The Korea Land Safety Management Agency, which plays a role in preventing ground subsidence (sinkhole) accidents, reviewed introducing a 'deep detection device' capable of detecting up to 20 meters underground this year, but it has been confirmed that the plans have fallen through. Currently, the depth that can be detected with the equipment held by the Korea Land Safety Management Agency is only 2 meters. Recently, as large sinkholes have increased in areas such as Gangdong District in Seoul, preventing such sinkhole occurrences with the current equipment is impossible.
According to the 2025 National Assembly briefing materials from the Korea Land Safety Management Agency obtained by ChosunBiz on the 14th, the agency included plans to introduce deep road ground investigation equipment capable of expanding ground survey ranges in its major operational plans at the beginning of this year.
The penetration range of the existing ground investigation equipment is 2 meters. However, the deep detection device has a penetration range of 2 to 20 meters, allowing for the prior detection of deeper underground spaces. By introducing the deep detection device, it will be possible to detect sinkholes at depths that could not be discovered previously.
The Korea Land Safety Management Agency reviewed the introduction of such equipment as part of its efforts to strengthen safety management of underground spaces amid the annual occurrence of sinkhole accidents.
However, the introduction of the deep detection device planned by the Korea Land Safety Management Agency has fallen through. A representative from the agency explained, "We concluded earlier this year that it would be difficult to introduce the deep detection device." The Korea Land Safety Management Agency did not provide further explanation about why the deep detection device became problematic.
However, analysis indicates that the decision by the Korea Land Safety Management Agency is due to the lack of proper performance verification for the deep detection device itself. A representative from the Ministry of Land, Infrastructure and Transport noted, "I understand that the deep detection device itself has not undergone performance verification," adding, "While reviewing the necessity of introducing the equipment is a priority, there are many technical aspects to consider, so (introducing the equipment) will take time."
As the introduction of the deep detection device is prolonged, the prior prevention of large sinkholes is expected to be limited. Currently, the Korea Land Safety Management Agency possesses only 10 units of Ground Penetrating Radar (GPR) equipment. The depth that this equipment can survey is limited to 2 meters. There is no prior detection equipment for large sinkholes. Consequently, the large sinkhole that occurred in Myungil-dong, Gangdong District, Seoul, on the 24th of last month was also preceded by a survey conducted three months ago, but no abnormal signs were detected. The size of the Myungil-dong sinkhole was 18 meters wide, 20 meters long, and 18 meters deep.
According to the office of Representative Jang Cheol-min of the Democratic Party of Korea, among the 10 units of equipment operated by the Korea Land Safety Management Agency, the depth of exploration for vehicle-mounted equipment is 1.5 to 1.8 meters, for sidewalk types is 0.6 to 1.5 meters, and for manual types is about 0.1 meters. A total of 264 sinkhole incidents occurred nationwide in 2023 and 2024.
As a result, it takes an average of four months to complete inspections even in response to requests from local governments. The average inspection duration in 2023 was 157 days, and it took 120 days in 2024 as well.
Meanwhile, the Korea Land Safety Management Agency plans to establish a 'Land Safety Verification Center' to ensure the reliability of diagnostic equipment necessary for sinkhole prevention. Performance verification of the deep detection device is expected to take place at the Land Safety Verification Center. The Korea Land Safety Management Agency has begun work on establishing the Land Safety Verification Center this year. Plans to enhance the installation and operational strategies for the center are set to be pursued by the second half of this year.