Tohamsan Mountain in Gyeongju tearing apart due to landslides and land slippages

In May, it was confirmed that a land slippage occurred in the mountain area in Hwangyong-dong, Gyeongju, North Gyeongsang Province, where traces of landslides were found. Courtesy of Green Korea

Land slippages have been confirmed to be underway in three areas around Tohamsan Mountain in Gyeongju National Park, North Gyeongsang Province, where traces of a large-scale landslide were found in May. A land slippage is considered to be more powerful than a landslide and can lead to the collapse of the entire ground when they encounter external shocks, such as heavy rain and earthquakes. Experts are concerned that the land slippages are progressing towards roads and villages, which is a dangerous situation.

On July 15, Green Korea visited Mujangsan Mountain, Hamwolsan Mountain, and Tohamsan Mountain in Gyeongju and found that the ground was pushed at three points in the northern and eastern parts, centering on the top of Tohamsan Mountain.

The land slippages were found to be in progress at an area of 12,231 square meters in San 116, Hwangyong-dong, Gyeongju, of 2,731 square meters in San 116-5, and of 4,852 square meters in San 286 Beomgok-ri, Munmudaewang-myeon. “The three sites are concentrated within a 5-kilometer radius, so a serial collapse is also possible,” said Seo Jae-cheol, a member of Green Korea.

A land slippage is a phenomenon in which weakened land slowly collapses on a large scale along a slope as groundwater rises. It usually progresses slowly, but it can collapse rapidly when there is an impact caused by heavy rain or earthquake. Unlike landslides, where only the surface collapses, land slippages can be 100 times more powerful and damage is known to be 100 times greater than landslides.

The land slippages in the Tohamsan Mountain area are of particular concern because they face roads and villages. In Hwangyong-dong, the flow paths of the two land slippages converge in a single valley and head to the 925 local road.

The lower part of the land slippage area in San 116 was about 350 meters from the road. “The slope is more than 35 degrees,” said Park Jae-hyun, a professor at Gyeongsang National University, an expert on land slippages, while watching the site. ”If it starts to collapse, it will take less than two minutes to reach the road.” In the event of a heavy rain or an earthquake, the nearly 15,000 square meters of collapsed soil and rocks could hit the road at any time.

The Hwangyongdong mountain area was already experiencing a landslide due to the land slippage. From small pieces of stone with a diameter of 20 centimeters to rocks more than 2 meters, the valley was filled with broken stones. The stones lay unsteadily, crumbling and rolling downhill with each step. "They are all phenomena of landslides," Seo said. "There are not many pieces of rock in ordinary mountain areas."

A land slippage was also found along the road leading from the top of Tohamsan Mountain to Beomgok-ri village in Munmudaewang-myeon.

This is right next to the site that caused the most damage among the 24 landslide areas identified in May, where up to a meter or more of the stratum was found to have subsided. While debris barriers are installed to prevent a certain amount of soil from flowing out, there is also a risk of hitting the village if landslides of a scale exceeding the capacity occur.

※This article has undergone review by a professional translator after being translated by an AI translation tool.