Objective Evidence – Measuring the Wear

The world around us is constantly changing and always shifting, either due to natural forces, man made intervention, or a combination of the two. Photogrammetry for Trail Erosion Measurement is a powerful tool to monitor environmental change.

Measuring these changes is part of what photogrammetry is best at. We can quickly quantify differences and changes in everything from buildings to quarrying and stockpiles to seabed wrecks and this is part of what we teach in the AccuPixel Metashape Professional course.

Along with 3D digital reconstruction & preservation one of Simon’s other passions is mountain biking. The sport is hugely popular, delivering wild open space physical and mental health benefits to riders. However, like all human activities, it can have negative impacts, one of which is accelerated trail erosion.

Objective Evidence

Mountain biking trails tend to be narrow – just 30cm wide in places – and the knobbly tyres spread the load of rider so overall impact can be light but two recent events have seen a section of local trails see increased erosion:

• COVID lockdowns has seen more riders enjoy and use the lands
• Recent periods of extended, heavy rainfall have saturated the lands

Also, the combination of the two have combined to increase erosion in a few very localised areas. Visually we can see the changes…and intervention may be necessary…but just how much has eroded?

When evaluating the overall trail network, which spans hundreds of kilometers, the impacted areas are statistically insignificant. However, the sport must acknowledge the negative impact and, when necessary, be prepared to undertake restorative work to address the issues.

Many recreational users and landowners are asking these questions. Can photogrammetry provide the answers? Can Photogrammetry for Trail Erosion Measurement be an applicable solution?

A short drone flight gathered the images of the area and whilst the vegetation cover was prolific the trails stood out enough for Metashape Professional to align the images.

Measure the Changes through Photogrammetry

Metashape Professional analysis tools have helped us understand how the trail is today. We can provide anyone who needs to know accurate measurements revealing the current state of the trail as of the 18th August 2021.

The first drone flight and subsequent processing has established a baseline – a digital copy – of the trail.

Objective vs Subjective: Photogrammetry for Trail Erosion Measurement

Measuring mountain biking and its impact on the environment is important and can act as a guide to what and where the issues are. Landowners can be hostile to the mountain biking community but this kind of objective information can either highlight very real concerns, or explain and demonstrate MTB is causing minimal harm.

In 3~6 months we can repeat the flight and gather a second set of images. Then we can build a second model and compare the changes using the two DEMs. This is something we teach in our Agisoft endorsed Metashape Professional training course.

Removing subjectivity from the debate about mountain biking being good or bad is very much the correct thing to do. Focusing on real issues rather than perceived ones helps landowners and riders understand each other better. Additionally, this approach makes it easier for them to build a positive working relationship. Photogrammetry for Trail Erosion Measurement allows us to monitor and quantify environmental changes.

Conclusively, such is the power of photogrammetry.