent different collection dates, while 3D imagery is created from aerial imagery collected over multiple dates.
A final site assessment may require:
- Professional topographic surveying
- Geotechnical investigation
- Environmental assessment
- Land ownership and legal checks
- Flood or drainage assessment
- Utility investigations
- Detailed engineering analysis
- Current field verification
Conclusion
Google Earth Pro for site selection is most useful as an early screening tool. By comparing terrain, elevation, access, surrounding land use, historical imagery, 3D features and ground-level views, you can narrow several potential locations down to a smaller group for detailed investigation.
The strongest approach is to use Google Earth Pro to identify and compare candidates, then verify the preferred locations using appropriate field surveys, technical studies and professional data before making a final decision.
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