Time to get serious about rising sea levels

Main Beach Noosa Seasonal Erosion Is Getting Worse

While teenaged climate change warrior Greta Thunberg’s death stare and dramatic call to action was attracting more attention at the UN last week than any visitor since Nikita Kruschev took off his shoe and pounded the table nearly 60 years ago, a much lower-key event at a safe height above the Med in Monaco launched the sober findings of the Intergovernmental Panel on Climate Change’s 2019 report.

We’re getting used to hearing alarmist reports on every aspect of climate change, but the IPCC report provides the most definitive scientific evidence yet of warmer, more acidic and less productive seas. Glaciers and ice sheets are melting, causing sea levels to rise at an accelerating rate. Basically, our oceans are screwed and Australia’s coastline isn’t much better, and the best we can hope for is mitigation of the consequences through serious emissions reduction and carbon sequestration.

“Our oceans have changed,” Australian Nathan Bindoff, a report co-author, and one of the world’s leading climate scientists, told the ABC. “The global ocean has warmed unabated since 1970, and the rate of warming has doubled since 1993, so we are totally convinced the oceans are warming up.”

In Australia, where 85 percent of our population lives within 50 kilometres of the coast, we will need to adapt our coastal cities and communities to unavoidable sea level rise. There are a range of possible options, from building barriers to planned relocation, to protecting the beaches, coral reefs and mangroves that provide natural coastal defences. But perhaps the most responsible thing we can do for future generations – other than reduce emissions – is to monitor and manage the evolving situation, particularly in places like Queensland’s Gold and Sunshine Coasts, where there is a growing population and a growing visitor base, a large percentage of both attracted by quality waves.

While many surfers regard the increasing incidence of extreme weather events as an opportunity for more frequent Coral Sea swells and East Coast lows, others, like Noosa-based surfer/scientist Dr Javier Leon, are taking a broader view and using their surfer’s knowledge of the sea to promote the use of new technologies to monitor and protect our coasts.

Says Javier: “The beaches of the Sunshine Coast are a critical environment and resource for the region, but they are also the most susceptible landform to coastal hazards such as inundation and erosion, which are forecast to increase. Managing the risk requires investment in measurement, monitoring and modelling to enable short-term response and long-term planning.”

Dr Javier Leon Launches A Drone To Record Changing Sand Volumes

The problem is that collecting accurate data in high energy surf zones can be dangerous to people and instruments, and traditional methods used to survey the coastline are costly and time-consuming, and therefore only used sporadically. Which is why Javier, and other surfer-scientists, are championing the relatively low-cost use of those wonderful tools of trade of the modern surf media, the drone and the webcam, as part of a cost-effective coastal imaging system. This method uses images obtained from fixed cameras and drones, and applies cutting edge analysis to frequently map the position of the shoreline, changes in beach volume and the shallow bathymetry (the shape of the ocean floor that influences wave formation), as well as monitor beach use.

While coastal imaging systems have been in use along parts of our coast for more than 20 years, improvements in technology, the introduction of the concept of “citizen science”, and growing evidence of rapidly rising sea levels mean that the time is right now to build on our understanding of what is happening on our doorstep. The pilot program that Javier and his colleagues at University of Sunshine Coast’s School of Science and Engineering hope to initiate along Noosa’s beaches and points will use a combination of video cameras, drones and “Coastsnap” stations, or fixed position cameras, which allow citizen scientists to feed their own smart phone coastal observations into the data bank.

Citizen science is a great way to get young beach users, and the broader community, involved in the issues that threaten our oceans and our beaches, and as Javier and his team reach out for financial support to make this happen, the Noosa World Surfing Reserve will be one of many ocean-based organisations behind them all the way.

For further information about the Noosa coastal imaging project, contact Javier Leon at jleon@usc.edu.au

Drone Documentation Of Beach Volume


AUTHOR

Phil Jarratt – Noosa World Surfing Reserve President 

CAPTIONS

Main Beach Noosa seasonal erosion is getting worse.

Drone documentation of beach volume.

Dr Javier Leon launches a drone to record changing sand volumes.