Understanding how easy (or difficult) it is to move through a forest stand is something every forester and contractor experiences — but until recently, it has been difficult to quantify at scale.
Using LiDAR data, Interpine has developed an approach to map human walk hindrance, providing a new way to visualise and measure vegetation density that directly impacts operational productivity, safety, and cost.
Why Walk Hindrance Matters
In operational forestry, dense understorey vegetation can significantly affect:
- Productivity – Slowing movement for survey crews and contractors
- Health and safety – Increasing fatigue, trip hazards, and limited visibility
- Operational costs – Driving variability in thinning, pruning, and harvesting effort
While experienced operators understand these challenges intuitively, they are rarely quantified consistently across a forest estate. This is where LiDAR provides a powerful opportunity.
Turning LiDAR into a Walk Hindrance Layer
LiDAR point clouds capture detailed 3D information about forest structure, including vegetation at different heights. Interpine’s approach focuses specifically on vegetation density at heights that directly affect human movement.
This height range represents the zone where vegetation becomes a physical barrier to movement, either by humans or machines, including:
- Exotic or native shrubs and regenerating vegetation
- Ferns and ground cover
- Down trees / branches
- Low branches and dense young stands
By analysing LiDAR return density within this band, we can derive a relative hindrance score across the landscape. Interpine’s relative hindrance score has been incorporated in TreeTools Silva Cloud LiDAR Analysis workflow. You can simply upload your LiDAR datasets and access the provided hindrance maps. Interpine can also provide this as a custom service for large areas across full estates or landscape level.
From Point Clouds to Practical Maps
The process converts complex 3D LiDAR data into a simple, interpretable hindrance surface, typically classified into categories such as:
- None / low hindrance – Open, easy movement
- Medium hindrance – Minor obstruction
- Heavy hindrance – Noticeable impact on movement
- Extreme hindrance – Dense vegetation significantly restricting access
These outputs can then be visualised at:
- Stand level
- Operational block level
- forest estate scale
- Landscape level
The resulting maps provide an immediately intuitive view of where movement is easy — and where it becomes slow, difficult, or hazardous.
Validating Against Real-World Conditions
Initial validation compares LiDAR-derived hindrance maps against on-the-ground observations of vegetation density and walkability.
Here are some example of how the Hindrance Index compares to on ground imagery. Areas classified as low hindrance aligning with open, easily traversed stands, areas classified as high hindrance corresponding to dense fern, blackberry, scrub, or regeneration
This alignment demonstrates how LiDAR can reliably capture the conditions that field crews experience every day.
Practical Benefits for Forestry Operations
1. Smarter Planning and Deployment
Walk hindrance mapping enables better planning of:
- Survey routes
- Crew allocation
- Time expectations for field work
2. Improved Health and Safety Outcomes
By identifying areas of heavy hindrance in advance, teams can:
- Plan safer access routes
- Reduce fatigue and exposure to hazards
- Prepare for challenging terrain conditions
3. Cost Transparency for Contractors / Survey Crews
For survey crews / silvicultural contractors, this is particularly powerful.
Operations such as:
- Thinning
- Pruning
- Release spraying
- Harvesting
- Forest Inventory
- Native Forest Survey and Monitoring
are all impacted by how easy it is to move through a stand.
With hindrance mapping:
- Contractors can quantify operational difficulty
- Forest managers can better understand cost variability
- Pricing can more accurately reflect true site conditions
From Insight to Decision Support
Beyond mapping, the concept can be extended to:
- Ranking stands by hindrance level
- Generating a hindrance score per stand to support planning and valuation
- Integrating into broader forest inventory and GIS workflows
This creates a consistent, repeatable way to incorporate ground accessibility into decision-making — something that has traditionally been subjective.
Bringing Innovation to Operational Forestry
LiDAR has long been used to measure trees — but its value extends well beyond inventory.
By deriving walk hindrance directly from vegetation structure, Interpine is helping transform how forestry operations:
- Plan work
- Manage risk
- Understand cost
- Optimise productivity
This is another step toward fully data-driven forest operations, where decisions are informed not just by what is growing — but by how the forest can actually be worked.