Using Aerial Photographs to Support Conservation Projects
As part of our Darwin Plus project, we’ve been creating orthomosaics of each sub-catchment (Grapevine Gut and Wells Gut) and a 3D model to visualise the topography. Using software provided by Pix4D and DroneDeploy, the project team processed hundreds of photographs taken using a DJI Phantom 4 drone to create the images and visualisations.
The orthomosaics have been used to plan ecology surveys of Wells Gut and Grapevine Gut and to evaluate the canopy cover to determine the proportion of endemic and invasive species in each sub-catchment. Recognising that a canopy survey can only see the highest vegetation in the cloud forest, the team then selected a number of locations in each sub-catchment to ground truth the data and assess the understorey.
Orthomosaic images of Wells Gut and Grapevine Gut are presented on the left and have been used to support ecology surveys on Saint Helena. The images have also been used to create Digital Elevation Models (DEM) and NDVI maps. The DEM’s have been used to develop catchment maps for each sub-catchment using the software package Surfer, published by Golden Software. The orthomosaic images, NDVI images and DEM’s were produced using Drone Deploy using images captured from a DJI Phantom 4 quadcopter.
