Getting the best from data: DAS, data collection and survey design

Transect based design is recommended as a cost-effective data collection method to survey large or regional spatial scales. APEM Group undertook transect-based surveys in the world’s largest aerial survey over New York, as well as in North and South Carolina and off the coasts of Ireland and Scotland.

With a retrospective view, and with advances in technology, we recommend a grid-based design for gathering precision data for population estimates, risk levels and mortality rates for EIA purposes and from an approvals perspective. This is especially important in areas where there is uncertainty or a lack of data in OSW sites and buffers, as baseline data must be as rigorous and defensible as possible. An even sampling regime provides confidence that the data remain fit for purpose, with the same coverage levels where project sizes and shapes change over time. By sampling a whole area, we can ensure no further surveys would be required if plans change, so no additional survey effort or hidden costs for extra modelling would usually be required.

Knowing which species are present, where they reside in the project site and what times of year they naturally occur are key questions to manage the EIA process. Advances in technology and the right survey design enables us to gather more robust and accurate data to answer these questions, adding confidence to developers and regulators.

LiDAR: the next step in the evolution of DAS

Using digital aerial surveys, subjects are photographed from 400m above sea level. With this technique, there remained a small degree of uncertainty: is the bird a small example of its species, or is it just flying at a lower altitude? With this uncertainty came tighter regulations to ensure all possibilities were mitigated for, slowing the consenting process and, in some cases, halting it altogether.

Members of the APEM Group Geospatial Insights and Marine Wildlife Surveys teams came together to develop a novel approach and an innovative solution to add certainty for regulators and developers. Read the next article in our series to find out more about the APEM Group-developed LiDAR technology that has taken it to a global best practice approach.

There are a number of reasons why we recommend LiDAR as a standard for Australian OSW developers:

• Flight heights calculated using DAS alone are no longer accepted for consenting in Europe. Recent regulator outputs have raised questions about the confidence in size-based estimates and a movement towards LiDAR for flight height assessment
• Quality data adds confidence and reduces uncertainty in OSW planning, increasing the chances of gaining consent on time and on budget
• There is little current literature and baseline data on marine wildlife in Australasian waters
• There are more species in the seas around Australia,where up to 70 species have been recorded in the Gippsland region alone to date from the limited surveys undertaken

The next article in our series will explore why LiDAR is now seen as a gold-standard approach that has been highlighted by Natural England, the statutory advisory on nature conservation in England, how LiDAR works to accurately assess bird flight height and how it adds confidence to our clients in OSW.

Advances in science and technology have driven improvements and cost efficiencies to the renewables industry globally. Led by science, a learning mindset and commitment to core scientific principles, APEM Group are considering the next steps in the evolution of survey methods, including drone technology, AI and considering evolving regulations across the world. Keep an eye on our Technology Innovations page for new developments.

*Adapted from McGovern S. et al. (2019) The First Large Scale Offshore Aerial Survey Using a High Resolution Camera System. In: Bispo R., Bernardino J., Coelho H., Lino Costa J. (eds) Wind Energy and Wildlife Impacts. Springer, Cham.