Drones are best used for Scottish hillside vegetation surveys by employing high-resolution RGB cameras combined with LiDAR, flying with terrain-following technology to manage steep, complex slopes
. They provide rapid, non-intrusive habitat mapping, enabling detailed, large-scale vegetation classification (e.g., NVC, UKHab) when ground-truthed by ecologists, though they are not a complete substitute for traditional NVC, which requires in-depth ground species identification.
Best Practices for Drone Vegetation Surveys
Sensor Selection: Utilize both high-resolution photogrammetry (RGB) for visual identification and LiDAR for penetrating dense vegetation to map terrain accurately, essential for varied terrain like Scottish hillsides.
Terrain Following: Use UAVs equipped with terrain-following sensors to maintain a constant, optimal altitude (e.g., 50-80m) relative to the changing slope, ensuring consistent ground sample distance (GSD).
Timing: Schedule flights during optimal seasonal windows (e.g., growing season) and in suitable, low-wind weather conditions.
Data Validation (Ground Truthing): Pair the drone imagery with on-the-ground botanical surveys. This ensures that the classified habitat types (e.g., heather moorland, blanket bog) are accurate and that species-level details missed by the drone can be documented.
Safety & Compliance: Adhere to local regulations regarding flying over people and in protected areas (e.g., SSSIs), keeping in mind potential wildlife disturbance.
Drone Survey vs. NVC Survey Equivalence
A drone survey is not fully equivalent to a traditional National Vegetation Classification (NVC) survey, but rather a powerful, highly complementary tool.
What Drone Surveys Do Better: Cover vast, inaccessible, and hazardous terrain in hours, creating accurate 3D models and high-resolution habitat maps.
What NVC Surveys Do Better: Identify fine-scale, cryptic species, assess small-scale patchiness, determine precise species frequencies, and identify rare species obscured under tall vegetation.
Conclusion: The best approach is a hybrid model where drones define the overall habitat composition and structure (vegetation mapping), and ecologists conduct targeted ground checks (NVC) to confirm community classifications
For a vegetation survey of a Scottish hillside, drones are best used as a
complementary tool to enhance speed and access rather than a total replacement for ground-based fieldwork.
Best Use of Drones on Scottish Hillsides
Terrain Navigation: Drones easily cover steep, boggy, or hazardous areas that are difficult or unsafe for surveyors on foot.
Sensor Selection:
RGB Cameras: Best for high-resolution Orthomosaic Maps used to identify broad habitat types (Phase 1 or UKHab) and visible features like erosion gullies or bare peat.
Multispectral Sensors: Essential for calculating indices like NDVI, which detect vegetation stress, health, and subtle species differences (e.g., distinguishing between vigorous and declining heather).
LiDAR: Crucial for penetrating thick canopy or tall vegetation (like bracken or gorse) to reveal underlying topography or structural layers.
Invasive Species Mapping: Highly effective for rapidly mapping the spread of Rhododendron or bracken across large areas.
Repeatability: Flight paths can be automated to ensure identical coverage for long-term monitoring of restoration progress.
Drone vs. NVC (National Vegetation Classification) Survey
A drone survey is not equivalent to a standard NVC survey, though it can be highly integrated into one.
Feature
Identification
Drone survey
Excellent for broad patterns and dominant species; struggles with rare or small plants.
Traditional NVC Survey
Precise species-level identification, including mosses, liverworts, and hidden grasses.
Efficiency
Drone survey
Can cover hundreds of acres in a single day.
Traditional NVC Survey
Time-intensive; limited by human walking speed and daylight.
Output
Drone survey
High-resolution spatial maps and 3D terrain models.
Traditional NVC Survey
Qualitative descriptions and manual polygon mapping.
Requirement
Can suggest NVC communities but requires "ground-truthing".
Traditional NVC Survey
The gold standard for legal and planning compliance in Scotland.
Practical Integration:
Current best practice in Scotland (e.g., by Geckoella or NatureScot) uses drones to map the "shape" of habitats and then sends an ecologist to specific, representative points to confirm the exact NVC community