Coastal mapping for Shire of Gingin and Department of Transport

Coastal mapping for Shire of Gingin and Department of Transport

The Shire of Gingin engaged Land Insights to capture aerial imagery of the coastline from Seabird to Ledge Point to Lancelin. The project objective was to monitor coastal dunes in the area, to better understand how they responded to changes in the seasons, including storm events.

The aerial data we collected and processed would be used by the Shire to make more informed decisions regarding ongoing coastal management. Aerial imagery was captured over autumn and spring in 2021, and in winter after a major storm.

 A land survey was also commissioned by the Shire (with funding support from the Department of Transport) by ProSurveys. The data collected by our team and ProSurveys would create a comprehensive picture of seasonal changes to the coastal area for the Shire to work with.

Here’s more on this coastal management project for the Shire of Gingin.

Overview

We captured aerial imagery of terrain along the Seabird, Ledge Point and Lancelin coastline, using a drone (also known as a Remotely Piloted Aircraft or RPA). This data was then processed into a georeferenced orthomosaic – a high resolution map created using smaller images (known as orthophotos).

Orthomosaics are valuable to clients who require a high quality visual of specific terrain during certain time periods. They’re sharper than Google Maps, and are corrected for camera tilt, lens distortion, topographic relief (changes to the surface of the earth) and perspective. All of these factors make orthomosaics highly uniform and accurate

Our team also developed a digital surface model for each location, and a 3D high resolution model of the Seabird sea wall. This 3D model was developed for the Shire of Gingin at no additional cost.

Benefits of Coastal Mapping

Capturing a clear visual of the coastline over different seasons within the same year enabled the Shire of Gingin to better understand which areas of the coastline could be threatened in the future. This helped the Shire to:

• Better understand the dynamics of the vulnerable Gingin coastline.
• Make more informed planning decisions with the Department of Transport.
• Determine which towns could be impacted by future changes to the coastline.
• Identify issues such as beach accretion (where the beach gets larger in certain areas).
• Power modelling associated with the Seabird sea wall.
• Perform coastal management, coastal risk management and adaptation planning based on accurate data.

Challenges

Approvals

When flying a drone or RPA in any location, it is vital to ensure requisite approvals are obtained for the airspace. In this case, numerous restrictions were in place for the area, so approvals from relevant authorities were required before launch.

Our team liaised with Pearce Airbase for approvals. We had worked with Pearce Airbase in the past, and were able to secure pre-approval before flying. Flights were typically scheduled over the weekend, so as not to interfere with military training in the area.

Weather conditions

Mapping long corridors of terrain can be challenging when weather conditions are poor, especially when additional control points are required for accuracy. Flights were scheduled in the morning, when strong winds were less likely to affect the drone.

We also kept a close watch on the Bureau of Meteorology’s weather reports, to ensure drone flights occurred when the weather was suitable. This meant ensuring approved fly dates aligned with optimal weather conditions.

Find out more

For more information on how we assisted the Shire of Gingin with their coastal mapping and planning requirements, please get in touch.

Our drone pilots are certified with the Civil Aviation Safety Authority (CASA), with Remote Pilot Licences (RePL) and Remote Operator Certificates (ReOC). We work with local and state government clients across Western Australia, and we are happy to assist you too. Contact us for coastal management planning support.