South Korea's disappearing beaches

South Korea's Sacheonjin beach is a surfer's paradise, but fast economic expansion is chewing away at the waterfront.

It’s one of 43 beaches in the country facing "serious" coastal erosion.

The damage is driven mostly by dodgy development, and now people there face an unpredictable situation.

Guesthouse owner Choi Jong-min has watched the high waves wipe away major portions of the beach this year, exacerbated when a typhoon hit in August:

"The waters have never been this close nor the waves this high for the past 12 years. This place was famous for calm waves, but look, they are wildly breaking now."

Until 2019, Sacheonjin was as wide as 130 feet but during a recent visit by Reuters, the beach had narrowed to about 10 feet.

Early developers removed large sections of sand dunes to lay a coastal road, and seawalls were built too close to the shore, leading to erosion.

Professor at Kangwon National University, Kim In-ho explains how it all went so wrong:

"This (grass in the sand) acts as a reinforcement and is holding onto the sand. But all these structures (coastal road) have been built above it here. It (the erosion) is caused by these structures."

Some business owners said they have been forced to relocate.

In other spots, steep sand dunes as high as five meters have formed, triggering safety concerns and disrupting tourism.

Authorities plan to supply more sand and flatten beaches in the affected areas while devising long-term recovery plans.

But some experts say the damage has already been done.

"There are some artificial factors. Firstly, there is a reduction in natural influxes of sand from nearby rivers into the beaches as they are blocked by new dams and reservoirs. Secondly, structures that are installed near the beaches."

The construction of a floating dock designed to supply coal to a nearby power plant has compounded the problem.

Activists fear a planned breakwater at the power plant could also cause further damage, by diverting the force of the waves during storm surges to other parts of the beach.

Add to it all, climate change.

Rising sea levels and unpredictable weather are also threats to soft sand beaches like Sacheonjin.