In coastal management circles, Professor Andrew Short OAM is a celebrity, Australia’s Professor of Beaches. And in a country girt by sea and blessed by 12,500 beaches, Professor Short, of Sydney University’s School of Geosciences, has been to all of them to map, study, and categorise the lot. But it’s his dedication to the Narrabeen to Collaroy stretch we’re here to celebrate.
“I returned to Australia in 1975,” says Professor Andy. “I’d been living in America, and had studied beaches in Hawaii, Alaska, Florida, Brazil, from fine sand to cobble stone. And at that time in the literature there was no understanding of the range of the beaches.
“A beach has three simple ingredients. Sand. Waves. Tides. But the variety those three ingredients can produce is incredibly wide. And monitoring a beach through time could allow for better understanding of the entire range of the beach’s movements.”
In 1976, Andy decided to start monitoring the 3.6 kilometre Narrabeen to Collaroy stretch every day. He had 14 locations set up, and deployed “The Emery Method”, the technique he’d learnt in Alaska.
What is The Emery Method? “It’s fool proof”, says Andy. “You have two calibrated poles, a tape measure, a set benchmark, and with the two poles you get the difference in elevation and can measure and map the cross-sectional elevation – the profile – of a beach.”
For the first 18 months, Andy even did daily sketches, building an incredible time series of the beach’s movements. After 18 months, the operation was scaled back to monthly. The dedication lived on, unaware how valuable this information would become…
“I came on board in 2005,” says Associate Professor Mitchell Harley, from the University of New South Wales Water Research Laboratory. “As part of my PhD, I was offered the role to take the survey program into the future, utilising the new techniques available, which would also mean driving up and down Collaroy to Narrabeen every month on a quad bike. That sounded pretty cool.”
Mitch modernized the program with full 3D measurements made possible by quad bike missions. This was complemented by 5 cameras atop the Flight Deck building, which have taken a photo of the beach every hour for the past 20 years. Drone technology then took over, and more recently, satellites with coastal imagery dating back to the 1980s can be deployed.
This is where it really gets interesting. When data sets from modern, far more sophisticated means are matched against those from Australia’s Professor of Beaches, the difference is statistically insignificant. As Andy’s son Ben remarks, “Thanks to Dad’s data sets, those can be used to validate the new technologies, which allows for mass surveying of beaches across the planet.”
The implications are immense. “The satellite techniques are ultimately to find better ways for humans to co-exist with dynamic shorelines,” says Mitch. “For instance, this technology developed at Narrabeen from Andy’s data was recently used in a Washington Post article about houses eroding away in North Carolina.”
Further, there’s now reliable capacity to model every beach on Earth, categorise their safety, reducing drownings, and enhanced tools for better foresight, planning and coastal management, allowing reduced need for unnecessary seawalls.
Hats off to Andy, Mitch, and so many more for 50 years commitment to the Narrabeen to Collaroy coastal monitoring program, a monumental effort that can now pay dividends for the entire world.