Over the past six months, tourists and local people have been shocked to see that Byron’s famous Main Beach is literally disappearing day by day, maybe because with water and debris. Resident Neil Holland said that In October 2020, people were forced to temporarily close the beach because they couldn’t find any rescue equipment onto the sand. He had lived in that area for past 47 years.
So now what is happening at the beach ? The erosion is taking place due to a process known as headland bypassing, and it is not like erosion or storms, it is something quite a different.
So how does Headland bypassing occurs ? This happens when sand moves from one beach to another. This process mainly takes place by wave energy.
However, sand does not flow evenly or smoothly along the coast, it builds up against the rocks and the beach and then gradually keeps on growing wider. When there is too much sand to hold, or there’s a change in the conditions of wave, some sand will be pushed around the headland – before it continues its journey up the coast
This large lump of moving sand is called as a sand slug. The sand slug needs the right wave conditions to move towards the shore. Or else the beach in front of the slug is deprived of sand and the waves and currents near the shore of the beach.
Headland bypassing was first described in the 1940s. Only about 20 years ago it was recognised as an important part of the process. Recent studies have shown that the wave direction is particularly important to headland bypassing.
In the past two months, a large amount of sand was present just near the north of Cape Byron, from Wategos Beach to The Pass Beach. As this sand pulse kept on growing, Clarkes Beach, and then Main Beach, were starved of their usual sand supply and hence they began to erode.
The sand pulse is visible from the satellite images starting from around April 2020. Each month, it slowly kept on moving to the westward into the bay. As the sand pulse kept on growing, the beach ahead of the pulse gradually kept on eroding. Right now, the Main Beach is at the eroding stage.
Similar erosion was observed at Main Beach in the early 1990s. The beach became started becoming wider again from the year 1995 and that continued till the year 2007. From 2009 onwards, the erosion of the shoreline slowly began again, and then it started becoming very noticeable since the past six months.
The effect of sand pulses on the beach erosion is not exclusive to Byron Bay beach. However in that case, the erosion risked the damaging of a holiday park and bowling club which was just nearby to it.
Mild waves from the east to northeast , will help some of the sand slug to move onto Clarkes Beach- Australia and then further along to Main Beach , which usually occurs from October to April each year. This normally happens over several months to a year in Australia. But it cannot be predicted exactly about the time when the beach will be fully restored.
This uncertainty underscores the need to better forecast these processes. And that would certainly help us to predict when bypassing sand pulses will occur and thus may help to manage beach erosion.
Climate change is expected to affect wave conditions in Australia. However, better predictions can help the community to be informed early about expected impacts, and the officials can plan better for future upcoming erosion.
Meanwhile, the people from Australia are waiting and watching that at least that the erosion problem will eventually improve.