Ex-tropical cyclone alfred gouges 500 km of coastline

Waves as high as “three or four-storey buildings” emerging by ex-tropical Cycloon Alfred have millions of cubic meters of sand from about 500 kilometers of coastline between Coffs Harbor in New South Wales and the Sunshine Coast of Queensland.

Ex-Cyclone Alfred has so extremely caused to flow erosion that it is left up to six meters high in some dunes, including on iconic tourist extensions of Gold Coast.

University of Newcastle Coastal Erosion expert Michael Kinsela said that the outcome of the wrath of the Cycloon – with its processed waves up to 15 meters high – should not be seen as all the bad news for the tourist places in Australia.

“Undoubtedly the erosion is serious and the photos are very dramatic, but what I see are photos of eroded beaches and dunes, no photos of roads that fail in the sea and sea walls,” said Dr. Kinsela.

“In that sense it is a very positive result and something that Coastal managers are planning.

Dr. Kinsela praised the coastal management of Australia, in particular on the Gold Coast, for maintaining beaches and dunes that protect the infrastructure on the waterfront against the severity of a rare cyclone that dares so far to the south-the first to cross the southeast coast of Queensland in more than half a century.

“The way they manage sand on Gold Coast beaches is through a sand pump system that moves sand from the south of the tweed in NSW,” he said.

“There has now been a method with several decades to ensure that there is enough sand on the beaches of Gold Coast. The buffer of sand that was there is intentional and has protected almost all infrastructure of the Gold Coast Waterfront.

“The sea wall also runs in front of the road along the waterfront of the Gold Coast, so they have had no waves that attack the road.

“The beaches are damaged, but that is preferred above the roads and buildings that are damaged.”

Complex questions for recovery

Dr. Kinsela said the question of how long it would take to recover beaches was “complex” and would depend on problems in the coming weeks when the weather.

Rare gigantic waves that come from the east, generated by ex-tropical cyclone Alfred, pounded east coast beaches and robbed them of sand in the days prior to the landing.

But Mother Nature will eventually send the sand back to the coastline as soon as the swellings are normal again.

“This is an important event. It will take weeks to months to have what people can call ‘beautiful’ beaches again, but the beaches will be there and waves will start to return the sand next week.

“There is a lot of active sand management at the Gold Coast. There will probably also be some remediation works to speed up things.

“We can have more storms and more erosion. What we hope is that we now just have a series of truly stable and constructive swellings and the sand is simply returned quickly.”

Coastal managers and researchers used drones and laser scanners to map the beach topography of Australia in detail prior to ex-tropical Cycloon Alfred.

That will be repeated after the storm to measure the impact.

Dr. Kinsela said it was too early to say exactly how much sand cyclone that Alfred had taken from the beaches of the east coast, but it would be in the “millions of cubic meters”.

He said it was also unclear, until the measurements entered, where the Cyclone rated in terms of historic Stranderosie events in Australia.

But he said it was unlikely that it would surpass the erosion in NSW in 1974 or the worst beach erosion of the Gold Coast in 1967.

“It is when we experience a series or cluster, of very extreme storms in just a few months that the worst erosion -consequently and the slowest recovery times occur,” Dr. Kinsela.

“An extreme storm in itself can be harmful, but if the beaches and dunes are healthy before such a storm, the effects are … hopefully limited or at least not too serious.”