We use aerial imagery to monitor and analyse the impact of conservation works across vast, open moorlands to give us a picture of our works at a landscape scale.
We still use traditional surveying methods to monitor vegetation, water flows, water table and peat depth; aerial imagery adds another tool to the monitoring toolbox, allowing us to monitor at a bigger scale. For example, a traditional monitoring site is 0.01 square kilometres in size and contains 10 quadrats for monitoring vegetation. From the air, we can collect data across an area of 0.5 square kilometres in one flight. The aerial imagery collected can be analysed to produce maps showing the type and extent of vegetation and land cover.
We are particularly interested in monitoring blanket bogs that have become dominated by single species such as cotton grass, purple moor grass and heather, as well as areas that were previously dominated by bare peat. We have chosen areas that feature these characteristics to monitor; these have become our field ‘laboratories’. In 2018 we collected baseline data to measure the effects of successive conservation works against.
Each ‘lab’ has been ‘flown’ three times to collect three different types of images: true colour, multi-spectral (different vegetation types appear on computer as different colours), and thermal images which indicate the wetness of the moors.
The images were ‘stitched together’ and geo-referenced using ground control targets with special software, so that we know exactly which photo is which bit of moorland. This is helped by the fact that our GPS is accurate to 2cm. We plan to compare future changes against the vegetation cover data.
In one such experiment, we are planting 11 different species of sphagnum, with their precise locations input to ‘train’ the computer software to recognise the different species.
The use of UAVs is subject to safety rules, which are underpinned by UK law. Our team members need all the correct permissions in place before they can fly, including from the Civil Aviation Authority (CAA), Natural England, and individual landowners and tenants. They also have to follow the ‘Drone Code’, launched by the CAA last year, ensuring they abide by rules such as staying below 120m (400ft) in altitude and keeping a safe distance from people and property.
Using aerial imagery to monitor vegetation at a landscape scale, rather than the traditional site scale.
We’re creating a database to record wildfires on the Peak District and South Pennine moors
We have created a detailed map of the location and extent of the different habitats and land covers present in the Peak District and South Pennines