Aerial drones are being used for an increasing variety of projects by councils. For biodiversity, biosecurity and compliance monitoring; for infrastructure planning and inspection, and for emergency response situations.
Today we look at three Flightworks aerial surveys undertaken for the Bay of Plenty Regional Council, highlighting just some of the useful applications for drones.
Spartina monitoring – Maketu estuary
Spartina is a weedy grass being targeted for eradication in the Maketu Estuary. Having a good monitoring system to track progress towards this goal is key to success. Flightworks was engaged to provide a high-resolution orthomosaic image of the spartina infested areas in order to provide a baseline for this project.
For any project like this, it’s important to decide which image resolution will achieve your objective. Higher resolution requires lower altitude flying and longer flight times, increasing the complexity and cost of the orthomosaic.
For example, at Maketu we chose 1.95cm pixel resolution to broadly record the change in vegetation as per the project goals. Whereas, if we had needed to detect very small areas of spartina we would have chosen a higher resolution.
The series of images below give an indication of pixel resolution – in the photo from top to bottom is: spartina, a stick, mud with crab holes, and a sea rush.
“Hamish and his team at Flightworks have been great to work with and have provided a professional and high quality service. They invested time in planning the project with us to ensure they could provide us with the best product for our needs. The orthomosaic imagery has provided us with a valuable tool for monitoring and was able to be carried out much faster and more safely than could be done on land, or in the estuary!”
— Wendy Mead, Biosecurity Officer, Bay of Plenty Regional Council Toi Moana
Dune vegetation – Ohope spit dune
Rabbits are devastating the native vegetation across the Ohope spit dune so the BOP Regional Council is preparing a comprehensive pest control plan. To provide a baseline for the expected changes in vegetation as a result of this initiative and to plan for weed control, Flightworks were engaged to provide a high-resolution orthomosaic of the dune spit.
While flying, we also captured 10 aerial oblique photos from planned vantage points in the sky, which give a larger landscape perspective across all parts of the dune. These were documented as aerial photo-points so that they can be repeated. For photo-points, the client wears goggles with a direct view through the drone camera to assist framing the camera shots.
“After recently engaging Flightworks to undertake aerial mapping and photography for a Biodiversity Project I manage on the Ōhope Sand Spit, I would highly recommend them, especially when it involves operating in a public area. Flightworks had exceptional health and safety systems and were very professional in every aspect of their operation. The outputs were great and all the partners and I of the project were blown away with the results. This work has proven invaluable in helping plan detailed pest plant work, and will provide a great baseline for assessing on-the-ground changes over time.”
— Sam Stephens, Biosecurity Officer, Bay of Plenty Regional Council Toi Moana
Infrastructure planning – Tikitere stream
The BOP Regional Council is considering a water denitrification plant beside the Tikitere Stream. The plant would remove ammonia from the water in the geothermal stream to decrease nitrogen pollution of Lake Rotorua.
The site beside SH30 has recently been cleared of vegetation, which provided an excellent opportunity to create an accurate point cloud of the ground levels for engineers and planners to model the plant building positions.
Flightworks flew the site to create the point cloud and orthomosaic for the planning work. A set of six Ground Control Points (GCPs) were marked across the site and surveyed to 2cm accuracy. These could be clearly seen in the aerial imagery and the 2cm accuracy was conveyed through the processing into the final orthomosaic and 3D model.
“Flightworks provided superb high quality aerial imagery and point cloud data for the BOP Regional Councils Tikitere property and the data from this was used to design a nitrogen reduction plant. Flightworks were professional and thorough at all stages of the project from scoping project works right through to advising end-users on how best to use the data.”
— Robbin Britton, Consultant Project Manager for BOPRC
Talk to us
At Flightworks, we use aerial drones as a revolutionary tool to complement our expertise as ecologists.
Call me (Hamish) on 07 394 4394 if you have any questions about this article, or contact us if you’d like to discuss your project requirements.